Gear box dead on W124

[JimmyJam]

I was starting to look for another Merc as my wife has (much to my dismay) fallen out of love with our '92 W124 Estate. I then get a call this morning to say that it has lost forward gears (auto) on the school run. I managed to reverse all the way home! I'm assuming the worst so what is a repair likely to cost or fitting and replacement reconditioned one? I'm sure its beyond economical sense but need to think about all angles.
Cheers

[jith]

JimmyJam said:

I was starting to look for another Merc as my wife has (much to my dismay) fallen out of love with our '92 W124 Estate. I then get a call this morning to say that it has lost forward gears (auto) on the school run. I managed to reverse all the way home! I'm assuming the worst so what is a repair likely to cost or fitting and replacement reconditioned one? I'm sure its beyond economical sense but need to think about all angles.
Cheers

Before you write it off, try dropping the transmission sump and renewing the micronic filter and fill with fresh fluid. I have cured countless Merc transmission problems simply by doing that.

J

[JimmyJam]

Worth a try, cheers

[BlueMR2]

Search for, i think its the B2 valve or solenoid, these fail and you lose all forward gears but reverse is fine i believe.

[BlueMR2]

http://www.w-124.info/w124/b2piston.pdf

http://www.mbca.org/forum/w124-transmission-advice

[r129sl]

4 speed trannies are dead cheap and swapping them over is not the end of the world. 5 speeders are more expensive.

[bolide]

r129sl said:

4 speed trannies are dead cheap and swapping them over is not the end of the world. 5 speeders are more expensive.

I'd go along with that. It takes a few hours to swop the boxes, and you'll spend the thick end of £100 on an oil & filter change, but it's what I'd do. Apart fom anything else the car is valueless without a gearbox

The 5-speed boxes are hard to find

Nick Froome

[r129sl]

I've got access to a good 5speed auto if any wants it. It's in my old 320 which my local garagiste bought from me and is now breaking.

[W124Bob]

Just out of interest can you retro fit a 4speed into a car thats had a 5speed?

[r129sl]

I don't think so. Two reasons. First, I suspect the rear end is a different ratio. Second, the five speed is partly ECU controlled and hooks up with various systems in order to determine shifts (at least to and from fifth) and I suspect they just wouldn't be there on a four speed car. Otherwise I'd put it in my diesel.