'83 300TDT NeedleBearings in Filter

I recently put a used transmission into a friends car, and adjusted it according to the mercedessource manual with the mercedessource tools, etc.

The used unit I pulled was from a crunched car ( a good sign the car was being driven before arriving in the junkyard) the fluid was clean, didn't smell, as well as no metal in the pan. The number matched (722.315). It seemed like a good donor.

It was without a torque convertor, so we used her existing one — draining it prior to installation, etc.

When we first put the transmission in, it shifted WAY better than the old one ever did — which the friend had for about 10 years. Seemed like great news, and a successful transplant.

Then when I was on vacation, the transmission apparently started slipping. Since I wasn't there to check the adjustments, etc. she took it into a mechanic who specializes in MB. He even has a W123 diesel wagon.

I was concerned about another person adjusting it, but she said after he adjusted it, the slipping stopped.

Then a few weeks later she called and said it felt like the B2 piston was breaking or broken. She had driven in her car when the B2 piston broke on the previously replaced transmission, so she knew what it felt like.

I got the new parts to do the B2 piston replacement/upgrade. When I took the piston out I found it was not broken.

After getting up from underneath the car, I noticed the throttle piece at the firewall was totally shot. I figured that was the fault to her weird acceleration problems. I ordered a replacement from you guys... but I decided to check inside the filter just as a precaution to keep tabs on the transmission since the B2 was obviously not the problem.

As I checked the filter, I found a bunch of small needle bearings inside the filter.

Is there any way that you can tell exactly where the needle bearings came from by their measurement? The reason I ask is that if there is any chance that the bearings came from the torque convertor, that would be fantastic news all things considered, right?

I mean, better to need to replace the torque convertor than the entire transmission (again).

Also, could the previous mechanics adjustment have ruined this needle bearing/torque convertor/transmission? It was improperly adjusted way too high.

Thanks,
Brett
1982 300TDT (250,000 mi.)

Forums

Transmission / Suspension Specific Aid

Chassis Model Number

W123

Not a good sign

If you have needle bearing in the pan that is not a good omen. That means they have worked there way through the transmission pump, etc. Probably causing other damage along the way. You would probably have to take it apart to determine where they are coming from and that is a lot of work! I do not believe that any external adjustments would cause the problem you describe.

Just bad luck, then?

OK, we were obviously hoping for better news. Good to know the mechanics adjustment of the governor to above 48psi did not cause this.

I guess it was just plain bad luck then, huh?

I did everything to ensure a good donor, but I guess when you're putting in a used transmission there's always a risk that it'll fail prematurely.

For what it's worth, the installation & adjustment instructions from you were fantastic. Couldn't have done it without them. It sure drove really nicely for that short time it was in the car, based on my initial test drives as well as her reports & feedback.

I'm afraid that for her that means likely getting rid of the car since she just went through putting in a used replacement. Hindsight I guess she should have spent more and put a rebuilt in.

Sad that another wagon will be off the road and in the junkyard.

–Brett