QP3

Hi,

I was wondering were the most reputable sources are for transmission work on this car, which I believe has the 722.636 transmission. I get the judders every so often, usually at certain speeds/throttle, and backing off or stepping on the gas stops it. It doesn't seem to be the typical slipping or not going into gear, but does seem to be transmission related. Could it possibly be the torque converter not locking up?

Was thinking that since I don't know for certain that the transmission has been replaced or repaired before, and my car is up to 150000 miles, it's probably around time for a rebuild/replacement.

Are there any good shops or places for transmission work you could suggest (DM is fine if the mods don't want referrals posted here), ideally in SoCal?

Thanks!

Fried Chicken

Are you sure it's the transmission?
Don't guess or throw parts/service at a problem with these cars.

From what you're describing, I would suspect the rear subframe mounts. Mine does the same thing. It's annoying. The bolts are stretch bolts, so one-time-use, although that might have changed since I last checked.

Regarding the transmission, with 150k miles, a good transmission service can't hurt.

QP3

I'm not, no. Unfortunately I don't have a lift or place to look at it. Are there any ways I could try to isolate the problem?

Fried Chicken

These cars are designed and built to be worked on with experienced people and full service centers. I don't say this arrogantly or snobbishly, it's literally what it is.
Pay a dealership the $300 for the diagnostic or whatever it is they charge, and let them know you want to do the work yourself. They will work with you. In fact, they're so overburdened with work right now, they will probably be happy to simply do a diagnostic and provide some guidance. Mercedes is amazing and different that way.

QP3

Dropped the car off this morning, will know more in a day or two what the problem(s) is(are).

My bet is most certainly transmission. Beyond that, hard to say.

Thanks for the feedback.

Fried Chicken

Keep us updated.

QP3

Had the car diagnosed, was the transmission. Found an OEM shop that only does Mercedes and went directly to them, car ran like a dream for a few weeks, until it refused to shift. Tried resetting it, which worked on the side streets until I got on the freeway, when it again refused to shift.

Took it to my local shop, the transmission was fine, turns out the shifter had finally failed and had to be replaced. As part of the anti-theft system it has to be coded to the car computer and ignition. Once I got that replaced, everything has been working fine.

Went to replace the supercharger pulley bearing today (on advice from my local shop, a straightforward DIY job), and found that the registration pins that fit onto the washer behind the locking bolt had sheared off. I've started a separate thread about that if anyone is able to weigh in.