CLK W208 Strange transmission issue

[JackofHarts]

Hi, first post here but i've tried searching around and can't find my issue. This morning i came to a set of lights, left it in drive foot on the brake waiting for the change, when the lights changed and i let the brake go and went to accelerate but went nowhere. Hazards on panic ensues, and i try switching back to park and then to drive and nothing, revs sluggishly. So i put it in neutral to try and coast to the side of the road, but it acts like it's in drive, i'm able to drive it normally, no limp mode, no check engine lights or error lights but the gear selector is in neutral.

I cannot select reverse, it will only move forward in neutral, even shifting gears whilst in neutral, kick down is operational too. My first thought is transmission fluid change and see if it's like a glitter party in there, conductive plate or maybe gear selector. I just can't seem to match any symptoms with anything else i've found, so struggling to diagnose.

[Hoofy]

Probably not a helpful post but am interested as I prefer autos and Mercedes gearboxes are supposed to be good.

Strange. Was it displaying any other problems prior to this? Gearbox flare? Jolting when going round a mini roundabout and the gears not being selected quickly enough?

[JackofHarts]

Hoofy said:

Probably not a helpful post but am interested as I prefer autos and Mercedes gearboxes are supposed to be good.

Strange. Was it displaying any other problems prior to this? Gearbox flare? Jolting when going round a mini roundabout and the gears not being selected quickly enough?

The only strange behavior it was showing before was that when punching it and getting high up in the rev range, it would change with a jolt, but normal driving was fine.

[Hoofy]

JackofHarts said:

Hoofy said:

Probably not a helpful post but am interested as I prefer autos and Mercedes gearboxes are supposed to be good.

Strange. Was it displaying any other problems prior to this? Gearbox flare? Jolting when going round a mini roundabout and the gears not being selected quickly enough?

The only strange behavior it was showing before was that when punching it and getting high up in the rev range, it would change with a jolt, but normal driving was fine.

That does sound like a problem was raising its head. You might be lucky and an oil change is all that is necessary as this fixes helps mild gearbox flare but it might be too late.

Good luck and keep us updated!

Oh, you might want to try the Mercedes Benz owners club forum. https://forums.mercedesclub.org.uk/index.php

[shentodj]

could the gear stick/ selector have come loose so its showing wrong position?

[alabbasi]

Try switching the engine off and back on again. The 722.6 transmission is pretty stout but can suffer a couple of issues:

1) Electronic plug - This plug can leak and cause fluid to creep up the wires and into the TCU which could cause the car to go in limp home mode
2) Brake switch - Tied into traction control can cause limp home condition, will trip ABS and ASR lights
3) Conductor plate - This is the electronic part of the valve body which can fail every 100k miles or so and cause really odd shifter
4) Electronic shifter, can act out if you've spilled a drink
5) Often considered as a sealed for life transmission, you need to change the fluid and use a compatible 236.10 fluid

All of the above except #4 are cheap and should be considered as part of the service items when fluid is changed

A good quality scanner that can read through the 38pin connector will tell you if a code has been tripped.

Also put the car up in the air and check the shifter link bushings. If it's acting like it's in drive when it's in neutral, the bushings may well be perished.

Good luck

Edited by alabbasi on Tuesday 25th February 04:31