2004 S55 transmission lurching\bucking 2-3rd
My new to me 2005 S55, 5 spd trans, 120K is bucking hard on cold shifts between 1-2 on sport and 2-3 on comfort settings. Just completed a full tranny service, looked like an aftermarket fluid had been used. No metal chunks in the pan but more than average clutch material on magnet and bottom of pan. Did a second drive and fluid change draining the pan and found some discoloration of fluid. Torque converter does not have a drain plug. Did one more drive, drain, refill. Fluid looks clean now. Reset adaptation. When warm, fairly smooth up shifting but a little bit of shudder on downshift at low speeds. Also changed the transmission mount.
Did a glycol test and was negative. No leak at the at the wiring adapter plug.
I've used all geniune MB fluids. Removed fluid was thin and brown (did not smell burnt). Changed fluid multiple times using combination of methods (yes, a couple hundred bucks in trans fluid) and problem seemed to improve but returned quickly. Also reset adaptation in the trans..
No stored nor new errors when hooked up to star diagnostics.
When pulling away from stop, if I don't feather the pedal just right, on shift the S will start bucking so hard it'll snap your neck. Doesn't seem to happen after driving a while, but I'm also compensating a bit.
No codes either before flush or after.
I'm at a loss where to go next. Searched the forums and didn't find similar problem other than radiator contamination but my former MB tech, now independent, tells me my radiator was not one of the problematic series.
Looking for where to go next short of replacing the transmission.
Thanks!
Trending Topics
The Best of Mercedes & AMG
The symptoms of my 722.6 though seem different than what I've read and there are no codes. The bucking upon acceleration when cold will snap your neck in low gears This is not a "hard" shift; this is a holy moly watch out for whiplash kinda shift on fairly low acceleration. Paddle shifters don't alleviate it, either. I'm trying to find a way to diagnose rather than change out the plate, try again, rebuild the torque convertor, try again, etc. Hope you can apprecaite my effort. Thank you for the advice and the reference to the articles.
Last edited by buddysharp; Jul 20, 2015 at 08:19 PM. Reason: erased part of my original by accident


