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2,762 Posts
Discussion Starter · #1 ·

surprise surprise, the gearbox oil change didn't fix the persistant problem of grinding into the 3rd - only on the up-change tho, and only when revving hard in 2nd.

The garage said the oil it had in there was waaay too thick - no doubt put in to disguise gearbox problems i assume. No sawdust
at least tho!!!

So what I'd like to ask is - am i jumping to conclusions - could it be synchromesh or something else (bear in mind, just had new (re-manufactured) clutch, and new slave cylinder)?

And if it is gearbox, how much other work is required to step it up to a 6 speed other than 'dropping' the box in? And how hard are the 6 speed boxes to get hold of, and what's the difference in price?

Reckon I'll be delaying interest in the short shift kit untill I sort this!!!



Moderator Emeritus
4,273 Posts

Sorry to hear about your problem.

Do you have any other percieved faults with noise when shifting up & down through the other gears ?

Have you tried a timed shift from 2nd to 3rd without using the clutch ie
accelerate-lift throttle-shift 2rnd to neutral to 3rd.

What does it do after this ?

Is the noise a whine graunch or thud.

Now try the above from 3rd to 2nd.

Does it make any difference.

The getrag 280-290 series does not suffer servicing abuse well & it would appear that a lot of these boxes suffer on the 2nd & 3rd gear clusters & syncronisers. (I wonder why...!)
I have changed the trans & diff oil every 12k or once a yr if you like.
I think these boxes can last as mine has done way past 160k miles with absolutely no problems & a few track weekends under its belt.

I dont think these boxes failing is all down to owner abuse.
The same box was used in the supercharged 6 cyl DB7.
This car had similar overall power & torque but is heavier.
Tests showed that accelerated wear took place when the fill for life approach was taken as opposed to a change of oil every 24k.
This is a fact.

I cant prove it but I think a lot of dealers did not & continue not to address the driveline oil changes.

There is a mag trap on the rear of the drain plug but it can only collect so much debris & this combined with incorrect grade of trans oil does not bode well.

The thing is with splitting one of these boxes is that you only want to do it once. What else may have been damaged or worn apart from the syncronisers if indeed that is your problem.
The box is full of anti rattle shims which have a habit of disintegrating & f**king up the synros & getting chewed up by the gears so lots of nasty bits of metal beacome a grinding paste that eat through the heat treated surface of the gears.

Rebuild or replace ?

Good luck & welcome to the world of E34 M5 motoring....

Take care

1,166 Posts
Farrel said it...

About the 6-speed boxes: They are a bit hard to find and quite expensive even 2:nd hand.
The swap requires a new shorter trans axel as well, otherwise i think it`s a direkt swap.

A 2:nd hand 5 speed gearbox could be the easiestt (read cheapest) way. There was a guy here on the forum that was scrapping his M5. Maybe he still has the box? MAke a search on the board.

Colud be only the sychros though.....


2,762 Posts
Discussion Starter · #4 ·
Thanks for all the help once again - i've been on holiday hence a bit quiet.

It appears the box has been taken apart before - this could be a source of the problem, as the car is suppossed to only have had 140,000 Kms on it, and I have receipts and MOT's going back to 768kms (nearly new), so am reasonably confident it hasn't done much more than that (the interior is also in good condition) so wouldn't expect to be having problems with the box otherwise.

The grinding is a definite grind, not thuddy, and is only present if you are changing gear quickly and from high revs - it sounds like the clutch is not disengaging fully. But it is only on 3rd gear, although it is a bit lumpy going into 2nd, but nothing to worry about. I haven't tried changing without clutch but call me soft as i'm a bit weary of doing it!!

If it is just the synchros can this be changed easily or is it just worth replacing the box?

I think a replacement may be better - there is also some evidence of some rather shabby work on the brake pipes and a few bits and pieces, as it looks that the worst of the cars treatment has come in the last 2 years and 30,000kms of its life (after the main dealer service history was not maintained) although it did such low mileage for the first 10years of its life I suspect it may have been treated harshly when driven from cold as it was a show car for a car dealer and was fitted with a reasonably large sound system seeing around 4,000 miles a year for a good 6 years in a row.

Now for the idiot question - i know someone who is breaking a left hooker 3.6, so how will I know the box is ok (the car is not drivable as the engine has been sold already) ?

I think I may leave it with a 5 speed box, if going 6 speed is going to cause me extra problems, as I'm not feeling too flush and have a tyre bill coming soon as well as my first inspection 2 service where I plan to tidy any shabby bits on the car that the service discovers.

I want to get this car 100%, as it has been my dream to own one since I was about 12 and first saw one, and my old man had a e28 525i at the time. I'm prepared to spend on it, and eventually I want to get all of the bodywork up to original condition as well. Just gotta sell my 535i sport auto to pay for some of the work - anyone interested? I have got all receipts and MOT's for the last 60,000 miles, and it is in fine running form, and has been such a loyal dependable workhorse for me, and I have always maintained it regardless of cost. It has just had two new rear tyres, and all drive belts replaced, and is fitted with 235/40/R18 alpina style rims. I can provide photos if needed!!

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