K1 / K2 spring kit

[Hakie]

A few weeks ago i changed oil and filter of an automatic transmission from a friends W126. He had troubles with hard shift and slipping gear. For that reason we also replaced the K1 and K2 springs. He ordered the parts as i have no experiance with this K1 and K2 spring kits!
It turned out to be a major improvement for the transmission. It shifts very smooth now, almost perfect.

When i am going to change oil and filter for the E500 and 400E i want to replace the springs also and hope to get an improvement in shift too. Also as a "while i am in there" thing.

What i know about the spring kit is:

The K1 spring kit (new type) is universal and has partnumber A126 270 4477
That should fit in our transmissions?

The K2 spring kit has multiple partnumbers: A126 270 xx35
Witch one should i order for our transmissions?

I searched the forum for this subject but could not find anything pointing to this partnumbers?

The costs of the kit's ordered at the dealer are under $10 each, so that is why i think it is worth it to replace them?




From Gsxr's site:

 

[samiam44]

There have been some changes to the springs through the years. Some of those springs were in a TSB on our ng, some are for 722.4xx, and some address specific issues. The K2 is the example there.

There is a superior shift kit available for ~ $45. It has several options for making the shifts firmer or softer.

Those kits are the accumulator kits. I went through last year and ordered every one available and experimented. No notes in my hand- but I believe for most(unless you have a broken spring), that you can replace the K2(effecting 2-->3 shift) and move the old K2 into the K1 position. Monkeying with the shift kit plan on removing and changing springs 2 or 3 times. K1 and K2 are on either ends of the same spool. So changing one effects the other...

You can turn up the pressure slightly which will quicken shifting. Clean fluid will improve shifting.

Is it worth replacing them? If you are not experiencing a problem- don't touch it. If you want to improve something- please give us more details on how it is shifting.


I've got a 1992 first gear start valve body built with improvements, just hasn't been tested yet.

Michael

 

[Hakie]

There is a superior shift kit available for ~ $45.....

Is it worth replacing them? If you are not experiencing a problem- don't touch it. If you want to improve something- please give us more details on how it is shifting.

Michael

Thanks Michael,

I have 3 cars with automatic transmission. All of them shift ok, but can be improved because the shifts 2-3 3-4 can be "firm". Not really something to worry about but when this can be fixed with new K1 and K2 springs, why not do that? It dont costs much.
I read about the superior kit but thought of keeping the partnumbers original Mercedes.
After replacing them in the W126 the other day i was surprised of the effect. Better than only an oil and filter change.
Is it not so that the springs wear out a little after so many years and replacement is a good thing?
My thought was to change the springs as a job while i am in there. There must be a valid K2 mercedes partnumber for 400/500 transmissions?
Changing the springs only still is a time consuming job so i prefer not to experiment with that. When i am not sure about the right parts i will leave it alone.

 

[spkalka]

I have the superior Shift Kit installed in my 560SEC and also in my 300CE and it greatly improved the shifts and got rid of the occasional flaring on the 300CE.

 

[Eno]

I ordered a month ago a sring ‘kit’ made of 21 or 22 springs for my 92 500E but I don’t remember what was it called exactly?


Sent from my iPhone using Tapatalk Pro

 

[gsxr]

The K1 factory spring upgrade (126-270-44-77) will slightly firm up the 2-3 upshift. You only want to do this if the 1-2 and 3-4 shifts are normal, but 2-3 is soft or flaring. Also, it's possible a previous owner may have already installed this, can't tell until you remove the old one and measure the wire diameter on the springs (they are 0.1-0.2mm thicker on the new springs). I'm not aware of any factory spring upgrade for the K2, which affects the 3-4 upshift.

The Superior kit allows going even firmer beyond what the 126-270-44-77 will do, along with parts to adjust other shifts. Again, unless you are having shift issues, I wouldn't mess with anything. Pics of the Superior kit, and their instruction sheet, are here:
http://124performance.com/images/W124_transmission/Superior_springs/

 

[Eno]

Where can one buy the so called Superior Kits?
Are they after all market?
Does MB produce such Superior Kits?


Sent from my iPhone using Tapatalk Pro

 

[gsxr]

The Superior (brand name) kit is available from various vendors in the USA, including sellers on eBay. Here's a couple links:

https://www.google.com/search?q=superior+K722A-G

https://www.google.com/search?q=superior+K722A-G&source=lnms&tbm=shop

Links above are for the 722 kit for gas engines. There is a different kit for diesels.

 

[spkalka]

https://superiortransmission.com/product/superior-k722a-d/

The last one I ordered on ebay for $85 shipped. The one before also from ebay for $65 shipped.

 

[Hakie]

After contact with the owner of the W126, these are the 2 mercedes partnumbers we build in the transmission. I will order the 2 and decide when i change fluid and filter If i replace the spring kit's. I think he payed only 12-14 dollar for the 2 kits.
Thanks for all the input so far!



Found some extra info of the K2 kit:

https://www.ecstuning.com/b-genuine-mercedes-benz-parts/k2-piston-repair-kit/1262700535/

 

[samiam44]

Hakie,

Maybe you need to lower the line pressure slightly if all your shifts are too firm? As a rule, springs don't settle if made properly. Manytimes, you will find a broken spring where a rust pit had started and it failed with fatigue cycling. You can read the superior's information, but I know it has several springs for each K1 and K2. I think you can go softer, firm or extra firm. MB kits are nice between the color coordination and you get new seals.

 

[gsxr]

Uou can read the superior's information, but I know it has several springs for each K1 and K2. I think you can go softer, firm or extra firm.

IIRC, Superior only offers firmer-than-stock for K1 (2-3) and K2 (3-4) upshifts, and only offers a softer-than-stock modification for the 1-2 upshift.

If you are picky about shift quality, it can take a lot of trial and error experimentation, with 1-2 hours labor each time to drop the pan and/or valvebody (if necessary). Not fun!

 

[Hakie]

Hakie,

Maybe you need to lower the line pressure slightly if all your shifts are too firm? As a rule, springs don't settle if made properly. Manytimes, you will find a broken spring where a rust pit...

Yes Michael, i think the best thing to do is inspect the springs first and than decide what to do. It is not a big problem in my case. Also it is a bit complicated for me to explain the situation. I find therms as "hard, harsh and firm" shifts.
Maybe i just have to live with it. The cars are all 20+ years old and that comes with some wear in the trans.
Also the oil and filter change can change the feel of shifting. The cars are in winter season soon. In that period i will do de transmission maintenance.

 

[gsxr]

The type of ATF can change shift quality... in general, fully-synthetic can provide slightly more consistent shifts between cold and hot. If you change from a Dexron-III spec (7.5 viscosity) to a Dexron-VI spec (6.0 viscosity) you may need to adjust the vac modulator, and/or possibly fiddle with some springs. I prefer to use the fluid spec the 722.3/4/5/6 was originally designed for (7.5 cSt) but that's just me. There's been discussion / debate about this in other forum threads.

Also, if ALL the shifts are too firm or too soft, this can be adjusted via the vacuum modulator. If the vacuum modulator is original or old, it is not a bad idea to replace it, I had some intermittent odd shifting (flaring, IIRC) on one transmission which was cured with a new modulator.

 

[jhodg5ck]

If you get clever you can firm them ALL up...I don't have my notes in front of me but b/w doubling up on springs, seeing what can be made to fit where you can build one AGGRESSIVE valve body.

...it makes for a good time

 

[Christian_K]

The K1 factory spring upgrade (126-270-44-77) will slightly firm up the 2-3 upshift. You only want to do this if the 1-2 and 3-4 shifts are normal, but 2-3 is soft or flaring.

Very important note! Please do consider this.
Normally its used because 2-3 upshift ist the most used shift on these boxes and it wears out at first (besides the reverse). So its starts to get super soft (and long) and then flares.
On my gearbox i did this spring update preemptively without knowing the gearbox, nor driven it. The result is that all shifts are good, but the 2-3 is veeeery quick and clearly noticable. I played around alot with the modulating pressue which adjusts shift speed and softness for all gearshifts, but when i do the pressur so that 2-3 shift is perfect, all other shifts are tooo soft and take to long (almost flare).

 

[whatever]

On my gearbox i did this spring update preemptively without knowing the gearbox, nor driven it. The result is that all shifts are good, but the 2-3 is veeeery quick and clearly noticable. I played around alot with the modulating pressue which adjusts shift speed and softness for all gearshifts, but when i do the pressur so that 2-3 shift is perfect, all other shifts are tooo soft and take to long (almost flare).

So you mean, if I want to swap a transmission, I shouldn't do it? As it's what I'm just intended to do.
Never driven the trans, should be just fine. 600SEC though. And my car isn't stock either. (510hp)
Okay, maybe, I'll get a fluid flush and we'll see how it goes. Also I really want the 1st gear start badly.

Anyway, I stongly recommend anyone to use Dexron-II in the gearbox. DxIII is way weaker and burns clutches. DxII makes shifts quick and stable, although feels strange when cold.
I'm looking forward pouring Redline Type-F ATF with 10cct viscosity index.

 

[samiam44]

Whatever?

"Anyway, I stongly recommend anyone to use Dexron-II in the gearbox. DxIII is way weaker and burns clutches. DxII makes shifts quick and stable, although feels strange when cold.
I'm looking forward pouring Redline Type-F ATF with 10cct viscosity index. "

What brand are you purchasing D2 fluid? I don't understand what you mean when you say a fluid is "weaker and burns clutches". Is the viscosity lower?

I'm running redline in mine now- shifts are fine. Quick and crisp with the v/b changes. But it was a lot of work. For most, I bet they can do a shift kit/new flluid and then play with modulator pressure a bit and be happy- if the transmission is healthy. Type F fluid has [no] friction modifiers and seems to help if you have glazed some discs. It may help, but you should start saving coins for a rebuild.

 

[whatever]

Yeah, I know that Type-F has no friction modifiers, which is good. A friction modifiers decrease friction. With few cars on Dexron-III or universal ATF (Castrol universal ATF, Chevron D/M, as recommended by some 722.9 trans guru), I've experienced weak clamping force, overall smooth behaviour of 722.3, which is not what it's intended to do. I managed to flush the system with simple Mobil 220 and became brilliant. No clunking or whatever at idle, but great clamping force and strong shifts. Which is what I like when my right foot is heavy.
Now I thought, maybe I was wrong, allowed a Chevron D/M fluid flush with a v/b interchanged on my other 722.3. And it cooked up within half a year. It was really better on Dx2. So... no.. I think I'll never use anything other than Dx2 in 722.3. I wanted to try synthetic Dx2, but found out that it's lower viscosity. So only option is get a big trans radiator if you want a stable Dx2 operation. Or maybe try Type-F as well. Redline's Type-F is 10cct. So it's a little like mid-cold Dexron-2.

I wonder what happens with high modulator pressure on type-F? is it faster?
My intention is to make the trans shift faster with higher pressure. But logic tells that due to higher viscosity the actual shift time may not be fast.

Also on a new old stock E500 trans under heavy acceleration I've had 2-3 flare. Tried to correct it with higher pressure, went better, until the fluid heats up too much and a slight flare appears. The fluid was Dx2 though. That's probably when you should get ...4477 2-3 flare kit.

 

[samiam44]

Understand now Alex- sorry I was a little slow or harsh.


I think modulator pressure shortens the shift time. It fills the accumulator thicker- now cold. With cold weather running you might experience- I would do Redline race which is a thicker type-F. I've experienced recently a 2-3 flare and it was corrected by checking the fluid level which was ~ 0.5 liter low.
I think the synthetic versions are better as the viscosity range is narrower over operating range. My aux trans cooler fan seems to run most when idling at a stop. I think someone mentioned racing and only seeing transmission temp of 200F on the track.

Michael

 

[jhodg5ck]

Yeah, I know that Type-F has no friction modifiers, which is good. A friction modifiers decrease friction. With few cars on Dexron-III or universal ATF (Castrol universal ATF, Chevron D/M, as recommended by some 722.9 trans guru), I've experienced weak clamping force, overall smooth behaviour of 722.3, which is not what it's intended to do. I managed to flush the system with simple Mobil 220 and became brilliant. No clunking or whatever at idle, but great clamping force and strong shifts. Which is what I like when my right foot is heavy.
Now I thought, maybe I was wrong, allowed a Chevron D/M fluid flush with a v/b interchanged on my other 722.3. And it cooked up within half a year. It was really better on Dx2. So... no.. I think I'll never use anything other than Dx2 in 722.3. I wanted to try synthetic Dx2, but found out that it's lower viscosity. So only option is get a big trans radiator if you want a stable Dx2 operation. Or maybe try Type-F as well. Redline's Type-F is 10cct. So it's a little like mid-cold Dexron-2.

I wonder what happens with high modulator pressure on type-F? is it faster?
My intention is to make the trans shift faster with higher pressure. But logic tells that due to higher viscosity the actual shift time may not be fast.

Also on a new old stock E500 trans under heavy acceleration I've had 2-3 flare. Tried to correct it with higher pressure, went better, until the fluid heats up too much and a slight flare appears. The fluid was Dx2 though. That's probably when you should get ...4477 2-3 flare kit.

Good questions..

On the type F I find I can Typically dial back modulator pressure some and still keep Quick/Positive shifts. One of the Many reasons I'm such a fan of F...be it conventional or synthetic (redline racing atf is the most reliable source these days).

What/where are you running your car hard enough to really get the trans HOT...? We do endurance racing w/ the track rat so she gets 2.5 hour stints 8-10 hours @ a clip. Right now we're running a large hayward And the trans cooler from a W140 S600 Euro..even comes with a nice little fan that we have switched for when we come into the pits.

I think you would Really like the Redline fluid. I sure do!

If you REALLY want a bangin' valve body rock out that Superior kit. the directions kinda suck and you might have to improvise a little for the 1-2 shift but it does a damn good job.

jono

 

[Hakie]

Last week i did the oil and filter change on the 400E. Also while i was there, changed the K1 and K2 spring kits. I am not sure what cured what but the transmission shifts as i would like it. Sometimes cant even notice up-shifting.
I think the new filter and oil also did good, maybe all. I would not be surprised if it was the first time the whole transmission was drained.
First time job on the 400E. (Not a car mechanic) I left the cross-over exhaust in place. That was kinda pita and i will never do that again. Sure was a good "exercise" for the job to my E500. Will do that coming winter.
I used oil and filter from the dealer.
Only thing i have noticed is while downshifting manually from 4-3 the shift is hard. Any idea's to solve this or is this not to worry about?

 

[IslandMon]

I purchased and installed a rebuilt transmission from Sun Valley last summer, and installed a FGS valve body . Overall the FGS is great, and new tranny feels better than the old. I messed with the bowden cable and modulator quite a bit to get the tranny to shift as well as it is now.

I have a few shift issues that I was able to make a little better with modulator adjustments, but am hoping to make the shifts a little better with the Superior spring kit.

Before I dive in and start replacing K1 , K2 and B1 springs, I figured it would be a good idea to check with the group here to see if anyone has recommendations based on my symptoms.

First: the 1-> 2 shift is rather harsh, at varying throttle positions, but most noticeable at light throttle. It certainly is something I could live with, but would be nicer if it was a little softer.

Second: the 2->3 shift is a bit soft.

Based on what I have read on the forum, the K1 may help the 2-3 shift, and the new B1 spring may soften the 1-2 shift.
I am running redline d4 high temp synthetic ATF. I also purchased tve OEM k1 kit from naperville, not sure if Superior or OEM is better than the other for K1 upgrade.

Last question: is it worth replacing the cylindrical plastic pieces in K1 and K2 while I’m in there? I assume they last the life of the tranny, but not sure if the seals are replaceable.

 

[gsxr]

First you need to see what springs are in the FGS now... the factory K1 "upgrade" tends to be a bit firmer than stock, but Superior allows even firmer options if desired. The only way to get a softer 1-2 is via Superior.

The green cylinders for K1 and K2 are available new, IIRC, but you'll need to swap springs around. The new green K1 cylinder comes with springs that are waaaay too soft for an M119 (think they are meant for a 722.4 with a low-torque engine).

Side question - were all the shifts OK with the old VB, and you only have issues with the "new" FGS VB?

 

[IslandMon]

Side question - were all the shifts OK with the old VB, and you only have issues with the "new" FGS VB?

Unfortunately I don’t know because I installed the FGS valve body as part of installing the rebuilt transmission.

I’ll see whats in there now and use superior springs as needed. I’m planning to disassemble the VB that came with the rebuild to see how springy everything is under the large cover over B1 spring, so I don’t have to find out the hard way on the garage floor.

Thanks for the intel

 

[IslandMon]

The only way to get a softer 1-2 is via Superior.

Took apart the old VB on the bench to find out what happens when the B1 cover is removed with the VB resting horizontally.

Upon reviewing the Superior kit instructions again, it says that for softer 1-2 shift, the spring on the B1 accumulator control valve should be replaced first (step 6). This requires dropping the VB so the gate can be pulled, to get the accumulator control valve spring train out. Does anyone know if you can just replace the spring on the B1 accumulator (step 7), so the VB doesn't have to be dropped snd separated?

For K1 and K2, the instructions say the accumulator control valve springs should be replaced first, which requires dropping and separating. From everything I have read online, seems like people just take the easy route and replace the K1 and K2 springs that are easily accessible under the metal covers, without removing the VB.

Any tips or lessons learned would be appreciated.

 

[liviu165]

Guys, let's assume that someone wants to replace also (all or only some of) the plastic pistons or spring plastic holders inside the VB at the time of the spring(s) swap. The parts are not expensive. I looked in EPC for both my cars and could not find the plastic VB internal components, all EPC lists is the entire VB.

From the posts and pictures of this thred I can clearly see that MB has those parts included in the repair kits. So, here is my question: I don't mind buying the entire kit just to use the plastic parts, but how/where can I figure the right part numbers for my transmissions so the plastic parts in the new kits are identical with the ones I have in the VB? I hope that the answer benefits other forum members too.

TIS,
Roy

 

[gsxr]

Only 2 of the colored plastic pieces are available new (K1 and K2, and these require swapping springs around). The B1 plastic is not sold separately, or at least I've never found a part number for it. There is no "kit' with all the pieces that I know of.

 

[LWB250]

Do these guys have the parts?

http://www.transmissionpartsusa.com

I know I"ve gotten 722.6xx internal parts from them that Mercedes didn't sell.

Dan

 

[lightdude95]

Hi guys

Planning to change the K1 and K2 springs this weekend.

I got the following kits:

126 270 44 77 (2X, just to be sure)
126 270 03 35 (K1)
126 270 05 35 (K2)
Several questions:

- Does anyone know the torque spec for the flathead bolts of the cover plates that hold the spring accumulators in their bore?

- I'm planning to combine the new piston of the 126 270 03 35 kit with the springs of the 126 270 44 77 kit for the K1 accumulator, hence the springs in the 126 270 03 35 kit are too weak for the m119.

- following that same train of thought: are the springs supplied with the 126 270 05 35 kit strong enough (K2 accumulator)? Because if not, I'm not sure how I could fit the other 126 270 44 77 kit in there, because the spring setup in the K2 is different from that of the K1 accumulator kit (126 270 03 35)

Thanks in advance!
Sam

 

[lightdude95]

Small update:

Replaced K1 piston and spring (126 270 44 77 springs + the piston from kit 126 270 03 35) successfully.

BUT: K2 piston does not match the one from the 126 270 05 35 kit! Original piston in K2 is 126 277 84 32, the one in the kit is 126 277 85 32 and has a smaller diameter lip on the small side. This can also be seen on @Hakie 's pics on post #22. Not sure how that worked out for him...

The piston that does match the original K2 piston is the one that comes with kit 126 270 04 35. But I'm not sure about the springs in that kit... No idea which springs are the same as the original K2 ones currently in the vb....

 

[lightdude95]

Today I opened up the trans again to change the K2 accumulator parts. I also did some research of my own which I would like to share with all of you.

It seemed that almost nobody knew the EXACT difference between the various spring kits, so I got all of the kits (except the ones for B1) and compared them with each other and also with the springs in my transmission, which is a 722.366, and as the going says: "a picture says more than a thousand words", but a table says more than a million words

BTW: more coils on a spring and thus a longer spring + thin wire diam. = softer spring. Less coils + thicker wire diam. = stiffer spring. You could, of course, balance things out like: long spring with thick wire might be as stiff as a shorter spring with a thin wire. That's how you should interpret this table



Starting from the top:

For the K1, the 126-270-44-77 is by far the stiffest spring pack you can get, stiffer than the factory springs in the transmission. But the kit has no piston included. The 126-270-03-35 has the correct piston for the K1, but the springs are way softer, too soft for a M119 (dixit @gsxr). So I combined the piston of 126-270-03-35 with the spring pack of 126-270-44-77. (In the pic "126-270-03-35 new springs with old piston" I took the pic with the new spring pack, but the old piston because the new one was already installed in the car)

(BTW in case of K1: "medium length spring" = the small spring that goes "into" the big spring)

I couldn't measure the length of the two packed springs of the 126-270-03-35 kit and the ones in the transmission (missing length values marked with an "X"), because I wasn't able to carefully separate the plastic parts holding them together and I didn't want to force/break anything.

Now for the K2 (this is the fun part where nobody in the world seemed to know what or how, not even the dealer or the tranny guys here in Belgium), things seem a bit more complicated.

There are two kits: 126-270-04-35 and 126-270-05-35. The piston in the 126-270-05-35 kit does not match the one in the transmission, given the diameter of the "inner lip" is smaller (19.80mm) than the lip of the piston in the transmission (21.60mm) (see attached pictures). I don't know how @Hakie was able to get good shifts with the 126-270-05-35 piston in his 400E, you can see the difference between the two pistons on post #22 from Hakie himself as well.

Now, on to the good news, the 126-270-04-35 kit does have the correct piston AND the springs are identical to the factory springs in the K2 of the transmission, at least in my case. So it appears that 126-270-04-35 is a 1-on-1 replacement for the K2 accumulator (see attached pictures), which is what I did as well.

For the difference in spring stiffness between the two K2 kits, this is what I felt/measured with my hand:

The long spring in 126-270-05-35 is stiffer than the long one in 126-270-04-35, but the short spring in 126-270-05-35 is softer than the short one in 126-270-04-35.

So long spring of 126-270-05-35 + short spring of 126-270-04-35 would give you the stiffest configuration for K2.

Another point I've read a lot on other fora, was that you can place springs of K1 in K2. That may be possible for other versions of the 722.3XX, but not for the V8 models as far as I know. The coil diameter of the outer, big spring in K1 is 14.3mm (in all kits), while the coil diameter of the big spring of the K2 spring is 12.5mm. There's just no way you can fit a K1 coil pack into the K2 piston. Trust me, I tried.

After replacing those parts, new atf, filter and a new vacuum modulator, tranny shifts nice and firmly. Maybe a tad too firm on 3-4, really bangs into it sometimes, depending on speed and throttle position, but I'll dial the modular in a bit later on, too lazy to get under the car now.

I hope this "research" can help other people in the future and I'm glad that I'm able to share this info with other enthusiasts.

Enjoy your sunday!
Sam

 

[nehuge]

First you need to see what springs are in the FGS now... the factory K1 "upgrade" tends to be a bit firmer than stock, but Superior allows even firmer options if desired. The only way to get a softer 1-2 is via Superior.

The green cylinders for K1 and K2 are available new, IIRC, but you'll need to swap springs around. The new green K1 cylinder comes with springs that are waaaay too soft for an M119 (think they are meant for a 722.4 with a low-torque engine).

Side question - were all the shifts OK with the old VB, and you only have issues with the "new" FGS VB?

I have the 2-3 flare. I did the K1 kit (126-270-44-77) and it helped that flare somewhat (maybe by half) but all other gears are still a bit too firm. I back off on the modulator to make them feel okay and then the 2-3 flares again. I have to set the modulator back to where it was.
Where's the middle ground? What do I do next? Sometimes when I am turning right onto a street and get back into the gas after I straighten out and getting on the throttle the downshift bangs too hard. What to try?

 

[gsxr]

If all other shifts are ok but 2-3 upshift flares, I'd try the Superior kit next. THere are options to go firmer beyond what the factory K1 kit allows.

Now, for downshift flare/bang, that's a different story... can you determine if it's a 4-2 or 3-2 flare/bang? One of my transmissions does this (a no-mile Schmid rebuild, grrrr) and it's really annoying. There's a TSB but the potential fix isn't simple.

 

[jhodg5ck]

Have you checked the integrity of your mod valve? A fresh one never hurt


What fluid are you running?

How many miles on your box?

What all was in the pan when you dropped it the first time?

Jono

 

[nehuge]

So a whole bunch of things:
- Car has 140k on the clock and have had it two years and bought it with maybe 132k on it. M104 ( I know, BUT you guys are SO helpful compared to other forums, argggh)
- Did trans filter, K1, gasket, pan plug crush washer and Dexron III fluid last weekend. Added 4 quarts, went through gears then added the 2.6 or whatever remaining. Aimed infrared gun at pan after driving it around 15 minutes goot and hot and it reads between the two lines on the dipstick (if not closer to the top line when hot). Was like 6.7 quarts or something total. Pan had no metal, even barely any silver paste either. There were two tiny tiny specs (breadcrumb size) but I think it was clutch material as it even didn't stick to a magnet. The fluid was not bright pink but reddish still.
- In case this is vacuum related, I put mityvac on to the line going to the trans modulator and pumped it up, it barely, barely decreased, maybe 5hg per every 10 seconds or something. It shouldn't hold perpetually right?
- Set the factory pressure using the side port according to a chart on another forum that lists out the modulator plastic casing cover (mine is black, others are green, red etc) according to my trans type and year
- For grins I unhooked and capped off the green line (red circle) going to that vacuum switch circled in blue as well as the grey one (rec circle) that goes to the yellow vacuum check valve things also circled in blue like this pic:

Same result.

- The bowden cable has been adjusted to both the right amount of slack per the manuals but also to where the rpm it holds it in to go to the next gear isn't too early nor too late.

- Also for grins, the little nozzle on the intake manifold that the transmission modulator line hooks to via a rubber elbow (has bigger port on one side for the intake nozzle than the other side of the elbow which is for the plastic vacuum line) I put a mityvac on and the vacuum is about 18-19ish. Should that be higher? Or is that port the wrong port to be reading engine vacuum on? There's other places like under the intake manifold by the throttle actuator to measure from, etc just harder to get to.

- And even more grins I took soap water and propane on different days and went to every vacuum fitting I could find (even ones like vac line that goes to map sensor, yellow aircon check valves going into firewall, etc ) and idle didn't change and no soap bubbles.

The 2-3 flare is cut in half with the K1, but when I turn the modulator down (counterclockwise softer to make the 1-2, and 3-4 softer) it makes the 2-3 flare again.

If I take off from a standstill and just barely touch the gas and hold it (like you would through a parking lot center or in a school zone, etc), as it slowly builds the rpms the 1-2 will jolt, the 2-3 feels perfect. 3-4 I obviously never reach when just idling around in slow situations.

If I take off from a standstill with maybe 1/4 to 1/3throttle, the 2200-2500ish range shift and feel from 1-2 happens perfectly, as well as the 2-3, and waiting for the same for 3-4 well, gets me up to about freeway speed when it shifts and it feels good too.

If I take off full throttle, it goes through all gears at the right times and the right shift feel. It's no 500E but the little sucker pulls good.

It's just that barely any throttle thing at low speeds really just snaps your neck from 1-2. Just don't want someone to say "just drive with a heavier foot to avoid this then so it shifts right".... Ya, but.... no.

And that 'coasting in, turning right on a green light without stopping' thing where I moderately get back on the gas when I am coming out of the turn and straightening the wheel will again just 'jolt, boom'. Per GSXR's question, I think it's going from 3 and kicking down to 2 just given the sound and the rpm's. I don't think it's a 2-1 kickdown. I would think I'd have to punch it all the way (click kickdown switch under gas pedal) for it to do a 2-1 but I don't really drive like that.

Questions:
1) what does that thing with that I circled in blue with two electrical wires going to it behind the break booster do anyway?
2) does the square metal vacuum tree on the front of the timing cover that goes over to EGR etc contribute to vacuum issues related to trans quality?
3) What about the yellow check valves on the way to the aircon pods (my pink pods all operate correctly and all hold pressure by the way).

I don't hear hissing anywhere and idle is great, no CEL's and thing is buttery smooth. Temps always barely above 80 on gauge even in stop and go and up hills and in the heat. I love it. I just don't love whiplash.

Opinions everyone?

 

[maw1124]

I'm still with @jhodg5ck ... if that's a 30yo vacuum modulator, I'd replace it "just for grins"... but maybe I'd do that after 500 miles on the new fluid (and filter), at which point I'd go with new fluid again anyway, treating what you just added as "flush fluid". More work, but that's what I would do.

Others?

maw

 

[Kridre]

This issue that you are describing is 100% the same that I had, 2-3 flare when I just cruse but if I floored it all the gears snapped in place like they should. I think that you will need to rebuild at least K1 clutch. Here is how all the gears are applied

1st brake band B2

2nd brake band B1 and B2

3rd K1 clutch brake band B2

4th clutch K1 and K2

So any flare between 2-3 when other gears are fine mean that K1 is at the end of its life. This is just what I discoverer while rebuilding my trany.

I don't know right now if this issue is cured because the car is in pieces, I will probably find this out in 2 years from now. You can see the state of my K1 clutches in my owner's thread.

Edit: or You can just relese the throthle a bit when you are aproching 2-3 shift, after setting other gears the what that You want them to feel. That's how I drove my 124 in the past 7 years.

 

[gsxr]

- In case this is vacuum related, I put mityvac on to the line going to the trans modulator and pumped it up, it barely, barely decreased, maybe 5hg per every 10 seconds or something. It shouldn't hold perpetually right?

Do you mean the vacuum modulator (round thingy) on the driver side of the trans? This should hold vacuum. If you connect a MityVac, it should pump up to 25" Hg or whatever, and hold it. If not - check for leaks. If the modulator is old/original - replace it, they are not expensive.

The 2-3 flare is cut in half with the K1, but when I turn the modulator down (counterclockwise softer to make the 1-2, and 3-4 softer) it makes the 2-3 flare again.

AFTER testing/replacing the modulator, you could still experiment with the Superior kit. They have options to soften the 1-2, make the 2-3 firmer, etc etc. The idea is to compensate for some amount of wear causing different shift firmness at the different shifts (1-2, 2-3, 3-4). It won't fix worn bands or clutches though.

And that 'coasting in, turning right on a green light without stopping' thing where I moderately get back on the gas when I am coming out of the turn and straightening the wheel will again just 'jolt, boom'. Per GSXR's question, I think it's going from 3 and kicking down to 2 just given the sound and the rpm's. I don't think it's a 2-1 kickdown. I would think I'd have to punch it all the way (click kickdown switch under gas pedal) for it to do a 2-1 but I don't really drive like that.

Pay attention to the gear it is in before you start slowing for the turn, and the speed during the turn, before pressing on the accelerator. If you find it's a 4-2 downshift and 15-20mph during the turn, it sounds a LOT like the issue I encountered, and there is a factory TSB which explains in more detail.

1) what does that thing with that I circled in blue with two electrical wires going to it behind the break booster do anyway?

Cold upshift delay solenoid, typically energized for a short time after a cold start, to speed up catalyst heating. If disconnected/disabled (even the vacuum portion) it will eventually trigger a CEL. But it won't affect shifts at operating temp. And when cold it's just pulling more on the Bowden to increase shift RPM.

2) does the square metal vacuum tree on the front of the timing cover that goes over to EGR etc contribute to vacuum issues related to trans quality?

Only if there's a leak anywhere in the vac system, but the modulator vac tube should connect directly to the intake manifold? This reduces the effect of other vac leaks, assuming manifold vacuum is normal-ish.

3) What about the yellow check valves on the way to the aircon pods (my pink pods all operate correctly and all hold pressure by the way).

Those should be mostly irrelevant as well, for the reasons explained above.

Has there ever been any sign of abnormal debris in the trans pan, particularly chunks of friction material? If so, as Kridre mentioned above, you may have bigger issues. If not, there's still hope for improvement with the modulator / springs. And a VB cleanout.

Also, has the trans always shifted like this since you bought the car? If not, when did it start? Was it all at once, or gradual? Etc.

 

[nehuge]

Do you mean the vacuum modulator (round thingy) on the driver side of the trans? This should hold vacuum. If you connect a MityVac, it should pump up to 25" Hg or whatever, and hold it. If not - check for leaks. If the modulator is old/original - replace it, they are not expensive.

Yes, vacuum modulator. It should hold vacuum indefinitely without decreasing at all?

Pay attention to the gear it is in before you start slowing for the turn, and the speed during the turn, before pressing on the accelerator. If you find it's a 4-2 downshift and 15-20mph during the turn, it sounds a LOT like the issue I encountered, and there is a factory TSB which explains in more detail.

Ok

Cold upshift delay solenoid, typically energized for a short time after a cold start, to speed up catalyst heating. If disconnected/disabled (even the vacuum portion) it will eventually trigger a CEL. But it won't affect shifts at operating temp. And when cold it's just pulling more on the Bowden to increase shift RPM.

Ok

Only if there's a leak anywhere in the vac system, but the modulator vac tube should connect directly to the intake manifold? This reduces the effect of other vac leaks, assuming manifold vacuum is normal-ish.

It is directly to the manifold. Is the vacuum I read at the port enough?

Also, has the trans always shifted like this since you bought the car? If not, when did it start? Was it all at once, or gradual? Etc.

No debris at all, two breadcrumb specks of clutch that weren't magnetic. It's done this ever since I had the car. The diff mounts, trans mount, motor mount, flex disc, carrier barrier all new too.

 

[gsxr]

Yes, vacuum modulator. It should hold vacuum indefinitely without decreasing at all?

IIRC, yes, but I'd need to confirm on one of my cars. But I'd expect either zero leakdown (decreasing vacuum), or very very slow leakdown.

It is directly to the manifold. Is the vacuum I read at the port enough?

A "T" fitting in the line to the modulator would be ideal, but otherwise one of the other ports at the manifold should suffice for general vacuum readings.

No debris at all, two breadcrumb specks of clutch that weren't magnetic. It's done this ever since I had the car. The diff mounts, trans mount, motor mount, flex disc, carrier barrier all new too.

OK, so it wasn't something that developed over time. Bummer you have no history. For grins you can compare the serial number on the trans with the datacard and figure out if the trans is original, or if it was replaced by the PO. Wouldn't be the first time there was a bum rebuild.

 

[IslandMon]

I purchased and installed a rebuilt transmission from Sun Valley last summer, and installed a FGS valve body . Overall the FGS is great, and new tranny feels better than the old. I messed with the bowden cable and modulator quite a bit to get the tranny to shift as well as it is now.

I have a few shift issues that I was able to make a little better with modulator adjustments, but am hoping to make the shifts a little better with the Superior spring kit.

Before I dive in and start replacing K1 , K2 and B1 springs, I figured it would be a good idea to check with the group here to see if anyone has recommendations based on my symptoms.

First: the 1-> 2 shift is rather harsh, at varying throttle positions, but most noticeable at light throttle. It certainly is something I could live with, but would be nicer if it was a little softer.

Second: the 2->3 shift is a bit soft.

Based on what I have read on the forum, the K1 may help the 2-3 shift, and the new B1 spring may soften the 1-2 shift.
I am running redline d4 high temp synthetic ATF. I also purchased tve OEM k1 kit from naperville, not sure if Superior or OEM is better than the other for K1 upgrade.

Last question: is it worth replacing the cylindrical plastic pieces in K1 and K2 while I’m in there? I assume they last the life of the tranny, but not sure if the seals are replaceable.

Similar to @gsxr in a thread I found on Peachparts, nearly 5 years later I finally had time to pull the superior kit off the shelf...

I drained and removed the pan and was able to easily drain the TC without having to remove the flieben crossover pipe, nice straight shot at the bolt. I used the tinfoil method to create a nice slide into the drain pan.

As everyone mentions, the directions were confusing so I did a lot of reading across various forums to get a consensus on the best way to install. My main issues before the kit were a rough 1-2 shift at proper RPM, and a flaring 2-3.

I chose to follow Superior's guidance and replace nearly all of the springs per the instructions. I did somehow miss inserting one of the old springs into the red in step 5, but I don't think there were any consequences. When done I refilled with ~8.5 qts of redline D4 since I had removed the valve body and let things drip overnight.

Process

Step 1 - removed VB and separated. Watch out for the ball that sits atop the spring, mine stuck to the separator plate when I lifted the lower half of the VB off, and could have easily rolled away into oblivion.

Step 2 - Firming up the 2-3 and 3-4 shifts - Replaced the K1 and K2 accumulator control valve springs with the white springs. The pic shows the two "gates" that need to be pulled so that the springs can be accessed.


Step 3 - Normal firm shift (?) - Replaced the 2 spring train and plastic clip/ends in the K1 accumulator with the Purple spring. The Blue spring would not fit inside the plunger on the K2 side, so I followed the instructions for the "late 722.3" and removed the 2 springs from the k2 accumulator and installed the Red spring. The 2 new short Blue springs were not used, and it seemed they were not to be used with the new Purple and Red springs in K1 and K2.


Step 4 - To firm up the 2-3 shift even more - Completed in step 3 - Replaced the springs and plastic clips/ends with the Purple spring

Step 5 - To firm up the 3-4 shift even more - Didn't do this step, but wondering if I should have added the original inner spring from the K2 accumulator into the new K2 Red spring installed in step 3. There doesn't seem to be any issue though.

Step 6 - For softer 1-2 shift - Replaced the B1 accumulator control valve spring with the longer, plain finish one.


Step 7 - For softer 1-2 shift - Replaced the B1 accumulator spring train with the Orange spring.


Step 8 - For even softer 1-2 - Replace the 2 spring train on the k2 side with the Light Blue spring.



Results
1-2 shift is no longer hard, but now shifts at 3500 rpm, much later than before/usual. Shifts firm and smooth but too late.
2-3 flare is gone and shift is firm and smooth. There were some occasional blips/ loss of engagement, that I think went away after a few hot laps/topping off fluid.
3-4 - firm and smooth no issues
WOT Kickdown from standstill - quick takeoff/great torque, gains good speed then hits redline rev limiter, doesn't upshift... I have to ease off gas to get it to stop bouncing off the limiter and shift

Overall reaction
The car feels more aggressive and seems better than it was. Now I just need to sort out the late 1-2 shift and lack of 1-2 shift at kickdown and I'll be able to call this a definitive major improvement

Next steps? - need 1-2 shift to happen sooner, and to resolve lack of 1-2 upshift at WOT kickdown.
After a lot more reading, It looks like I may need to turn the control valve full throttle set screw on the side of the valve body to get the transmission to shift before it hits the limiter. The manual Dave posted says 1-2 turns for this symptom. Does anyone have any experience adjusting this screw? Here is a link to the FSM procedure, thanks @gsxr ! edit: replaced link with correct one

I'm feeling lucky that I'm seemingly so close to having the box sorted with only 1 drop of the pan (vs the 8 that I've read others having to do to get things right) and don't want to have to drop the pan more than I need to to adjust this set screw. I'm still on the fence about if I'm going to try to drain fluid into a brand new pan for reuse, or if I'm going to have Amazon on standby for 8 quart redline deliveries every time i drop the pan...Really hoping I don't have to drop the pan too many times

I already tried adjusting the bowden cable, which had its arrows aligning perfectly with throttle linkage before I made some tweaks, marking everything with a paint marker before so I could easily reset to "baseline". Shortening the linkage rod for the Bowden seemed to get the 1-2 shift down to 3000 RPM, still too high, but the lack of upshift at kickdown issue remained. This adjustment set the arrows 4-5 mm apart, but no negative change to shifting, so I'm inclined to set them back into alignment and try the adjustment screw on the VB.

Any and all input or tips are welcome. I am going to sleep on this for a bit before any next moves as I already feel pretty lucky thus far!

 

[jhodg5ck]

Nice write up!


Last time I had to play with that set screw was years ago, but it did remedy a box that kept slamming the limiter even with the bowden cable slacked out..

Why wouldn't you catch the fluid in a Clean container and re-use?? No reason not to IME.


You'll get real good at dropping the pan quickly by the 4th/5th time...

I'd try the screw a turn or two. See how she does.

Jono

 

[IslandMon]

I'd try the screw a turn or two. See how she does.

Thanks for the tip @jhodg5ck . I’ll try one turn to start. Do you have any experience with step 5, reusing the short spring inside the new Red spring?

Why wouldn't you catch the fluid in a Clean container and re-use?? No reason not to IME.

Was on the fence about it, but will take your advice and catch with a new drain pan & reuse, just ordered some paint filters as an extra precaution.

Thanks!

 

[jhodg5ck]

Thanks for the tip @jhodg5ck . I’ll try one turn to start. Do you have any experience with step 5, reusing the short spring inside the new Red spring?


Was on the fence about it, but will take your advice and catch with a new drain pan & reuse, just ordered some paint filters as an extra precaution.

Thanks!

I've stacked springs, yes...I've even stacked some in places it didn't call for when I'm building a Bang-Screech box

....i was gonna say if you wanna be super safe some paint filters will do the trick.. gold star for you

 

[gsxr]

+1 on draining into a clean gallon jug. As long as the container is clean, and the pan is super clean so no dirt enters the jug, it's fine to re-use. I buy gallon jugs of ATF (not quart bottles) and save a couple of the clean jugs for draining if needed.

For the shift issues - there's a phone number on the instructions, I'd call Superior and talk to them before doing anything else.

 

[IslandMon]

For the shift issues - there's a phone number on the instructions, I'd call Superior and talk to them before doing anything else.

Superior says to disconnect the bowden cable and report back, so I'll try that one night this week and report back. I have a feeling that the full throttle valve screw is the only fix for the WOT 1-2 upshift.

 

[gsxr]

Do not attempt any WOT pulls with the Bowden cable disconnected. Bad things happen.

For the 1-2 upshift hitting the rev limiter, make sure the fluid level is at MAX when hot. Also, make sure the transmission isn't cold or cool when testing. I've had the rev limiter problem at 1-2 WOT if the trans was not warm and fluid level was below MAX.

The WOT upshifts are a combination of the kickdown solenoid (power is interrupted by the LH module), the Bowden cable, and the setscrew on the VB. It's odd this problem only occurred after installing the Superior springs.

 

[IslandMon]

For the 1-2 upshift hitting the rev limiter, make sure the fluid level is at MAX when hot. Also, make sure the transmission isn't cold or cool when testing. I've had the rev limiter problem at 1-2 WOT if the trans was not warm and fluid level was below MAX.

I will certainly take a closer look at this before disconnecting the Bowden cable, once the rain stops around here, as a little more fluid may be needed to get it to the MAX line. I have put in about 8.6-8.7 qts so far and was hesitant to add more, but there probably is another 2 mm of dipstick showing before the MAX line. I did originally let the trans and TC drain overnight after the VB was removed, with the car level, so the majority must have drained out.

I may have not done any WOT pulls since I put the new trans in in 2019, so it may have been this way since I installed the FGS valve body with the new trans.

Thanks Dave

 

[IslandMon]

Topped off fluid but the WOT no 1-2 upshift problem persists. Still a late 1-2 shift and a slight occasional flare with the 2-3.

Disconnected the bowden cable and there was no difference to shifting driving up to 40 mph. I assumed the shifting would be completely different and worse.

I am going to drop the plan to try 1 or 2 turns on the full throttle valve screw to see if I can solve the WOT shift, and install the smaller spring inside the larger one in step 5 to try to get rid of the 2-3 flare.