[dom1973]

Help!

So, my second gear synchro has gone in my 2013 (September) 525d F10 and cannot find a replacement. (No BMW part centre stocks them, BMW specialist cant find one and gearbox specialists cant find one). So, I have found a whole rebuilt gearbox at a good price (compared to others). The original gearbox has a code GS6 17EG . The replacement is GS6 47DZ (2012). I have heard that the 5 series is compatible with the 3 series and Z4.

The question is, will the the replacement GS6 47DZ be compatible with my car? (The bloke selling and fitting it says it will, but I'm nervous).

Any advise appreciated.

Cheers

[Apples12]

Have you tried contacting zf directly?

[dom1973]

Thanks Apples, good idea. I've sent them a message.

[bfleming]

Backtrack a little here... your car would have come with GS6-45DZ from the factory, not that other number you quote - not sure where you have that from?
You have to stick with like-for-like replacements here, which I know from first hand experience. Different numbers mean different ratios, which in turn mean that the engine ECU won't be happy - it has the gear ratios coded in there, so knows what the road speed / engine speed ratio should be. If it sees this ratio outside one of the 6 it's expecting to see, it cuts back on power. I went through a world of pain on my E90 EfficientDynamics as someone replaced the GS6-45DZ with an older-yet-more-robust GS6-37DZ box. It's a direct fit, complete with the neutral position sensor that start/stop needs, but the car was never happy.
The GS6-45DZ box is more expensive that others as it's in demand / relatively rate secondhand, but trust me, that's the one you want.
Lastly BMW doesn't sell parts for these boxes (as you now know). A rebuild at a ZF specialist would be an option though.

[Apples12]

Just out of interest, what exactly happened to your gearbox? In terms of symptoms etc? Don't hear of the 8hp box going kaput very often at all!

[bfleming]

It's not the 8HP, it's the manual GS6 45DZ that we are talking about. It's very common that reverse gear goes missing in that box.