Mercedes CLK55 AMG Gearbox Issues - Advice Needed
Discussion
I have a 2004 Mercedes CLK55 AMG Convertible with gearbox issues (722.6 box).
The current symptoms happen while the car is cold and are as follows:
- Changing in automatic mode from 1st to 2nd is very jerky/shunty. The only way I can describe it is like an elastic band stretching and then letting go as the car goes into gear
- The revs between 20-30mph hover as though something is slipping in the transmission
- Quick downshifts in manual mode (both when car is cold or warm) make a loud noise like something is dragging/locking up
Once the car is up to temperature the first and second issues disappear entirely and the car drives like normal in auto mode.
The car has had a gearbox service and the conductor plate replaced by a Mercedes/AMG independent specialist (the conductor plate solved a previous problem where the car was getting stuck in second gear occasionally).
The car is currently sitting with a highly recommended local gearbox specialist who has had the car for almost a month now and not come up with any solution. They first tried telling me it was linked to a fault code relating to the secondary air pump (another common fault on mercs of this age) which it clearly isn't. This morning they have called again to say it is not a gearbox fault because the fault isn't replicated when the car is in manual mode and that it must be a fault with the engine despite there being no fault codes or any obvious engine faults. I get the impression they just don't want to do the work on the car and the only checks they have done so far are plugging the car in and taking it for test drive a couple of times.
I'm at a bit of a loss as I want the car fixed and am willing to spend the money to get it right. The above feedback from the gearbox specialist doesn't feel right to me and all I have achieved so far is wasting a month of time without the car.
I am only the second owner of the car and it has stacks and stacks of service history and maintenance. I don't want to sell it on cheap with the gearbox fault.
Can anyone shed any light on possible issues and if it could possibly be an engine fault?
The current symptoms happen while the car is cold and are as follows:
- Changing in automatic mode from 1st to 2nd is very jerky/shunty. The only way I can describe it is like an elastic band stretching and then letting go as the car goes into gear
- The revs between 20-30mph hover as though something is slipping in the transmission
- Quick downshifts in manual mode (both when car is cold or warm) make a loud noise like something is dragging/locking up
Once the car is up to temperature the first and second issues disappear entirely and the car drives like normal in auto mode.
The car has had a gearbox service and the conductor plate replaced by a Mercedes/AMG independent specialist (the conductor plate solved a previous problem where the car was getting stuck in second gear occasionally).
The car is currently sitting with a highly recommended local gearbox specialist who has had the car for almost a month now and not come up with any solution. They first tried telling me it was linked to a fault code relating to the secondary air pump (another common fault on mercs of this age) which it clearly isn't. This morning they have called again to say it is not a gearbox fault because the fault isn't replicated when the car is in manual mode and that it must be a fault with the engine despite there being no fault codes or any obvious engine faults. I get the impression they just don't want to do the work on the car and the only checks they have done so far are plugging the car in and taking it for test drive a couple of times.
I'm at a bit of a loss as I want the car fixed and am willing to spend the money to get it right. The above feedback from the gearbox specialist doesn't feel right to me and all I have achieved so far is wasting a month of time without the car.
I am only the second owner of the car and it has stacks and stacks of service history and maintenance. I don't want to sell it on cheap with the gearbox fault.
Can anyone shed any light on possible issues and if it could possibly be an engine fault?
The hovering revs sound to me like a torque converter lockup issue, I had similar on my S600 with the same box.
Good the conductor plate was replaced, it's always the first thing to try before spending real money. It doesn't help that these MBs will be losing power, slipping, smashing into gear, all sorts of nonsense and not record a single error code.
I'd take it somewhere else though, it's clearly a gearbox issue and they clearly have no idea how to diagnose it.
Good the conductor plate was replaced, it's always the first thing to try before spending real money. It doesn't help that these MBs will be losing power, slipping, smashing into gear, all sorts of nonsense and not record a single error code.
I'd take it somewhere else though, it's clearly a gearbox issue and they clearly have no idea how to diagnose it.
GeniusOfLove said:
The hovering revs sound to me like a torque converter lockup issue, I had similar on my S600 with the same box.
Good the conductor plate was replaced, it's always the first thing to try before spending real money. It doesn't help that these MBs will be losing power, slipping, smashing into gear, all sorts of nonsense and not record a single error code.
I'd take it somewhere else though, it's clearly a gearbox issue and they clearly have no idea how to diagnose it.
Agree, I just don't see how it couldn't be a gearbox issue. Trouble is this place was recommended by multiple people and is one of only a few locally so I'm a bit stuck for alternative places to look at it. Any recommendations? I'm in Norfolk but happy to travel for the right specialist.Good the conductor plate was replaced, it's always the first thing to try before spending real money. It doesn't help that these MBs will be losing power, slipping, smashing into gear, all sorts of nonsense and not record a single error code.
I'd take it somewhere else though, it's clearly a gearbox issue and they clearly have no idea how to diagnose it.
jhubs139 said:
Agree, I just don't see how it couldn't be a gearbox issue. Trouble is this place was recommended by multiple people and is one of only a few locally so I'm a bit stuck for alternative places to look at it. Any recommendations? I'm in Norfolk but happy to travel for the right specialist.
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