After gearbox rebuild, 4º gear jumps, need help... - The Unofficial BMW M5 Messageboard (m5board.com)

Nuno Miguel · 2nd April 2005, 01:38

Hi, i got my gearboxbox "rebuild", the job was consisted in replacing the 2º, 3º and 4º syncro rings, all bearings joints and some minor parts. the job was done by a experient mecanic. The problem is that, i went to test the today, and... for all gears shift very well, but at some moment the 4º gear, jumped... (with out scratching) and so on, since then at aprox 90/10km/h it always jumps(only the 4º)... my mecanic was very surprised... and said that it only could be two things, 1º the compresion springs that he didnt change (he already made the order) and the 2º could be the GEARSHIFT ROD JOINT that he changed, but the new one from BMW was slight diferent from the original one... bmw said it has been improveed (???)

Honestly... what do you guys think it is... nothing inside the gearbox? (hi hope ...)

It never hapen befor, the gearbox was fixed because i couldnt shift 3º gear without scratching.

Nuno Miguel · 3rd April 2005, 12:01

no one?

DaveW · 5th April 2005, 01:40

IF you are looking for a wild guess and that's all it would be without looking at your Gearbox it could be a detent spring in the selector shaft that is not forcing the ball bearing against the slot to hold it in position.

At best this is a wild guess - at worst I have no idea whatsoever but suggest you get it looked at again by a gearbox specialist or good independent BMW specialist like Munich Legends etc.

Dave.

Nuno Miguel · 13th April 2005, 17:11

Quote:

Originally Posted by DaveW

IF you are looking for a wild guess and that's all it would be without looking at your Gearbox it could be a detent spring in the selector shaft that is not forcing the ball bearing against the slot to hold it in position.

At best this is a wild guess - at worst I have no idea whatsoever but suggest you get it looked at again by a gearbox specialist or good independent BMW specialist like Munich Legends etc.

Dave.

Ok... sorry for the delay...

After cheking all the gearshift sistem (external to the gearbox) and changed compression springs... news are still bad

4th gear jumps no more, but instead it does not engage at medium revs, at high revs it does very well, in acelaration 3th»4th from 120km/h (in3th) to the redline no problem, at speeds slower then 120km/h (in 3th) engage 4th is impossible... it doesnt stratch it slimply doesnt complete the movement, when you try to shift it the knob starts o shake, at speeds below 30km/h shifting is possible again... my mecanic wont open the gerbox again until he gets the bmw repair Manual and said to drive the car like that to see if there any improvement.

Any opinions?

(will open another tread...)