2008 W211 E280 Two jerks, slight clunks when shifting from park to reverse?

[Paragon1970]

Hi Folks,

Just received the car back from mechanics after it had a transmission oil and filter change.

Now I am not entirely sure whether the following used to occur of whether I noticed it since I was conscious of the work that had been carried out.

When I shift from park to reverse I feel the reverse gear kind of engage twice.
ie I feel the car slightly move back with the first slight clunk and then there is another about a second later, foot break is engaged (it needs to be to engage reverse from park)

Does anyone else experience the same, is this normal behaviour?

Thanks,
SRG

 

[streethawk]

No not normal. Did they check the transmission fluid was at the correct level when hot?

 

[Paragon1970]

I have no idea how they checked it, I took it to my local indi that only deals with Mercedes vehicles so I would expect that they should know what they are doing, but will check with them all the same.

Thanks
SRG

 

[Paragon1970]

So just called the garage, they are basically saying can't see how it could be related to anything they did since they simply drained the oil changed the filter and seal and refilled with a special measuring pump. Went on to say that they do five or six of these oil changes a week and have never had any issues.

Anyway they did agree to take take a look and put it on their diag machine tomorrow, not sure if their diag machine will pick up any additional details then my cheap OBD ebay torque diag tool that is showing no fault codes found.

Really could do without this hassle as planing to take the car to the french alps in the near future.

Cheers,
SRG

 

[streethawk]

I'd be taking It back to them if I had a problem. On mine there is also a drain plug on the torque converter so I'd of expected them to change the whole lot and not just what's in the box. If I remember correctly mine took 8 litres of atf and I also had mb fluid. To check level on these boxes the fluid needs to be upto temperature 80 degrees iirc then you can undo sump plug on the transmission and if there is too much some will drain out. It has a tube inside the sump where the plug is which at its top is the correct level. To much oil can be just as bad as too little.

 

[streethawk]

If they have a star it will tell them all they need to know.

 

[markmifsud]

as above, get it on star. I have heard of the selector mechanism being the cause of something similar, more so it it goes into limp and sticks to one gear

 

[Paragon1970]

Thanks for your replies folks.

Mechanic ran star diagnostics, no errors reported.
I was told that they default reset the auto box program or something along those lines.
Picked up the car and it seems much better now.

Did not notice the double engagement sound from park to reverse, the gears generally feel much smoother too.

Quite surprised the difference it made if I am honest.

Thanks
SRG

 

[streethawk]

Happy days