HELP ! Auto gearbox slipping into neutral....

[marshy76]

I hope someone on here might be able to put me out of my misery, and scrape my bottom lip off the floor ??

I have recently bought a C220 diesel Avantgarde SE, 5 yrs old with 67k on the clock.

A couple of months into my relationship with said merc, she got stuck in second gear a couple of times. Pulling over and switching off, resting for ten seconds & restarting seemed to clear the problem, until one day it just wouldnt come out of second at all. A trip to the nearest MB dealer ended up with a new electric pack in the gearbox, and £550 later, I was mobile.

HOWEVER - a couple of days later, under "normal" driving conditions, it started to slip into neutral, usually when pulling through a roundabout, or onto a motorway slip road, which can obviously be fairly hairy !

She went back to MB, who checked if the part was faulty by swapping for another electric pack, proved it wasnt , and then charged me £350 for the privelege !!

So, off I went to an auto gearbox specialist, who was puzzled by this problem, as there was no trace of any faults on the diagnostic machine.

His best stab was to replace the neutral switch, which to me looked like the entire gear selector mechanism.

Two weeks later, and its done it again !!! This time I am also noticing an apparant slip when it is changing ( i think from 2nd to 3rd), where the rev counter slips up about 1000rpm before changing gear.

PLease can someone try to convince me that my gearbox is not about to fall out ?

I have saved my hard earned for a long tme to be able to buy this car, and I thought i was buying a decent car with solid reputation for reliability.

Any advice will be greatly appreciated, whether its good news or bad news, -please dont hold back.

Thanks ( in anticipation)

 

[vijilants]

May be the torque converter ?

By the way, I dont think MB should have charged you...after all, the fault was not fixed and all they did was replace a part that the had already fitted that they thought could be suspect.

If I were you , I wouldn't have paid or would certainly challenge this.

Whereabouts in the country are you ?...A decent auto gearbox guy who is familiar with merc boxes should be able to diagnose.

 

[marshy76]

Im in the little sleepy hollow of Preston, Lancs. ( Englands newest city !)

Youre right, and I am challenging the issue with the MB dealer, although i sheepishly paid them to get my keys back, with the promise of a detailed discussion later on. Bit daft really.

The auto gearbox specialist is baffled, because every time i take it back to him, he cant get the car to replicate the fault.

Im hoping it may be something simple, like a screw that needs tightening, or some fluid that needs changing ?

Or could it be a clutch issue ? If so is this big problems, or a wee swap over job??

(As you can probably tell im neother mechanically or technically gifted !!)

Im just worried that im either faced woth another bill for a few thousand squids, or my car is going to melt one day ?

Someone, please cheer me up !

 

[vijilants]

If the 67K is genuine, you shouldnt be slipping gears due to the fluid, unless the level is low.

If MB changed the electronic controller plate in the gearbox they woul have refilled the box with new fluid.

The torque converter is the "clutch" on an auto box.

Unfortunately I dont know of any Auto box specialists in your area of the country as I am in London......try posting for a merc gearbox specialist in your area.

Dunno if this will help....they are supposed to be very good:

http://www.fedauto.co.uk/memfind.htm

 

[jpbp200]

Have you had the ATF changed? The symptoms you describe perhaps suggest a potential fluid problem in the first instance. Maybe even worth getting an oil sample spectro analysed (about £20) to point you in the right direction.... BTW MB def should not have charged you extra. The fact that that dealer has failed to give you the service you require should suggest that you choose another one in future, after getting a FULL refund from the original dealer as the problem has not been resolved and they have replaced unessesary parts twice! MB auto gearboxes are very well built. the fact that the fault cannot be replicated by the specialist is puzzling and would definately inspire me to have an ATF change although any self respecting MB dealer would have recommended this anyway. More background required I think......

 

[jpbp200]

If MB changed the electronic controller plate in the gearbox they woul have refilled the box with new fluid.

Ask them specifically if this was done. If so get another dealer to verify new ATF.