transmission on a 124.128 - PeachParts Mercedes-Benz Forum

vaccin · #1 08-01-2013, 10:08 PM

This is a seal replacement at the rear servo cylindrical disk which is on the right rear side of the transmission. The cylindrical disk is easily pushed in and does not press hard against the outer lock ring. I have a steady flow of oil out through the servo.
edit:I forget the last sentence sorry. The cylindrical cover can easily be pushed in without an noticeable pressure on the rear servo, Is this normal and is this procedure possible with the trans bolted in.
This is a 722.4 thanks

JamesDean · #2 08-02-2013, 10:26 AM

The 124.128 uses the 722.409 transmission

RIGHT SIDE

LEFT SIDE

You are just trying to replace the seal on that servo?

I believe that rear most servo is the B2 piston. The front most is B1 piston. The oddly shaped guy further rear and slightly up from the B2 is the transmission's secondary pump. I believe these were removed in the 1992 model year. I have heard that they can seize and cause the governor to snap its plastic drive gears. Taking the governor out of the picture will result in only having 1st gear.

The plate should press in easily, allowing you to remove the snap ring that holds it back. From there carefully remove the seal on the bore and replace it. Then install the cover and snap ring and you're good to go.

vaccin · #3 08-02-2013, 07:27 PM

The build date on my 92 is july and this is the transmission I have you were so kind enough to post.
On the right side Ahead of the secondary oil pump Is the B2 servo , ahead of that is the B1.
I have a transmission from a 1990 300d which has no forward or reverse and the B2 servo cylindrical cover took everything I had to push in, and did not return against the outer lock, I was trying to find a comparison.

Back to my transmission , The cylindrical disk on my B2 pushed in so easily and just barely returned to the outer lock without any real psi but the return psi maybe is not what seals the cover because the seal is behind the cover if I am reading this picture right part 364.

http://www.ganzeboom.net/images1/ganzeboom/parts/Mercedes/722.3,%20722.4.pdf

JamesDean thanks for this.

vaccin · #4 08-05-2013, 04:39 PM

The cylindrical cover pushed in easy enough and the bright orange o-ring removed easy enough also.The bore and surrounding area were cleaned with cotton and paper towels with the transmission bolted. I am trying to source an o-ring which I am considering a complete gasket kit for back-up.

JamesDean · #5 08-05-2013, 06:13 PM

I highly recommend buying the o-ring from Mercedes. I can get you part numbers if you need and they are usually pretty affordable.

vaccin · #6 08-05-2013, 08:33 PM

If you have a part number from MB I will use for sure. MB ordered an engine coolant drain from AG which I picking up soon.

JamesDean · #7 08-05-2013, 10:41 PM

Here is a screenshot from the EPC:

I selected the B1 and B2 pistons and their bore seals and snap rings.

vaccin · #8 08-07-2013, 07:41 PM

I cannot access the epc for the 1 year trial because i'm in the north.
I ordered the o-ring this should stop the flow.
Thanks Dean.

JamesDean · #9 08-07-2013, 10:56 PM

Yeah I forgot about that the free EPC is USA only for some reason.

Let me know if you need any other part numbers.

vaccin · #10 08-08-2013, 08:40 PM

Pm sent.
Parts numbers are available but I cant seem to find. Anyone>

Stretch · #11 08-14-2013, 02:12 PM

Can't the site sponsors help?

vaccin · #12 08-16-2013, 12:22 AM

I'm Good now for this part. The local mb dealer is a 2 hour drive. Thanks.

vaccin · #13 08-18-2013, 09:26 PM

I'm following up on the b2 servo seal that was passing the trans fluid like a globe valve.
The o-ring is a time consuming fit because of the limited space to work and the fit is real tight upon buttoning up.
When I initially had the servo leak this was so foreign to me my initial thoughts were this could be a good time for a complete oring and gasket kit because of my mileage.
My inboard and outboard seals could stand for replacement but this servo fix will get me through till next year when I will hopefully have more time.
I changed the filter and fluids from the torque/rad/transpan before the servo repair and I overfilled the transmission when topping up and then drained a liter out and refilled.