[vtown]

Posting my experience, as I searched for this issue and found 0 hits while I was dealing with this. Wondering if anyone else has had an issue. If not, Maybe it will help someone searching for an answer in the future.

I purchased my 2013 335i msport 6MT in December of 2015 as a CPO car with ~36k miles. The car was virtually flawless.

Shortly after delivery I began to notice a scrapping /light grinding noise at lower speeds (<35mph) regardless of gear selected (I.e. Identical noise whether in 2nd,3rd,4th gear). It almost sounded like I was dragging a piece of debris under the car. Going faster than about 35 mph the sound was overcome by road noise (runflats ) First I thought it was a brake caliper dragging but I jacked up the car and any brake drag was so minimal that I ruled it out. It got a little louder with mileage racking up.
I brought it to my local dealer and asked them to check it out. I has shocked that I got the car back with them "unable to reproduce issue" .
Drove it another month untill it pissed me off enough to bring it back in. This time I insisted on a ride along from the shop foreman. Driving in 2nd or 3rd, alternating on the gas and engine braking makes it present itself. Tech ackknowledges the noise and listens with his head near the gear shifter.
He asks: "is this an xdrive?"
Me: "nope".
Him: "you need a new transmission"
Me: "gasp! Is this common?"
Him: "we've had a few. usually it's the xdrive transfer case though"
Me: "double gasp!"

So anyway, it seems to be the output shaft bearing, not really the tranny guts themselves, as the sound is attached to the driveshaft speed, not engine speed.
They don't service this kind of thing anymore, they just swap major components. Took them a few days to get the new tranny, and one or two days to swap it. It was fully covered, I wonder what the price out of pocket would be.

[donkey]

I haven't had any issues with an output shaft bearing (I think) but I do think the input shaft bearing is on the way out. If I let my clutch out in neutral it sounds like there's a couple of marbles rolling around in the tranny. The car only has 3,000 miles on it and I rev-match, etc. so it's not like I'm constantly beating on the tranny to cause it to fail.

There's also a super pleasant vibration noise that comes from the shifter at 3,000 RPM. I'm probably going to take it in over the next few days and hope they can fix it.

Yay for warranty!

[lo_xyooj]

dang that cant be a cheap fix...good thing it was still under warranty.

[Paz1]

http://f30.bimmerpost.com/forums/sho...l+transmission

[rak299]

I don't have a disassembly manual for that transmission, but I think vibration in the shifter means the problem is more likely to be needle bearings in the main shaft (top shaft is split). That can be caused by an incorrect preload when the rear seal is pressed in. If that is the case, front and rear bearings could be damaged also. You want a replacement transmission, rather than a dealer repair. I would expect new and remanufactured would be equally good.

[F30_SixSpeed]

damn that's scary. My 6MT is buttery smooth.

[XKxRome0ox]

Originally Posted by pgarbul1

http://f30.bimmerpost.com/forums/sho...l+transmission

Anyone experience the 2nd gear synchro issue in a newer f30? I think I am experiencing the same symptoms as those in the quoted thread
I have a 2016 328i 6mt
With 6500 miles

[raqautle]

Originally Posted by vtown

lt was fully covered, I wonder what the price out of pocket would be.

When I was working at parts I remember someone having a problem with their car, I think transmission (AT), and we went and ordered one then a tech found out the problem was a simple fix. The bosses were complaining about a 12grand piece of hardware just sitting there.

[CalCarNut]

$12k for our 8AT?!?!?!

[donkey]

Originally Posted by rak299

I don't have a disassembly manual for that transmission, but I think vibration in the shifter means the problem is more likely to be needle bearings in the main shaft (top shaft is split). That can be caused by an incorrect preload when the rear seal is pressed in. If that is the case, front and rear bearings could be damaged also. You want a replacement transmission, rather than a dealer repair. I would expect new and remanufactured would be equally good.

Thanks for the info

[donkey]

Originally Posted by F30_SixSpeed

damn that's scary. My 6MT is buttery smooth.

For now

[vtown]

Originally Posted by pgarbul1

http://f30.bimmerpost.com/forums/sho...l+transmission

Thank for the link, I guess I missed that one. Yes, MT failure. However is a different root cause. That is for syncro failure whereas I had output shaft bearing failure.

[rak299]

synchro failure or rear bearing failure will not cause vibration in neutral.

[AudiA4]

Originally Posted by XKxRome0ox

Anyone experience the 2nd gear synchro issue in a newer f30? I think I am experiencing the same symptoms as those in the quoted thread
I have a 2016 328i 6mt
With 6500 miles

Yep. My 6MT was replaced under warranty at about 24,000 miles for a bad 1-2 synchro. I test drove three 6MT cars (lightly used) and TWO of the 3 had this problem.

[XKxRome0ox]

those of you who've had the transmission replaced for the bad synchro issue, can you post any of the repair orders or whatever document you received from the dealership?

i just dropped off my car again for the 3rd time to be checked out for the 2nd gear grinding
and i told the SA and tech foreman about what i had found on the forums... and of course their response is they can't rely on what's posted on the internet
and they cannot pre-diagnose the problem and have to be able to duplicate it
that's all understandable
but i think it'd help to actually show them repair orders that cite the 2nd gear synchro problem

[Polo08816]

Originally Posted by raqautle

When I was working at parts I remember someone having a problem with their car, I think transmission (AT), and we went and ordered one then a tech found out the problem was a simple fix. The bosses were complaining about a 12grand piece of hardware just sitting there.

Originally Posted by CalCarNut

$12k for our 8AT?!?!?!

I think it's around $6500, not $12000 at least not for a remanufactured transmission from BMW.

http://www.realoem.com/bmw/enUS/part...&q=24008645377

https://getbmwparts.com/parts/index....&siteid=214672

[AudiA4]

Originally Posted by XKxRome0ox

those of you who've had the transmission replaced for the bad synchro issue, can you post any of the repair orders or whatever document you received from the dealership?

i just dropped off my car again for the 3rd time to be checked out for the 2nd gear grinding
and i told the SA and tech foreman about what i had found on the forums... and of course their response is they can't rely on what's posted on the internet
and they cannot pre-diagnose the problem and have to be able to duplicate it
that's all understandable
but i think it'd help to actually show them repair orders that cite the 2nd gear synchro problem

Why would it be a question once they drive it? My BMW tech didn't even make it around the block before he said, "Yep, bad synchro. Solution: new transmission."

If you have a bad synchro, it's bad every time. Mine was easily replicated, consistently, with an aggressive 1-2 shift at high rpm. The synchro couldn't keep up.

[XKxRome0ox]

Originally Posted by AudiA4

Why would it be a question once they drive it? My BMW tech didn't even make it around the block before he said, "Yep, bad synchro. Solution: new transmission."

If you have a bad synchro, it's bad every time. Mine was easily replicated, consistently, with an aggressive 1-2 shift at high rpm. The synchro couldn't keep up.

Can bad synchro have intermittent grinding?
I would estimate that I feel it about 10-15% of the time when shifting into 2nd
Dealer tech always says cannot duplicate

[AudiA4]

Originally Posted by XKxRome0ox

Can bad synchro have intermittent grinding?
I would estimate that I feel it about 10-15% of the time when shifting into 2nd
Dealer tech always says cannot duplicate

I'm a bit surprised it could be intermittent, unless the exact scenario isn't consistent. Mine behaved perfectly fine when babying the car around, but as soon as you wound it in first and tried to quick shift to second, "Crunch!"

Either way, if it happens 15% of the time (or so), it wouldn't seem it would take very long to replicate.

[Paz1]

Can anyone post a video of this ? Curious to see

[Coaster4428]

This is kind of eerie - i just bought a 2013 M3 w/ 35k miles and 3 months in, I have had the exact same issue - it started grinding in 2nd gear and then was grinding in all gears. I took it in, and the dealer said there was 'internal failure'. Needless to say - they had to replace the transmission, clutch, and flywheel. BMW has denied helping out to pay for the defective transmission - which really disappoints me (cost me $10-12k). The car is out of the 4 yr warranty, but well within the 50k miles limit. My concern is this might be a broader issue as I've seen a few other posts with similar issues. Please share w/ others and let me know, as I will also be following up w/ FTC / Consumer Affairs to asses if this is a broader issue. Not a fan of how a global performance automaker treats it's high end customers.