FYI Sun Valley Transmission - Additive recommendation

[Alphasud40]

I have 2 034 cars that have sticky valves in the valve bodies. One of them the 92 400E will randomly miss the 1-2 up shift only when the kick down solenoid is activated. The other the 94 E420 will randomly neutral out after coming to a complete stop. Shifting into reverse and then back into drive will cure that issue.

So I contacted Sun Valley asking if they sold rebuilt valve bodies or if they would rebuild if I sent mine. Currently they do not offer any components for sale. Only rebuilt units. Also they are so backed up with work so if you need to have a transmission rebuilt there might be extended down time if they don’t have one ready to go.

He did however recommend an additive that has worked wonders for them for random or intermittent issues that I described above. The product is called Prolong Transmission Additive and you can find it on Amazon and possibly Walmart. So if you are experiencing strange intermittent issues with your transmission service it with new fluid and add a bottle of Prolong.

https://www.amazon.com/Prolong-Super-Lubricants-PSL15000-Transmission/dp/B001DKV5H8?

 

[gsxr]

Great info! Have you tried Prolong yet?

Also - are you going to have them rebuild one of your VB's despite the long wait? Or try it yourself, disassembling & cleaning everything?

 

[gsxr]

I have 2 034 cars that have sticky valves in the valve bodies. One of them the 92 400E will randomly miss the 1-2 up shift only when the kick down solenoid is activated.

Could you elaborate on this? Do you mean at WOT, the transmission does not shift from 1 to 2, and the engine hits the rev limiter?

 

[Alphasud40]

I ordered the Prolong today so it will be a few weeks until I can report back on my experience. The 92 400E will randomly miss a downshift when the kick down solenoid is activated like pulling into traffic and needing more acceleration prompting a kick down. Kind of hard to describe but it’s a harsh shift or jerk followed by total loss of engagement causing engine to redline. The 94 just goes into neutral during a normal 2-1 downshift after slowing to a stop.
I also plan in the future to remove the 94 valve body and going through all the valves and polishing the valve bores with bore brushes. I don’t want to risk doing this on the 92 that I don’t own. Sun Valley turned me down on a valve body rebuild or exchange so it would have to be another company and I’m leery about doing that unless someone else has a good rebuilder.

 

[gsxr]

I ordered the Prolong today so it will be a few weeks until I can report back on my experience. The 92 400E will randomly miss a downshift when the kick down solenoid is activated like pulling into traffic and needing more acceleration prompting a kick down. Kind of hard to describe but it’s a harsh shift or jerk followed by total loss of engagement causing engine to redline.

Ohhhhh. That ain't right.

The 94 just goes into neutral during a normal 2-1 downshift after slowing to a stop.

That's also weird!

I also plan in the future to remove the 94 valve body and going through all the valves and polishing the valve bores with bore brushes. I don’t want to risk doing this on the 92 that I don’t own. Sun Valley turned me down on a valve body rebuild or exchange so it would have to be another company and I’m leery about doing that unless someone else has a good rebuilder.

 

[nocfn]

I have the E420 Valve body installed in my car and I thought about removing it when I do my filter change service this winter. I think I would rather shift the gears as needed to match the experience in the w126 - ON DEMAND so to speak. Just saying...

I too ordered the stuff, we shall see if and when I need to use it.

 

[natejgreene9871]

I've bought 3 transmissions from sun valley, they really are worth the wait. They upgrade to stiffer reverse clutch springs, everything is tested, vacuum modulator adjusted, etc. Just install and go. I really can't say enough good things about their work.

 

[8899]

I just recently sourced a 722.6 transmission for my G55 from Sun Valley. All in cost including round-trip shipping (East Coast) was $3,100.00. I've put a couple hundred miles on it since install and it works fine. Marc was very easy to deal with as well.

 

[8899]

For additional information on why I had to replace the transmission on the G55:

::: icap.clubgwagen.com - validate your humanity :::

clubgwagen.com

Long story short - the torque converter was failing. See post #66.

 

[Joncf]

For additional information on why I had to replace the transmission on the G55:

::: icap.clubgwagen.com - validate your humanity :::

clubgwagen.com

Long story short - the torque converter was failing. See post #66.

Im not sure if you’ve done any further diagnostics or if you’re already aware of this, but a worn torque converter lockup solenoid is a very common cause of the symptoms you experienced on the 722.6. It’s called TC “shudder,” and is easily replaced by dropping the valve body. It sits on the conductor plate with the rest of the solenoids above the valve body. Definitely a good idea to just replace the conductor plate as well, since it’s basically a wear item on this transmission. This is a well known problem and is usually fixed with this repair and fresh fluid/filter. It would be somewhat rare that your torque converter was outright failing… and even then you wouldn’t necessarily need a new transmission. There are people who have replaced their “failing” torque converters due to the “shudder,” without having solved the problem, because it was not the cause... the solenoid was. This lockup solenoid is known to wear because the 722.6 converter locks in every forward gear, meaning it’s constantly opening and closing. If you have access to STAR, it’s possibly to disable TC lockup temporarily, and perform other actuations to confirm that it is actually the culprit. If the transmission is significantly worn or has high mileage, then I could see why you’ve chosen to just replace the whole unit for “peace of mind.” However, replacement of the solenoid is very easy and straightforward… and might solve the problem. Some people also replace the overlap control valve sleeves in the valve body in hopes of curing the “shudder,” but you’d likely have other shifting issues if those bores in the valve body were worn.

Edit: I just saw that you’ve already completed the transmission replacement, so I guess we will never know. I’m glad everything turned out alright.

 

[gsxr]

Many years ago I experienced a converter shudder on two different W210's with 722.6 transmission. It was almost exclusively when cruising at ~25mph. I modified the valve body to force the piston into the position such that the converter NEVER locked up. Worked like a charm, other than a persistent fault code on the EGS (TCU) module which I ignored.

 

[Joncf]

Many years ago I experienced a converter shudder on two different W210's with 722.6 transmission. It was almost exclusively when cruising at ~25mph. I modified the valve body to force the piston into the position such that the converter NEVER locked up. Worked like a charm, other than a persistent fault code on the EGS (TCU) module which I ignored.

Yes, I’ve heard of people doing this by drilling a hole in valve body. I’m not sure if it causes further transmission issues due to never locking up, but I would rather just replace the valve body altogether to fix the problem. Remember, without lockup, there is theoretically a lot more slippage and heat generation within the transmission. Either way, it’s great to know that it works and I’m sure the transmission becomes overall smoother!

 

[gsxr]

Remember, without lockup, there is theoretically a lot more slippage and heat generation within the transmission. Either way, it’s great to know that it works and I’m sure the transmission becomes overall smoother!

I believe this is urban legend. All previous 722.x converters had no lockup, so other than losing a tiny (tiny!) bit of efficiency, there's zero downside. There was no additional heat and no slippage in the transmission itself, just the normal converter slippage without the clutches locked.

 

[yevgenievich]

I believe this is urban legend. All 722.x previous converters had no lockup, so other than losing a tiny (tiny!) bit of efficiency, there's zero downside. There was no additional heat and no slippage in the transmission itself, just the normal converter slippage without the clutches locked.

Depends on transmission design and coolers in the system. Most are likely fine, but GM had issues with earlier 700r4 transmissions due to lube circuit being compromised in 4th gear without lock up working, which came up when people were disabling lockup and running od.

 

[emerydc8]

Depends on transmission design and coolers in the system. Most are likely fine, but GM had issues with earlier 700r4 transmissions due to lube circuit being compromised in 4th gear without lock up working, which came up when people were disabling lockup and running od.

I have a 700R4 (4L60E) in my 1992 Camaro Z28 and having no lockup significantly raised coolant temperatures. I went a year knowing the lockup solenoid was not working before I finally got around to replacing it. The coolant temperature was highest on the freeway at 85-90 where it should have always been locked unless accelerating. I've always wondered how much slipping (if any) goes on in the 722.3xx TQs at cruising speed. By the looks of @gsxr's post it sounds like very little.

 

[gsxr]

722.6 converter slippage at cruising speed is negligible. The ATF temperature takes FOREVER to get up to 80C, even in 90F+ ambient summer temps... like, 30-45 minutes of driving. And that's with the converter lockup disabled. Definitely no concerns about 722.6 slippage and increased temps. Sounds like GM and maybe other marques did have issues, but those are different designs.

 

[yevgenievich]

Back between 80 and 86 700r4 transmissions would burn up due to lube circuit being blocked off if tcc was disabled in overdrive. I think most manufacturers took that as a study case and made appropriate designs since then.

 

[Jouser]

modulator adjusted, etc. Just install and go. I really can't say eno

I've bought 3 transmissions from sun valley, they really are worth the wait. They upgrade to stiffer reverse clutch springs, everything is tested, vacuum modulator adjusted, etc. Just install and go. I really can't say enough good things about their work

I've bought 3 transmissions from sun valley, they really are worth the wait. They upgrade to stiffer reverse clutch springs, everything is tested, vacuum modulator adjusted, etc. Just install and go. I really can't say enough good things about their work.

Are the stiffer reverse clutch springs unique to SV only or do other recommended MBZ tranny rebuild companies use these? On my new-to-me wagon, I notice the P to R transition is very quick, and you can hear and feel a small (but comfortable) thud - this is unlike my other 3 cars on their original transmissions where there is some delay, but there is no "thud" into reverse. This tranny was rebuilt by Peter Schmid Transmissions Mzf Inc in Burlingame CA in 2022.

P.S. I have felt this quick reverse thud on other Classic MBZ cars with known-rebuilt transmissions. Example: 1994 SL600 V12

 

[natejgreene9871]

Are the stiffer reverse clutch springs unique to SV only or do other recommended MBZ tranny rebuild companies use these? On my new-to-me wagon, I notice the P to R transition is very quick, and you can hear and feel a small (but comfortable) thud - this is unlike my other 3 cars on their original transmissions where there is some delay, but there is no "thud" into reverse. This tranny was rebuilt by Peter Schmid Transmissions Mzf Inc in Burlingame CA in 2022.

P.S. I have felt this quick reverse thud on other Classic MBZ cars with known-rebuilt transmissions. Example: 1994 SL600 V12

I may be wrong on the details here but this is my understanding. Sometime around 1989 Mercedes added stiffer springs to the reverse clutch pack of their transmissions. The intent was to make shifting into reverse smoother with less jerk/shudder to please the customer. The car would more gradually engage the friction disk rather than quickly snapping into gear like the older cars. This was fine when new, but over time this caused increased wear in the reverse friction disk.

Additionally reverse issues begin to occur on higher mileage transmissions. As the transmission wears, there is more pressure leakage at all the internal rubber clutch pack seals. The reverse gear, with its beefed up springs, begins to struggle to engage. The hydraulic pressure has to overcome the force of the reverse springs to engage reverse.

In summary, Mercedes vehicles beginning sometime in the late 80’s through the 90’s are susceptible to reverse gear failure at higher mileage (let’s say 120k+).

Often times the transmission is totally fine in forward gears but you loose reverse. Anytime you are looking to buy a car from this era, you should put the vehicle in reverse and count how many seconds it takes to engage. Once it’s starts to take 2 or 3 seconds to engage, the reverse gear it is about to go out.

My understanding is that Sun valley backdates the springs to the early 80’s setup. I think they install fewer springs to prevent this failure of reverse. It shifts into reverse more abruptly but lasts longer.

I learned all about this mess when I bought my 1993 190e. I lost reverse within 24 hrs of buying the car and went down the rabbit hole. Ended up buying a rebuilt from SV.

Here are some photos of reverse gear springs/piston out of a w123 to help visualize what I am talking about. Notice all the little springs and round metal plate they press against.

 

[gsxr]

Nate's explanation is correct. The "fix" is to reduce the number of springs from 20 down to 16 or 15 by removing 5th or 4th spring, so there is an even distribution of springs. This allows the reverse piston to engage more firmly / quickly and extends clutch pack lifespan.

 

[natejgreene9871]

On the bright side of things, i actually look for cars for sale that have lost reverse. It’s a good bargaining chip. If you can pull the trans yourself, the reverse clutch is the first one in the transmission so it’s not terribly hard to fix. This is one of my favorite YouTube channels and where he fixes reverse from a r129

 

[luckymike]

It's my turn to use Sun Valley. After years of slow-engaging reverse, it finally quit working.

I"m driving down from the SF Bay Area this Friday and will be dropping the car off on Monday. Marc is rebuilding mine so the numbers will still match.

Wish me luck. It's VERY hard to let someone else work on my car.

 

[nocfn]

At least you will be there. My local shop did both of my car's rebuilds. They too used the same, resident externals to make it like it never even happened. At the time, all MB parts were used as well. I think you will very happy with the outcome.

 

[natejgreene9871]

It's my turn to use Sun Valley. After years of slow-engaging reverse, it finally quit working.

I"m driving down from the SF Bay Area this Friday and will be dropping the car off on Monday. Marc is rebuilding mine so the numbers will still match.

Wish me luck. It's VERY hard to let someone else work on my car.

How many miles are on the car out of curiosity?

 

[luckymike]

At least you will be there. My local shop did both of my car's rebuilds. They too used the same, resident externals to make it like it never even happened. At the time, all MB parts were used as well. I think you will very happy with the outcome.

Thanks. I sure hope so.

How many miles are on the car out of curiosity?

266,260

 

[natejgreene9871]

Thanks. I sure hope so.

266,260

Oh wow you got good mileage out of that transmission. You must have changed the fluid a lot.

 

[luckymike]

Oh wow you got good mileage out of that transmission. You must have changed the fluid a lot.

I did when we first got the car. Then once reverse started taking a long time to engage, we drove it very carefully, never stressing reverse.

 

[natejgreene9871]

I did when we first got the car. Then once reverse started taking a long time to engage, we drove it very carefully, never stressing reverse.

Seems like a crap shoot. Reverse on my 190e failed at 190,000 and 400e at 125,000 but they had questionable fluid change history

 

[luckymike]

Well, it's done. Didn't go perfectly smoothly but all was handled with class and professionalism.

When I picked the car up this morning, I took it for a test drive. It was clearly lacking in power. Marc took it for a drive and immediately concurred. We put the car up on the rack and tested overload switch and O2 sensor. Both good.

Marc instructed his son, who has worked with him for many years, to pull the valve body. After investigating, they discovered one check ball was in the wrong hole. That fixed it and Marc apologized for the error and thanked me for my patience. What a pleasure it was to work with him.

It was very hard for me to turn my car over to a stranger since I usually do everything myself. But Marc made it very easy which really meant a lot to me.

One thing I really like is the speed with which drive engages. It's almost the speed of thought! I mean it's crazy fast. Reverse comes along pretty quickly without any harsh engagement. Wide open throttle is a pleasure, at least for the first two gears. Have to find an appropriate road to test the upper limit shifts.

I'll drive the car for a couple weeks before deciding to adjust anything but so far I'm not crazy about how soon after a stop the 1-2 shift happens. Other than that things feel pretty good. And the two-year warranty is confidence-inspiring.

On my way back to the hotel, I stopped to visit our own TerryA. What a great guy. I caught him on his way to a car show to display his very pretty 500e.

 

[nocfn]

Hey fellas! Great picture!!!

Mike I bet you will enjoy the differences in no time. You were (like me) so used to a set of ways that you must have felt viscerally - that it messes with your senses. I experienced it both in the 126 and the 124 after rebuilds. But, you will know if its still wrong after 30 days.

 

[emerydc8]

Great pic! Enjoy the new transmission Mike!

 

[gsxr]

I'll drive the car for a couple weeks before deciding to adjust anything but so far I'm not crazy about how soon after a stop the 1-2 shift happens. Other than that things feel pretty good. And the two-year warranty is confidence-inspiring.

Mike, adjust the horizontal throttle linkage rod directly behind the airbox to change the shift points higher or lower. Try 1-2mm at a time for coarse adjustments, <1mm for fine adjustments. It's fairly sensitive. This affects all shifts / all gears, up & down. If only one particular shift is "wrong', you'll need to talk to Marc and see what he recommends.

If any upshifts have a hint of flare, you can tweak the vacuum modulator 0.5-1.0 turn CW to make them firmer. Again, this affects all shifts. If a particular shift is not quite right, this can usually be tweaked with different springs in the valvebody.

 

[TerryA]

Well, it's done. Didn't go perfectly smoothly but all was handled with class and professionalism.

When I picked the car up this morning, I took it for a test drive. It was clearly lacking in power. Marc took it for a drive and immediately concurred. We put the car up on the rack and tested overload switch and O2 sensor. Both good.

Marc instructed his son, who has worked with him for many years, to pull the valve body. After investigating, they discovered one check ball was in the wrong hole. That fixed it and Marc apologized for the error and thanked me for my patience. What a pleasure it was to work with him.

It was very hard for me to turn my car over to a stranger since I usually do everything myself. But Marc made it very easy which really meant a lot to me.

One thing I really like is the speed with which drive engages. It's almost the speed of thought! I mean it's crazy fast. Reverse comes along pretty quickly without any harsh engagement. Wide open throttle is a pleasure, at least for the first two gears. Have to find an appropriate road to test the upper limit shifts.

I'll drive the car for a couple weeks before deciding to adjust anything but so far I'm not crazy about how soon after a stop the 1-2 shift happens. Other than that things feel pretty good. And the two-year warranty is confidence-inspiring.

On my way back to the hotel, I stopped to visit our own TerryA. What a great guy. I caught him on his way to a car show to display his very pretty 500e.

@luckymike,
It was nice to see you again Mike! I hope that new trans performs up to spec. That long drive home will tell the story. Have safe drive home.

 

[gerryvz]

I'm glad you had a good experience with Sun Valley. Marc is a true whiz with the 722.3. Somewhere on the forum I posted a thread about a partial day I spent with Marc and in and around their facility, together with a lot of photos. This was many years ago. I'm assuming they are still in the same building.



I found the thread, here:

A visit to Sun Valley Transmission, Van Nuys, CA | Transmission and Driveline

LINK TO THEIR WEBSITE: http://mercedestransmission.com/ On Friday morning, I visited Sun Valley Mercedes Transmission, in Van Nuys, CA. This is a MB transmission rebuilding specialist in the San Fernando Valley. They are the ones who built me a new transmission that is going into my wife's...

www.500eboard.co

 

[gerryvz]

On my way back to the hotel, I stopped to visit our own TerryA. What a great guy. I caught him on his way to a car show to display his very pretty 500e.

That's a nice photo. We need to do another SoCal E500E gathering. The last one was what, in 2015 I think? It was a while ago. I would definitely come out. I can do a business trip to visit my company's headquarters in Irvine for a few days......

 

[luckymike]

Trans rebuild update:

Unfortunately, I get about a 4 inch puddle of tranny fluid overnight on the ground. It's under the right side of the transmission, about 2/3 of the way back

Since I'm prepping this car for a five-week road trip at the end of April,I've sent an email off to Marc for ideas. Don't really have time to drive it the 6 1/2 hours down to him, so I hope it's an easy fix.

 

[gerryvz]

UGH. Sad to hear this.

With a leak that big, perhaps it could be from the pan gasket. Hopefully the pan didn't get bent/tweaked on install.

That said, try to clean that side of the transmission off with brake cleaner, and drive the car say 20 miles, and see where the leak comes back from.

 

[nocfn]

SHITE! I know they (you) will get it worked out. We all relate to that sinking feeling Mike..... but it may be something simple.

 

[gsxr]

Gerry is correct - you'll need to identify the source, which will require cleaning all ATF, and seeing where it reappears. Start by seeing what areas are wet with ATF and which are completely dry, that will help eliminate possibilities.

For any locations wet with ATF, stuff paper towels around potential leak points (dipstick O-ring, Bowden O-ring, B1 cover, B2 cover, kickdown solenoid, etc) after cleaning & drying the area. With a leak that large you may not need to drive the car, just wait a few hours and you may see a visible drip from the offending location/seal.

 

[TerryA]

@luckymike,
Mike, sorry to hear that you’ve got a leak issue w/ your new rebuild. Maybe when they inspected the valve body they tweaked the oil pan on in a rush to fix the misplaced ball in the valve body.

I hope for you it’s an easy fix. On the upside you got home OK

Take Care

 

[luckymike]

@TerryA Thanks, I was thinking the same. Fingers crossed.

By the way, here's what reverse looks like after it fails.

 

[nocfn]

I found that for me, when I messed up on my sequence of the torque down, and clearly cinched it wrong to get a little weeping, no matter what I did. After a few "moments" I just decided to drain, use new seal and left my phone off while I paid attention to detail - sequence and torque specificity. That cured it for me. Lesson learned on one use seal (gasket)

 

[maw1124]

I've observed that not too many people use that sequencing thing. My Sarasota guys, religiously, which is where I learned it. Everyone else, not so much. I’m hoping @luckymike just has an improperly installed gasket as well.

maw

 

[nocfn]

OH and a light smear of blue halomar works very well both sides of the seal. Both on the 126 and 124 pan gasket (seal)

 

[luckymike]

LEAK FIXED.

It was the drain plug. A grungy old drain plug had been installed. It was covered with thick black paint. Gross. Not on my brand new trans! I personally had installed a new plug when I last changed fluid so I wonder why they didn't at least use mine. It's like they pulled one out of a used bin. I installed a new plug and washer and all is well again.

I also noticed the two side pan bolts were fairly loose and the ones at the four corners seemed over-torqued. This was also disappointing.

If Marc and his crew weren't such great guys, based on my brief interactions with them, the $3,750 bill would be harder to swallow after these disappointing details. Still isn't shifting as nicely as before the rebuild but I'll let things settle in before messing with that.

 

[landspeed]

Going back to the original topic, has anyone felt any improvements from using the Prolong additive? I know my transmission is worn, and needs a rebuild, but it also has some funky shifting characteristics, too. If an additive can "improve" some characteristics, it would be worth it to me, while I prepare for a trans rebuild.

 

[maw1124]

I forgot to ATDQ on this one ("Answer the damned question")...

When I got my Sun Valley rebuild, I asked Marc about additives and I recall vividly what he told me: "Marcus, it's not what goes into these transmissions that concerns me, it's what doesn't come out. Mercedes seals don't always like those additives, and once you put it in you have no control over how much stays behind and ruins the factory internal seals."

At the time it was whatever BG transmission fluid du jour that I was asking about, because I generally like BG products (or at least until then I did). Ever since then I stay away from most additives.

Good clean fuel, oil, transmission and hydraulic fluid for me please. You know, the stuff the car was designed for and pretty much only that. I'll test stuff out on the Allroad (because it's the rolling dead anyway) but not the Benzes.

maw

 

[landspeed]

I forgot to ATDQ on this one ("Answer the damned question")...

When I got my Sun Valley rebuild, I asked Marc about additives and I recall vividly what he told me: "Marcus, it's not what goes into these transmissions that concerns me, it's what doesn't come out. Mercedes seals don't always like those additives, and once you put it in you have no control over how much stays behind and ruins the factory internal seals."

At the time it was whatever BG transmission fluid du jour that I was asking about, because I generally like BG products (or at least until then I did). Ever since then I stay away from most additives.

Good clean fuel, oil, transmission and hydraulic fluid for me please. You know, the stuff the car was designed for and pretty much only that. I'll test stuff out on the Allroad (because it's the rolling dead anyway) but not the Benzes.

maw

That makes sense. However, Sun Valley specifically endorsed the Prolong additive. That's why I'm asking about feedback on this additive.

 

[maw1124]

That makes sense. However, Sun Valley specifically endorsed the Prolong additive. That's why I'm asking about feedback on this additive.

Yes... Marc was advising me about a caring long term for a NEWLY REBUILT transmission, not for prolonging one that might be on its way out anyway.

maw