W123 Transmission woes

[Noisy75]

Hi all,

W123 300CD 330k miles
started to get some issues with the transmission, took it to a shop here in LA, they changed the fluid, it ran just fine, was a bit harsh shifts between 1-2 and 2-4. They said to make sure it was warm before I drove it.

What prompted me to take it for a trans service was because it was always leaking trans fluid. Puddles remain, especially after a long drive.

Anyway, 5 months later, I was driving home, usual day, and it made a clunk noise. My hard shifting went away but it changes quickly through the gears.

Now, it take 6-8 seconds for D or R to engage.
when I drive it around the block if I floor it, I hear a wooshing noise, sounds like something is trying to spin up but I don't know.

I'm not driving it, I'm suspecting that the transmission clutch pack is shot.

What worried me is the state of the trans oil. It's basically black, not brown, not dark red but black. It's burnt. Why?

I was wondering if I did a trans service and stick some lucas stop slip in there. but if its a clutch pack, that would be hopeless, right?

The garage said that the transmission wasn't originally with the car and was probably replaced about 10 years ago. Nothing in the paperwork to suggest that though. Not sure how to check.


My questions are these:

1) The garage said that I had to test for the correct level by putting the car in R and then someone holding the brake on while the engine is warm. Is this right? it doesn't sound right to me..

2) why would trans oil heat up and turn black? would I need to replace the trans cooler/cooler lines as well?

3) Anyone know of a good and reputable transmission rebuilder in Los Angeles (preferably the San Fernando valley area)

I dearly love this car, and everything else is perfect, just this was really an unfortunate turn of events. If anyone can offer some advice where I should start, I would really appreciate it!

Cheers

[engatwork]

1) incorrect. Correct procedure is at operating temp put in park at idle and check level.

2) something up if it turns black in short period of time.

3) there is a reputable, high quality rebuilder on the west coast. I forget the name but I'm sure someone will come along in a little while and provide it.

[Frank Reiner]

N75:

Depending on the year model of the car, there are two different transmission models involved.
The well regarded trans shop is Sun Valley Transmissions.

[vwnate1]

The fact that they didn't understand how to check the fluid tells you that shop is clueless and should be ignored .

I'm sure they didn't bother (or even know) that you're able and supposed to drain the torque converter when doing tranny service, the fluid is shot and keep getting contaminated by the dirty fluid in the torque converter .

At this point even doing a proper service is a Hail Mary pass unless you're able to do it your own self or $pend another $200 on it maybe time to take it to Sun Valley Mercedes .

https://www.google.com/search?client=firefox-b-1-d&q=sun+valley+mercedes+transmissions+california

There's a bit more than just stuffing a $1,500 rebuilt tranny into it so be sure to have the right place do it .

Keep us posted please .

[merc lover]

I'll concur what VWnate said, you need a shop that really understands these cars to deal with the transmission. Call around and ask to speak to the shop owner to get a feel for their mercedes knowledge level. I have spoken with a LOT of shops that know and understand DOMESTIC cars (Chrysler, G.M. and Ford) but don't know or understand anything about german cars....

[vwnate1]

Are you still with us ? .

I hope so because this isn't rocket science, you at home with basic tools can sort this out .

If you continue to drive it without changing the ATF including the torque converter and the filter, it'll go along a while and strand you, then you're going to need $2,000.00 + to fix it and unless you get *just* the right shop you'll never get it right .

Reply please so we'll know if you need / want help .