722.6 gearbox jumping into neutral whilst driving

[bricky0]

hi all i have a e320cdi estate on 2004 ive had 4 gearboxes fitted the last one last week the problem ive noticed again when i press the kick down button on the accelerator it jumps into neutral and also when driving slow in traffic 10-20 mph it feels like a shuddering, now the mechanic was telling me it could be my diff, then said it could me my wheels(which are off a 2001 s class) then last night he dipped the gearbox for oil and said it needs another litre in it and that will stop it, now im a fustrated because im spending money faster than im earning it so any help would be deeply appreciated
many thanks

 

[alexanderfoti]

So the first question to ask. Why has it had 4 gearboxes? All for the same fault?

 

[bricky0]

So the first question to ask. Why has it had 4 gearboxes? All for the same fault?

Mercedes specialist that I take it too first box original box broke into pieces there was pieces of metal in the oil
The second would not work diagnostics said 2nd 4th slipping so next box came and that was great for two years then problems jumping into neutral whilst driving was told by garage electro plate replaced that then still doing it then gearbox control module was diagnosed replaced that and still doing it jumping gears and banging when changing gears
So they said the box is knackered and was told these are a crap box so new one went in last week

 

[bob 6600]

I was under the impression that the 722.6 was a solid 'box

 

[Wighty]

Mother of God ! How much have you spent so far ?

 

[alexanderfoti]

I was under the impression that the 722.6 was a solid 'box

It is.

 

[bricky0]

I've spent way to much I love the car it's pulls my caravan with no problems but just can't seem to solve this issue I was going to get rid but decided to keep the car and spend money on some paint work but now with this on going issue I've already started looking for something else just want to get it right first

 

[V6Matty]

I'd be starting to think you've to glycol contamination, have you checked what radiator you have?
Personally I'd also be thinking of a second opinion from a different Indy, there's a couple around Manchester that are used by a few people on the forum.

You also mention you tow a caravan, did you have the additional gearbox cooling installed?

 

[bricky0]

The mechanic says no to glycol
And no to addition cooling

 

[umblecumbuz]

You haven't mentioned what mileage your car's covered, or what mileages each gearbox lasted for.
This info makes a difference to your tale of woe.

 

[bob 6600]

new one went in last week

Brand new or 'new' to the car (second hand)?

Who is supplying the boxes? Are they getting the correct part? The 722.6 is fitted to many models with small differences, they should ensure at least the 722.6xx is the same

 

[bricky0]

Car has done 209000
Box 126000

 

[bembo449]

im going to say this wether you like it or not pal , you should have bought a new or fully reconditioned box in the first place , its daft to pay to have another 2nd hand box fitted with that sort of miles on with no clue wether it is in a health condition and find yourself a better mechanic , all this guessing whats wrong is costing you way too much

 

[mioba]

hi all i have a e320cdi estate on 2004 ive had 4 gearboxes fitted the last one last week the problem ive noticed again when i press the kick down button on the accelerator it jumps into neutral and also when driving slow in traffic 10-20 mph it feels like a shuddering, now the mechanic was telling me it could be my diff, then said it could me my wheels(which are off a 2001 s class) then last night he dipped the gearbox for oil and said it needs another litre in it and that will stop it, now im a fustrated because im spending money faster than im earning it so any help would be deeply appreciated
many thanks

4th gearbox on 2004 merc and a 722.6 box. If it's the same mechanic changing them I would start to question if he knows what he is doing. I would also have become concerned after the 2nd box let alone 4th. At this stage I would certainly cut my losses and get another car and another mechanic.
Sorry to be harsh!

 

[umblecumbuz]

Car has done 209000
Box 126000

That kind of mileage for the car is not much.
My last two MB's, both with the 722.6 box which I have every faith in, were each sold at just under 200k miles. Original boxes, still working exactly as they should. Sump off and properly serviced every 50k miles obviously helped.
I am very surprised at your tale, and wonder if there's another factor not yet revealed here.