Gearbox woe

[herman1rg]

I have a 1996 (P) E300D which has developed a gearbox problem.

It's the auto 4 speed box and when in drive (D) it changes up 1-2 OK, 2-3 OK but then seems to fail to find 4th and loses drive and the engine races to high revs.

Any advice as to problem?

I'm in Peterborough so advice as to local auto box specialist for any needed repair would also be helpful.

 

[SilverSaloon]

I have a 1996 (P) E300D which has developed a gearbox problem.

It's the auto 4 speed box and when in drive (D) it changes up 1-2 OK, 2-3 OK but then seems to fail to find 4th and loses drive and the engine races to high revs.

Any advice as to problem?

I'm in Peterborough so advice as to local auto box specialist for any needed repair would also be helpful.

Does it actually loose drive and return to neutral or is this just a flare between changes? ie it revs as it changes but does actually then change into Forth?

If its a flare then you need to remove the vaccum to the gearbox modulator and see if it still flares... if it doesnt then you have a vaccum leak.

i fixed a flare on my car that happened between 2nd and 3rd by adjusting the modulator. Turn clockwise to remove the flare, but this will probably make gearchanges more harsher. Its a trial and error affair (if you dont have the right tools) to get it to a correct level where it feels right.

The modulator is located next to the gearbox under the car, passenger side (in the UK)

When was the gearbox oil last changed? might be worth looking into aswell...

 

[BlackC55]

Check the level first. Your car should have it's own dipstick. Check with engine running.

 

[herman1rg]

Loses drive doesnt find 4th at all

 

[herman1rg]

Check the level first. Your car should have it's own dipstick. Check with engine running.

Easy to do?

 

[SilverSaloon]

yep, get the car to standard temp - 80 deg

as the engine is running.... in PARK

then on a level surface, pull the gearbox dipstick that is situated at the very back of the engine bay (look for red cap). Check in same way as engine oil.

should be at the correct level for 80 deg.

Smell the oil aswell - it shouldnt smell burnt and should be a cherry-ade colour.

This how-to HERE is the same for your car (whether its a W210 or a W124), however note that the 'pan bolts will warp the pan if tightened too much. the 124 doesnt have the special bolts as mentioned in the thread. I discovered this in the worst way possible. New pan is about £50 from memory.

 

[herman1rg]

Level checked -ok

Fluid cherry red

next?

 

[SilverSaloon]

Level checked -ok

Fluid cherry red

next?

Someone else may have further suggestion, but I think its going to require more mechanical work

 

[Buggerlugs]

K2 clutch feed seals blown out = nil 4th gear, very common on these gearboxes, gearbox removal and full strip required to confirm.

Also possible broken K2 accumulator bias spring, or jammed 3-4 shift valve, valve body strip or swap required to confirm, this can be done with the gearbox in the car.

Either way, you're looking at an internal gearbox fault, so bearing in mind the age of the car a good used gearbox install is what I would recommend.