Yesterday I made a trip of 100 miles all by highway.
All the way was done at a speed of 75 m/H in cruising speed.
A couple of miles before arriving at my destination, I reduced my speed behind a truck and when possible I tried to pass it.
When I was overtaking the truck (6th gear, at 80 m/H and throttle full pressed) my gear just popped out to neutral.
Then I put the 6th gear again, full throttle again and after a few seconds it popped out again. From that moment on, whenever I put 6th gear and torque on it, the gear always is popping out.
This doesn't happen with any other gear.
The 6th gear works perfect if I'm on a flat or downhill road on any speed.
The 6th gear comes out and engages perfectly when required (no clutch problem or it not detectable)
No gearbox vibrations, noises nor strange behaviors at all.
I have 75k miles, and the clutch was changed on 60k miles.
The gearbox oil was changed on 30k miles and 60k miles, but I have not checked if the current level is correct.

Tomorrow I'm going to take it to an indy BMW shop wating for nothing worst than:

1) Low gearbox oil level
2) Problem with shift linkage adjustment
3) Problem with the engine support

If there is a synchro being worn out or internal problems, I'm not ready to spend the money on it right now so it will be sleeping a long long time.

Any advice or experience with this will be really very appreciated.

 

When I had a similar "popping out of gear" problem (5th gear), it turned out to be a worn bushing on the tranny linkage. Could also be the shaft linkage, which is splined, was mated wrong when re-assembled. Gotta move a bunch of stuff to get at it, but not that difficult.

 

Thank you for your comment

I received a call for the BMW indy shop some minutes ago.

The tech said that oil level is not related with the 6th speed pop out behavior and from "visual inspection" the linkage seems to be OK.
He said too that surely the problem is the that the synchronizer for the 6th gear is worn.
He ruled out that it is a problem of a internal retainer or something like this because in these cases all the gear on that side should be failing: 2nd, 3rd and 6th too.

He offered to disassemble the back cover of the gearbox to check the gears of the 6th but said that if he can not see anything there, he should remove the box and disarm it completely to remove the worn gear. I must find another equal gearbox to replace the worn part or, I should request the exact piece to a local turner (no too much MINIs in my country for extract gearbox nor parts).

I'm not trying to deny the problem but I'm going to pick up my MINI and go to another tech shop for another check...

 

The second tech (multi brand indy shop) says that yes, it could be a worn gear but they should check first the basics after trying to open the gearbox:

- problem with shift linkage
- broken motor mount

He was very honest and told me that they have repaired other gearboxes for other brands (Mecedes Benz, Audi, Jeep, Range Rover) but never for a MINI so he would need to have a diagram of the shift cables and they will give me the result in the same day.

Now I'm looking for this on Google, I have not had any luck until this moment. If someone can guide me to this info (pics, explanation) it will be more than welcome.

I saw that in Pelican Parts, there is only the guide for shift cables replacement for the R53, not for the second generation.

 

Last night gearbox fluid was changed.

The previous one was somewhat burned (expected) but in general in good condition. There would not seem to be any contamination on it and the amount was as expected (no leaks).
After using it for a while, I went to the highway and forced all the shift to 3500RPM. All shift OK except the 6th gear that after a few seconds continues to jump to neutral.

I took advantage to do other tests:

- I forced the 2nd and 4th gear (same line as 6th) RPMs up to 4000RPM, working perfectly (without vibrations nor noises).
- 6th gear only jumps if you are applying an important amount of torque after few second, once you release the throttle (with a finger on the shift ****), you can feel that the shift "returns" to its place instead of continue trying to pop out

No luck with shift linkage diagram or location for the R56 on google to share with the indy shop, I will try the tech can find it for me this night

 

I was experiencing the same thing. The rubber bushings that secure the shifter's box to the chassis were incredibly soft and worn resulting in movement of the shifter under load in 6th. I replaced the shifter with a CAE ultra shifter that mounts directly to the chassis with solid mounts. Changing the shifter made a huge difference, but I still occasionally experience the 6th gear pop out, though much less frequently. I am going to replace the upper gearbox mount and motor mount this weekend to see if that eliminates it.

Definitely take a look at the rubber bushings that secure the shifter housing to the chassis.

 

Great info Scotty!
Thank you so much for sharing this.

I want to give a chance to this option since last year I installed a NM torque arm bushing insert for a few months and I had to remove it since the engine and pedals vibrated too much (really).
This was more than one year ago, but may have affected in some way to get to this situation (I really hope)
Please let me know any news from your side on this change.

I will leave my MINI at the indy shop tonight and I will comment this to the tech.

I will keep updated this thread on what they found (or not)

 

I left my MINI at the indy shop last night.
The tech will inspect:

- Shifter mounts
- Shifter - Transmission linkage
- Transmission mounts
- Engine mounts

All of this trying to find something with adjustment problems

I will have news in less than 48 hs

 

Still with no news.
Trying to calm my anxiety and do not call to the shop

 

UPDATE

Indy shop tested all the exterior parts:

Shifter mounts
Transmission linkages & mounts
Engine mounts

All is in perfect condition.

Now the transmission is out and being verified internally by the techs

 

Still no news from the transmission indy shop.
Waiting for the call...

 

I hope you are back on the road again, tough situation.

 

Well, the transmission is still out of the car.
There is a problem with the 6th gear and the 6th gear syncro sleeve.
The people at the indy shop prefer buying these parts (new or used in perfect condition) over sending these pieces to a local transmission factory to be done.
My transmission is a Getrag GS6-55BG and here I can't find any GS6-55BG from any MINI or other car to buy the entire transmission nor by parts.

The problem is that I can't find a replace kit for the 6th gear. I can find a lot of offers for 2nd gear kit and for bearings & seals kti but nothing for the 6th.

Any help or advice to find these parts will be really appreciated since my boy is out of the streets since around 2 months...

 

I could find a second hand transmission.
My first idea was to install directly this transmission but the tech said that opening and taking the necesary parts (at not additional cost) is a better option because we don't know the real internal condition.

1) The 6th gear is worn and will be replaced (gear + syncro)
2) The 2nd gear has signs of wear and it would be convenient to replace it (gear)
All other parts are tested and 100% OK.

Clutch is OK but after checking it the tech said that is a good chance to change the clutch release bearing since it is not working 100% OK (it doesn't spin as freely as expected).

3) Clutch release bearing will be replaced

The used transmission will be here in 10 days

 

UPDATE

6th gear replaced
Synchronizer replaced
2nd gear replaced
Clucth release bearing replaced

All gear working OK, smoother than expected

 

I’ve just recently been having this problem as well and it seems that you were able to replace the 6th gear + synchro and that fixed it. I was wondering what the total cost was for doing that? I’m trying to find a 6th gear plus synchro for my r60 but no luck so far