Is my Transmission Broken?

[sapote]

First, Sometimes while shifting into first or second, you think its in gear, you feel it pop into the de-tent, but its not. Happened a few times lately. I noticed it last year and chalked it up to a really sloppy shifter due to bad bushings. I threw in a new set, it feels great, but same issue.

Second one, Sometimes when shifting, seems any gear, you feel a slight "kick" in the shifter. Not a gear grinding noise at at all, almost like something hit something in the mechanism. Shift fine, but you feel and sometimes hear a knock. Once again its not a gear grinding noise, but rather a single bump.

A worn or broken gear-position-detent pin/roller (the GPS attached to this) might cause this, so you might want to remove this detent and try again to see if it engages smoother. With the detent removed you might need to keep the shifter in place to avoid the gears pop out though, but of course this is a temporary for a test. The detent is mounted on the left near the rear of the tranny. It pushes again the main shift rod.

[heinzboehmer]

Yep, both those things sound normal for these gearboxes. Some seem to do it more than others but it's been there to some degree on all the cars I've been in.

I've replaced every single part that's replaceable (shifter, bushings, detents, springs, clutch, flywheel, etc.) in an effort to try and improve the feel and, while the overall feel has gotten better, those two things your describe are still there.

[cobra]

My transmission used to do some pretty weird stuff back in the day. Double clicks... popping out of 2nd gear... overall clunkiness. I switched to Amsoil MTF transmission fluid and it's been much much better ever since. It's not a perfect smooth transmission by any means, but nothing I'd consider abnormal anymore.

[Thoglan]

The double step into first and second gear is 'normal' for these. The synchro design on those gears makes them a bit of a pig to change through especially when cold and if you get the timing off. Some wear will be related to the issue. Don't let it grind, everytime it grinds you are making it worse. Don't let the clutch out if the gear doesn't fully engage. Take it out of gear, let the clutch up, blip the throttle, and select the gear again.

There are a few people that can service the gearboxes but it almost always makes more sense economically to just buy a used one.

[Lee_Enfield]

This may not help, generally my experience has been, the higher the revs, the easier the shifts. Change the fluid every 30k miles, and while bushings could be the culprit, i'm guessing lack of fluid changes may be the cause here? go change the fluid with proper spec oil see if that improve the situation. This ain't no S2000 gearbox--it's clunky and takes some input to operate...

I forgot to mention I did do the fluid last year, maybe 3000km ago? Used BMW fluid.

[PSUEng]

This may not help, generally my experience has been, the higher the revs, the easier the shifts. Change the fluid every 30k miles, and while bushings could be the culprit, i'm guessing lack of fluid changes may be the cause here? go change the fluid with proper spec oil see if that improve the situation. This ain't no S2000 gearbox--it's clunky and takes some input to operate...

[Lee_Enfield]

Hello,

I have been driving my M3 a bit now that its on the road, and have a few questions. There are a few odd things that I occasionally notice when shifting.

It is a Manual with around 220000km (136000ish miles)

First, Sometimes while shifting into first or second, you think its in gear, you feel it pop into the de-tent, but its not. Happened a few times lately. I noticed it last year and chalked it up to a really sloppy shifter due to bad bushings. I threw in a new set, it feels great, but same issue.

Second one, Sometimes when shifting, seems any gear, you feel a slight "kick" in the shifter. Not a gear grinding noise at at all, almost like something hit something in the mechanism. Shift fine, but you feel and sometimes hear a knock. Once again its not a gear grinding noise, but rather a single bump.

I am Dreading a bad gearbox. My understanding is these are not serviceable, and a toast box is a new box.

Any input?