Johncl63

Car is 09 CL63 AMG 87,000 miles full MB history but no evidence of a gearbox oil change

Ok so back to an old issue that despite visiting several amercedes specialist AND Auto Box Specialist no one wants to commit to a fix.

So here goes.

Symtoms.

NO fault codes in gearbox.

Any speed or rev range a SLIGHT touch of the throttle results in a violent judder/shudder that feel like its coming from the middle (just forward of the centre are rest) OR rear left. Described as driving over a cattle geid or rumble strip. Does it in sport, comfort, but less so in manual. Lots worse on an incline and lots worse at lower revs.

The other morning we had a slight frost, i started the car and let the womdows defrost, the car was in comfort, put into drive and before i could get my foot of the break the car lurced forward and stalled. This happend twice. It also did it on reverse. Tried to go from neutral to drive and it stalled. Put it in sport a few mins later and it still lurced but managed to get my foot of the brake and get going. This morning not as cold and i got away first time. One its been run it doesnt do it again on start up.

On wide open throttle there is NO issue it pulls hard.

The car has NO missfire, as thats what a few people thought and to be fair it did have a missfire. I baught this car to keep, icknow they are money pits but hey, you cant take it with you! So to fix the missfire i replaced both intake gaskets, all inectors, all spark plugs and oil breather and all Coils (coils i could if got under warrenty but im inpatient!)

An abs sensor was down so that has also been replaced.

Drove train we have changed the centre prop bearing and had it balanced. Both of the other 2 prop fixing look relatively new.

Gearbox oil level is ok.

Now given what happend to me in the morning its deffinatly making me go gearbox. But no one wants to commit to what it is in the box. I still say torque converter.

Here is a vid. While its not very loud on the vid beleve me when i say in the car just imadgen youve gone over a rumble strip at 70 and feels like a cattle grid at 80! Also not when it does it the revs rise ever so slightly before going back down.
https://youtu.be/cD_woCKOwy4

George993

Check if all ABC suspension sensors and arms which pull/push on the sensors are bolted tight. I had one of those loose and the car would unexpectedly jerk on slight body movements (acceleration/slowing/changing lane) but without a clear pattern, so it took me a while to find the problem. As the car position sensed by ABC computer rapidly changed, ABC responded violently.

If the problem is clearly from the drive train the reason could be different, but checking bolts is simple enough to do anyway. Good luck.

George993

Also regarding misfires - a Mercedes can have undetected misfires which don't show up on any error readouts and don't trigger CEL. The way to check is to monitor "real time" counts in DAS with engine running/driving. Misfires may be occurring and clearing/timing out without any notifications if they occur at certain slow patterns. But they can still be causing very slight jerks of the car.

MaxBB

My car: C63S Cabriolet 2018 7-speed gearbox

• Candles replaced (not solved the problem) The candles were in poor condition 2 were burned out.
• Reel change n ° 5/6 (it seems that the problem is solved .. I look forward to test better)

japamg

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