Slipping gears

[Fudger]

Guys, strange thing happened to me on the way back home last night. I was breaking just before a bend at 50mph down to about 35 I would say. All OK until I put the gas back on to drive round the bend. To my surprise, the engine revved up but the car was not in gear . Still rolling, I had to put the lever into neutral and back into drive for the gearbox to engage. All back to normal at that point and I carried on home without further strange goings on.

However, it does not sound too good to me that it would do this and a little disconcerting that it may happen again.

The car is a V plate 1999 C280 Sport estate (5 speed auto) with 38k on the clock.

I had the gearbox oil changed a few months ago as I thought the gearbox was a bit 'clunky' and I have to say I have not noticed an improvement since that was done.

Any of you out there any views as to what might be causing these problems?

Cheers guys.

Jonathan

 

[DITTRICH]

My auto box did something similar to me on one occasion. Not that I'm mechanical, but I thought it might have something to do with the electonic brain starting to initiate a gear change - and then changing its mind when I put my foot back on the accelerator. My situation resolved itself within about 5 seconds. I'd largely discounted and forgotten about it. However, your situation might not be exactly as mine.
Rgds
Les

 

[jan]

I had a similar experience earlier this year in my C200 CDI SE Elegance Saloon..
Approaching a roundabout I put my foot down as the road was clear and all that happened was the engine revved..no gear. I stopped the car selected N then D and all was right again.
I reported this to the dealer the same day as I thought it could have put me in a dangerous situation.
The 'auto box expert' came out with me for a test drive to see if it would do it again but of course it didn't.
He said he was not surprised as it was impossible for this to happen.
I insisted that it had happened and I had better things to do with my time than report fictitious faults..
He then put the car on the diagnostics machine and came back saying there was no recorded data to show anything unusual had happened with the gear box.
I had to leave it at that...what else could I do.
The problem has never re-occurred and I have done 12000+ miles since then.

Jan

 

[guydewdney]

you sure they changed the fluid? all of it? inc the stuff in the torque converter?

 

[GordonTarling]

Before I bought my Mercedes, I had a Volvo V70 which did exactly that same thing for a while. It frit the life out of me the first time it happened as revs went up to 5k or so before the next gear came in with a bang. Took a long time to get to the bottom of it (no fault codes etc.) but it turned out that it was caused by a sticking solenoid-controlled valve in the auto box. Don't wish to frighten you, but I had a new gearbox fitted under warranty.

 

[guydewdney]

Before I bought my Mercedes, I had a Volvo V70 which did exactly that same thing for a while. It frit the life out of me the first time it happened as revs went up to 5k or so before the next gear came in with a bang. Took a long time to get to the bottom of it (no fault codes etc.) but it turned out that it was caused by a sticking solenoid-controlled valve in the auto box. Don't wish to frighten you, but I had a new gearbox fitted under warranty.

hmm - exactltly the same thing has just happened to mine (722.622 'box) - caused by a bearing going, taking out the main input shaft and output shaft (1041 US dollars according to my epc )

Talk to George Fraser in Acton if it happens again (mine did it under heavy acceleration only)

 

[silverarrow]

i agree with gordon harling it is a known fault bearings wear out metal in fluid damages the control valve these days changing fluid with out a gear box flush not best advice .