[Michal]

Hi guys - new to here.
I have low milage e90 330i pre LCI, car is great but since it has been city car, 1st, 2nd and 3rd gear are worn and hard to shift :-(

First qs is whether this transmission can be repaired?
If not I am looking for new pre-owned one and getting to the point that there are tons of GS6-37 transmission - some of them are even refurbished.
I am not sure whether I need to stick with Realoem compatibility or there are more compatible gearboxes, eq from N53 engine or from M54?
Or can I get whatever GS6-37BZ (I don't even know what BZ stands for) or also DZ would be okay?
Then there are sub fixes such as TJET, TJEP, BEP etc, which confuses me even more.
Is there some sheet that can bring me light in this or does anyone here has the great knowledge?
Many thanks

[AdrianE36]

I'd try a fluid change first to see if that makes a difference since it has low miles. Mine spent time in Chicago then Brooklyn for a few years before I bought it and and shifts just fine (151K miles).

Edit: I just noticed that I replied exactly 3 hours later lol.

[Michal]

Originally Posted by AdrianE36

I'd try a fluid change first to see if that makes a difference since it has low miles. Mine spent time in Chicago then Brooklyn for a few years before I bought it and and shifts just fine (151K miles).

Edit: I just noticed that I replied exactly 3 hours later lol.

Thanks, I just changed the oil day before I wrote my post.
It has not changed a thing 😕

[MOD.Works]

Are you sure the problem is the gearbox?
Sometimes worn gear levers and bad bushings make it difficult to change gears.
Or a problem with the clutch. Or bad engine and gearbox mounts. Often the cause is something other than a bad gearbox. Especially if the problem is changing gears, and there are no strange noises coming from the gearbox

BZ gearbox is for gasoline engines and DZ for diesel engines. Different ratios.


I rebuilt the shifter. All new and an E60 550 short shifter that I have shortened a bit and it is perfect.


https://vm.tiktok.com/ZMFmoyHam/

[Michal]

Originally Posted by MOD.Works

Are you sure the problem is the gearbox?
Sometimes worn gear levers and bad bushings make it difficult to change gears.
Or a problem with the clutch. Or bad engine and gearbox mounts. Often the cause is something other than a bad gearbox. Especially if the problem is changing gears, and there are no strange noises coming from the gearbox

BZ gearbox is for gasoline engines and DZ for diesel engines. Different ratios.


I rebuilt the shifter. All new and an E60 550 short shifter that I have shortened a bit and it is perfect.


https://vm.tiktok.com/ZMFmoyHam/

Thanks for your reply.
When the transmission is cold sometime you can hear metal click when shifting from 1st to 2nd.
When gearbox warms up it is almost 100%.
Clutch I will be replacing soon.
5th and 6th gear is shifting smoothly like whipped cream.. The lower gear the worse..
Do you thing engine/gearbox mounting could cause this? I would say so if it did not depend on trans oil temp...
Also you mentioned gear levers and bushing - I feel no looseness in there.. Maybe I am wrong?
Thanks

[MOD.Works]

If you get a sound when you change gears, it sounds like a synchromesh or otherwise a gearbox fault.

Usually, bad engine or trans mounts make it difficult to change gears under hard acceleration.
When driving slowly and shifting poorly, the problem is usually the clutch or the gearbox. The problem with the clutch is detected in 1st gear or reverse. The other gears work a little better, although the clutch doesn't release properly.

[Michal]

Originally Posted by MOD.Works

If you get a sound when you change gears, it sounds like a synchromesh or otherwise a gearbox fault.

Usually, bad engine or trans mounts make it difficult to change gears under hard acceleration.
When driving slowly and shifting poorly, the problem is usually the clutch or the gearbox. The problem with the clutch is detected in 1st gear or reverse. The other gears work a little better, although the clutch doesn't release properly.

That is the same conclusion I came to.

Now let's get back to my original question.
Compatibility of GS6-37BZ - whether they are all exchangable no mater of sub fix or not, does anybody know?

[Twix]

The BZ will have different ratios than the DZ, as diesels have a lot more torque and less RPM. You should be able to get new synchros put in no problem