1st and reverse gear popping out of gear.

[FungShui]

Hello,

I need help from my ZHP aficionados. First and reverse gear has been popping out of gear in the last month. I am positive the gear is fully engaged. The odd part the behavior is inconsistent for example the shop bucking the car by letting the clutch out fast in 1st gear without it disengaging. In some cases, it will pop out of gear under light throttle load and other times its fine at 3400 RPM under medium throttle. No issues with 2nd to 6th gear is fine under full throttle.

An audible pop sound [although no grinding sound] can be heard when the transmission decides to disengage.

Does anybody have any ideas that would cause this?

I'm really hoping I don't need to replace the transmission.

Car history/debugging can be found here:
* (May 2012) - Transmission fluid replacement completed at 108,358 [Redline 75-90 Gear Oil]
* (August 2012) - Transmission fluid replacement completed at 110,425 [OEM MTF-LT-2 fluid] - Shifting was too notchy with Redline and went back to OEM fluid
* (Mid April 2021) - Shop installed Autosolutions short shifter, Rouge transmission mount, Guibo replaced, and Driveshaft CV joint
* (~ First week of May) - 1st & Reverse gear popping out of gear
* (~2nd week of May) - Issue occurs more frequently
* (May 19th) - Car sent to shop and is able to reproduce the issue
* (May 27) - Autosolution sent out a new shifter and still popping out of gear

Next steps:

* Reinstall OEM shifter

[FungShui]

So the shop has informed me that 1st gear is still popping out of gear after swapping to the stock shifter. Their recommendation is replacing the transmission. :crying

I found one dealership that is selling remanufactured 6 speed transmission for $3,000.

https://parts.bmwnorthwest.com/p/BMW__330i/RP-REMAN-6-gear-transmission-GS6-37BZ---THEG/43697292/23007532498.html

The other option is try find a transmission on CL or ebay but I'm not sure if its worth risk of getting a bad unit. Is there a reputable BMW dismantler that I should contact for parts?

[pedro2u]

If it comes to it, I do see one on the web in Minnesota for $799 includes freight: https://recyclebmws.com/bmw-e46-zhp-transmission-6-speed-manual-zf/

Might be worth a call.....

[BMWCurves]

A bit of a gamble and I'm talking out of my butt, but have you tried seeing what prices are like for local yards that might have ZHPs?

[BH93]

A bit of a gamble and I'm talking out of my butt, but have you tried seeing what prices are like for local yards that might have ZHPs?

Don't know if junkyards really keep tabs on zhp vs non-zhp... but OP you're probably better off doing a rear m3 conversion with the LSD diff and 6 speed off an m3 while you're at it :)

[BMWCurves]

Don't know if junkyards really keep tabs on zhp vs non-zhp... but OP you're probably better off doing a rear m3 conversion with the LSD diff and 6 speed off an m3 while you're at it :)

My local wrecking yard does, but YMMV.

Is an M3 transmission plug and play with an M54?

[pedro2u]

looks like our 6MT was also used in the 5 Series, might broaden your search, but I've read even the Z4 too

But here's what Realoem said assuming I've got the right part number:

23007532498

Exch. 6 speed gearbox
GS6-37BZ - THEG
From:03/03/2003To:-Weight:43.500 kgPrice:$3801.30
Supersedes:
23007523981(03/03/2003 — 06/18/2003)
Part 23007532498 was found on the following vehicles:
3' E46   (09/1999 — 08/2006)
5' E60   (12/2001 — 02/2005)
5' E61   (10/2002 — 02/2005)

[BH93]

My local wrecking yard does, but YMMV.

Is an M3 transmission plug and play with an M54?

If you use the rear end + drive shaft + transmission I believe everything just bolts right up to the M54

[FungShui]

If it comes to it, I do see one on the web in Minnesota for $799 includes freight: https://recyclebmws.com/bmw-e46-zhp-transmission-6-speed-manual-zf/

Might be worth a call.....


A bit of a gamble and I'm talking out of my butt, but have you tried seeing what prices are like for local yards that might have ZHPs?

Thanks for everyone's input!

I tried to purchase the remanufactured transmission from the BMW website and was later notified that it was NLA. I had a feeling it was NLA but I figured it worth a try.

However, I was able to source a ZHP transmission from Sacramento. I dropped off the transmission off at the shop earlier today.

The clutch and pilot bearing will be replaced while the transmission is out. :)


If you use the rear end + drive shaft + transmission I believe everything just bolts right up to the M54

Yes, I believe Derbo did something very similar with his ZHP.

[FungShui]

Happy to report the car feels great after the transmission swap and new clutch.

[fredo]

That’s great. Good to hear you are back into business.

[BMWCurves]

Happy to report the car feels great after the transmission swap and new clutch.

Nice! Sad it was something as big as the transmission, but at least it's now fixed. So what was the actual failure point? And how long had you had the car before this started happening (miles/years)?

[t.er]

Yeah geez, what a freak issue - sucks that you had to do a full swap but it is what it is. I think I heard Daniel (kakashi169) had this as well when he had his manual swap at first

[FungShui]

That’s great. Good to hear you are back into business.

Thanks!


Nice! Sad it was something as big as the transmission, but at least it's now fixed. So what was the actual failure point? And how long had you had the car before this started happening (miles/years)?

I had the car for 11 years from ~86k miles and now with ~133k miles. This was my DD until 2015 and was retired to weekend duty when I purchased my motorcycle. My fleet expanded again and became the extra weekend car. It is adult driven with intention of being a forever car. Most of my shifts are before 3k and I do not track the car. No burn outs or clutch dumps launches. Transmission fluid flushed twice as maintenance before issues arose.

I'm not sure what exactly went wrong within the original transmission as I did not want to pay for a tear down and failure analysis. The stock shifter engagement was fine and was not sloppy despite the age and miles. I had some extra cash burning in my pocket and decided to upgrade to the Autosolution's SSK. After the SSK was installed, I noticed it was sitting heavily biased towards the right. Shifting into 1st gear was physically positioned as if it was in 3rd gear. The shop told me transmission detents within the shifter are worn and can present itself as such.

The car drove well and the shift engagement was excellent when I got the car back and following day in the backroads. 1 week later, it gently popped out of the reverse while backing out of the drive way. I did not give it a second thought as I was unable to reproduce the issue again. Later in the day while commuting back home it pop out of 1st gear and again was not able to replicate the issue. I took a mental note of the events and had an uneventful drive home.

On week two, I shifted into first pulling from a red light and hear pop sound (like the pop sound made with your mouth or finger). By this time it had enough momentum and speed to get into 2nd. The next light I accelerated [~35% throttle input] from 1st. While approaching 2,8XX RPM a startling auditable pop is made [no grinding noise] and found the shifter in neutral. I pull over to take a look at the car and did not observe anything abnormal or out of place. To make a long story short, that day I was able intermittently reproduce this issue only in 1st gear. 1st pop was also random and not a function of throttle input or engine RPM speed. The shop also observed this as well. Oddly enough, 1st gear remained in gear even when they repeatedly bucked the car with a quick clutch release. 2nd to 6th gear did not have any issues.


Yeah geez, what a freak issue - sucks that you had to do a full swap but it is what it is. I think I heard Daniel (kakashi169) had this as well when he had his manual swap at first

Yeah, the shop which specializes in E36 and E46 and transmission supplier never heard or encountered his issue before.

[t.er]

Yeah, the shop which specializes in E36 and E46 and transmission supplier never heard or encountered his issue before.

Which shop is this? I try to do all my own work but when something like a rear wheel bearing goes out, that's not something I want to deal with



Sent from my SM-G781W using Tapatalk

[BMWCurves]

Huh...that's very strange for something in the transmission to go out like that at low miles. I wonder if the shifter had anything to do with it? Somehow resting in the gear was not fully seated and wore out the gear...position somehow?

Do you still have the Autosolutions SSK in there with the new-to-you transmission? If so, is the position the gears still offset from neutral? When I first had my UUC SSK installed, it had some offset issues that turned out to be them sending the shifter assembled backwards.

Also for some reason I thought you had only had the car for a couple of years, congrats on 10+ years of ownership! Remind me, what else is in the stable currently? I got my motorcycle license over the pandemic and have been lusting for something like a Husqvarna Svartpilen 401 :drool

[FungShui]

Which shop is this? I try to do all my own work but when something like a rear wheel bearing goes out, that's not something I want to deal with



Sent from my SM-G781W using Tapatalk

Performance Technic. They work on all generations of BMW but they built a strong reputation supporting the E46 platforms. Seems they also support Porsche and Audis but I rarely see anything besides bimmers. They had a evergreen Z3 M Coupe at the shop last time which looked similar to the one below except some oxidation on the hood.
38141


Huh...that's very strange for something in the transmission to go out like that at low miles. I wonder if the shifter had anything to do with it? Somehow resting in the gear was not fully seated and wore out the gear...position somehow?

Do you still have the Autosolutions SSK in there with the new-to-you transmission? If so, is the position the gears still offset from neutral? When I first had my UUC SSK installed, it had some offset issues that turned out to be them sending the shifter assembled backwards.

Also for some reason I thought you had only had the car for a couple of years, congrats on 10+ years of ownership! Remind me, what else is in the stable currently? I got my motorcycle license over the pandemic and have been lusting for something like a Husqvarna Svartpilen 401 :drool

The shop thought it was the shifter as well. The issue was still present for the following cases:

Reinstalled the shifter
Installed a new Autosolutions shifter that was sent to the shop
Reinstalled stock shifter

Huge thanks to Ron @ Autosolutions who participated in a couple debugging video meetings and sent out a replacement shifter to the shop. His customer service is outstanding. In case somebody hasn't read the full thread, the shifter was not the cause of my problem.

Yes, the Autosolutions short shifter is in the new transmission. The shifter is no longer biased to one side and sits pretty close to stock. :) The shop also measured the AS SSK throw and found it was 2.5mm longer with the "new used" transmission vs the original.

I have a 2010 Triumph 675, Z4 M (see signature), Tacoma X-Runner, and MK7 Golf TDI as DD. I'm actually in process of consolidating the fleet to start hopefully start a overland build.

The Husqvarna looks like a fun bike and the price to entry is pretty good. Triumph Street Triple and Suzuki SV650s are good alternatives if you like naked/streetfighter bikes. My SV650 was the most fun bike by far and equivalent to the Miata of car world.