B1 722.3 cover - seal change help please?

[Duh_Vinci]

Cheers all!


In the project car, 1995 SL500 B1 Seal is leaking, I manged to remove the assembly w/o dropping transmission, but for the life of me, this B1 cover, the white seal

Needs to be re-installed, can't figure out how to take these pieces apart,

I can see a clip there, I'm sure that is what's holding these together, but I don't want to screw it up, how do you take these apart???


Thanks for your help in advance!


Regards,
D

 

[Duh_Vinci]

Ok, so I figured it out, the bastard clip:



Not sure if there is a special tool, but I had to firmly pull two plates apart to gain access to the clip...



Two small screw drivers on each side to pry it up, and it released the shaft of the inner plate enough to separate these two

Groove of the shaft...



Now, I know our tunnels are different, but if it helps anyone with R129, this is the "fancy" tool I fabricated, worked fine, turn buckle, replaced the screw on one end, so it fits flush into the B1 piston cover and 2x4 notched and height from the floor to the upper end of the tunnel to keep threaded loop of buckle from turning



New fluids (again), drained the converter again, this has the be the cleanest lube this tranny been since new!

Tomorrow - will see, but there SHOULD NOT be any more leaks, cleaned everything, sprayed and wiped everything bone dry, large tray with white cardboard under the car for the night.... Kinda bitch of the job, but did not have to drop the tranny. Now this guy deserves a beer (2)


Regards,
D

 

[Klink]

Ok, so I figured it out... Tomorrow - will see, but there SHOULD NOT be any more leaks, cleaned everything, sprayed and wiped everything bone dry, large tray with white cardboard under the car for the night.... Kinda bitch of the job, but did not have to drop the tranny. Now this guy deserves a beer (2)

If you didn't reset the piston, you likely just over extended that grooved shaft from the piston, which may result in too little B1 band clearance. That is an automatic clearance adjuster, and it can not be taken apart without being reset. If you compressed the shaft into the piston with force, then you likely damaged the diaphragm finger spring that retains the piston. That groove minus double the thickness of the clip IS the band free travel. You should replace the diaphragm spring as a precaution now since you have to remove it to reset the device anyway, and the early springs were a little too weak and failure prone anyway.

The diaphragm spring part number is: 140-993-14-26
The snap ring for the diaphragm spring is: 126-272-13-73
The "bastard clip" if you boogered it up and need one is: 126-277-29-73

 

[Duh_Vinci]

If you didn't reset the piston, you likely just over extended that grooved shaft from the piston, which may result in too little B1 band clearance. That is an automatic clearance adjuster, and it can not be taken apart without being reset. If you compressed the shaft into the piston with force, then you likely damaged the diaphragm finger spring that retains the piston. That groove minus double the thickness of the clip IS the band free travel. You should replace the diaphragm spring as a precaution now since you have to remove it to reset the device anyway, and the early springs were a little too weak and failure prone anyway. The diaphragm spring part number is 140 993 14 26. The snap ring for the diaphragm spring is 126 272 13 73. The "bastard clip" if you boogered it up and need one is 126 277 29 73.

Cheers and thank you very much for the diagrams, appreciate it!


I must admit, I got pretty lucky, didn't mess anything up, not even the bastard clip. When I tried to pull apart both plates, the clip became visible, was able to remove it... Then the shaft, and measured the original recess depth of the rod. Then, after cleaned everything up, dry test fitted it back together, and saw the faint oxidized marking on the shaft were original depth was set. Everything is back in place, drives and shifts perfect, very smooth!

But, yes, there is a BUT!!! B2 has a wetness around it... Would you happen to know if the white Teflon ring (red arrow) and the orange inner o-ring (17) are the same for B1 as they are for B2?

B2_piston

Any tricks or special instructions for reinstalling this one?

Huge thanks for the help!!!

Regards,
D

 

[gsxr]

If you didn't reset the piston, you likely just over extended that grooved shaft from the piston, which may result in too little B1 band clearance. That is an automatic clearance adjuster, and it can not be taken apart without being reset. If you compressed the shaft into the piston with force, then you likely damaged the diaphragm finger spring that retains the piston. That groove minus double the thickness of the clip IS the band free travel. You should replace the diaphragm spring as a precaution now since you have to remove it to reset the device anyway, and the early springs were a little too weak and failure prone anyway. The diaphragm spring part number is 140 993 14 26. The snap ring for the diaphragm spring is 126 272 13 73. The "bastard clip" if you boogered it up and need one is 126 277 29 73.

Klink, if what you describe happens, and there is too little B1 band clearance... what is the resulting problem / symptom you would notice when driving?

B2 has a wetness around it... Would you happen to know if the white Teflon ring (red arrow) and the orange inner o-ring (17) are the same for B1 as they are for B2?

No. The B1 and B2 seals are different sizes, different p/n's. While it's probably good to replace the Teflon rings, I've never done this. I don't think it's required unless they are damaged. The O-rings for the outer cover are the source of the external fluid leakage.

 

[Duh_Vinci]

...No. The B1 and B2 seals are different sizes, different p/n's. While it's probably good to replace the Teflon rings, I've never done this. I don't think it's required unless they are damaged. The O-rings for the outer cover are the source of the external fluid leakage.

I'm going to take that diagram above to the dealer tomorrow, they were a little confused to what part I was needed, but I think that would help with ordering that O-Ring (17) in that diagram. The teflon rings are only $10 or so, will indeed replace it as well, sh be considerably easier to do all than B1.

Regards,
D

 

[Klink]

Klink, if what you describe happens, and there is too little B1 band clearance... what is the resulting problem / symptom you would notice when driving?

Only a little tight, likely nothing. So tight that it drags? Burn it up. Too loose? Hard 1-2-1 shifts, and/or initial slip during a shift followed by too hard completion of the shift.

 

[samiam44]

Love the turn buckle to depress the B1 cover in the car! Great idea- yes there is a good place opposite on the W124 body.

The silicone rubber o-rings all absorb fluid w/time. MB would have been far better to use Viton than Silicone. Tranmission never gets hot enough ever to need silicone. Viton would hold up much better in these applications.


Michael

 

[Duh_Vinci]

Love the turn buckle to depress the B1 cover in the car! ...

The only thing I would have done differently (if I had to do this again) is to add the large socket, and sandwich it between the head of the bolt and an extra nut, this would have made a much sturdier tool!

But done, holding and that's that...

I did change B2 seal today, only o-ring orange one, there is no way to withdraw the piston out to change the white inner seal without dropping transmission out. at least on R129, there is about 1 1/8" clearance between the tunnel and the piston. Sooooo much easier to remove and reinstall than B1.

Went for a test drive, shift smooth, burns tires, no leaks, bone dry both B1 and B2! Progress!!!

Regards,
D

 

[Duh_Vinci]

If you didn't reset the piston, you likely just over extended that grooved shaft from the piston, which may result in too little B1 band clearance. That is an automatic clearance adjuster, and it can not be taken apart without being reset. If you compressed the shaft into the piston with force, then you likely damaged the diaphragm finger spring that retains the piston. That groove minus double the thickness of the clip IS the band free travel. You should replace the diaphragm spring as a precaution now since you have to remove it to reset the device anyway, and the early springs were a little too weak and failure prone anyway. The diaphragm spring part number is 140 993 14 26. The snap ring for the diaphragm spring is 126 272 13 73. The "bastard clip" if you boogered it up and need one is 126 277 29 73.

Deja vu... And Klink, that diagram you've provided is perfect, as well as description how to re-set the piston

WP_20181020_15_02_23_Pro by Duh_Vinci, on Flickr

Indeed, all new parts little bits of parts are new (again)

Regards,
D

 

[Phlyer]

Question on removing the B1 servo cover/piston assy.
I'm looking to replace the o-ring seal without removing the trans on my 1991 300E. Were the springs difficult to compress? Would you have been able to r/r the o-ring by placing the new o-ring around the turnbuckle and without removing the piston/cover assy. swap the o-rings? There isn't much room on the 124 chassis, so I'll probably lower the rear of the trans.

Thanks

 

[gsxr]

I've replaced the B1 cover O-ring with the trans in the car. It's not fun. The cover is difficult to compress. No room for a turnbuckle that I recall.

 

[Phlyer]

I've replaced the B1 cover O-ring with the trans in the car. It's not fun. The cover is difficult to compress. No room for a turnbuckle that I recall.

Understand that. Did you lower the rear of the trans to gain more room? I'm working on a tool similar to the factory press the will hopefully keep the springs and cover in place while swapping the o-ring

 

[gsxr]

Understand that. Did you lower the rear of the trans to gain more room? I'm working on a tool similar to the factory press the will keep the springs and cover in place while swapping the o-ring

From memory, I did lower the rear of the trans, but it only drops a few inches... doesn't make a big difference in access.

Biggest nuisance is keeping dirt/debris out of the B1 bore area, as the trans tunnel insulation is almost always disintegrating, and you end up constantly disturbing it while working.

If you can think of ANY excuse to just remove the entire transmission... it's usually worth the additional effort. Then you can easily re-seal the entire transmission front to back, top to bottom.

 

[Phlyer]

OK, thanks for the advice, and when the time comes I'll do a write up.