Greetings, all. It's been a while, but I've worked my way through a lot of cars before finally bagging a very needy 2013 R56 Mini (base hardtop model with a manual transmission). I'd sworn off BMWs recently, but this is not QUITE breaking that promise to myself!

Anyway, the first problem (and the reason I could buy the car for $900) is that it doesn't move. The previous owner (actually, her stepfather) said she was JDA (Just Driving Along) and there was a fairly horrible noise, and she coasted into a parking lot with no ability to move the car at all.

With the wheels (all) in the air, I can turn one wheel, and the other one doesn't move. I can shift through the gears from the cockpit with the engine running without engaging the clutch. Idling in 6th gear, the wheels do turn (at different speeds) and can be stopped by hand.

I'm thinking it's time for a new transaxle. Of course, I'll include a new clutch kit and rear main seal while I'm in the area, and of course look for other issues with the clutch fork, bearing, etc. as well.

Anyone out there think there's any chance that I don't need a new (used) transaxle? I can pick up a 68,000 mile boneyard transaxle for around $200 locally, and am thinking about a Sachs clutch kit.

I'll be posting other questions in the not too distant future, I suspect... this car is a "target rich environment" from a repair perspective, but I think it'll be a nice enough (third) car when I'm done with it...

 

I've made a lot of progress on this project car, but would still love to get a second opinion on the transmission to make sure what I'm seeing can't be anything other than a blown transmission, in case it could be something related to "just" the clutch (clutch fork, throwout bearing, clutch itself, etc.)

Thanks!

 

How many actual miles on the car? I am not convinced it is the actual transmission, but could be the clutch... But, since you have to drop the transmission to replace the clutch, I would get everything needed to perform a clutch job. Then, once the transmission is out, you will be able to see if it is the transmission or just the clutch. If its just the clutch, then you already have everything needed to replace it and be done. If its the transmission, then get a decent used box and reinstall with all the new clutch parts, and enjoy.

 

Makes sense. I was thinking the lack of coupling between the two wheels was an issue, but I'm a Mini noobie and am not sure that the transaxle acts like a limited slip differential in "a lesser car"...

 

Sorry, I meant to include that tidbit... The differential is a open.

 

Ahhhh, thanks - that's the info I needed. I agree that it's likely that the "big problem" could be the clutch itself. I'll have to drop the transmission to find out, naturally... Hoping it's not a broken fork or other tidbit I don't have on order (I have the Sachs kit on the way, and I guess I need to get that tranny out so I can find out if I need to schlep over to the boneyard to pick up a "new" transmission or not).

And just to clarify (before I reinstall a blown tranny)... the way my transmission acts is normal for an R56 (with a totally blown, "open" clutch) without a limited slip differential, correct?

 

From what I can remember, an open diff will act as you have described.

 

Well, I think I'm a happy boy. I got the transmission out (along with the subframe and a few hundred of its closest associates). Really not a horrible job - I'm glad this wasn't a car that had spent too much time in the frozen north.

The transmission seems to do what a transmission should - I could insert a long screwdriver through the axle holes, and spin the transmission - at least in most gears - it got difficult as I lost mechanical advantage in the lower gears.

Then I pulled the clutch. Oof. I've seen some worn out clutches, but I have to think that this one's cooked enough that it would stop pulling the car altogether. The rivets are worn down significantly (can't be sure how much taller they used to be).




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I just took a closer look, and what I thought were dusty rivets in the darker holes don't have any rivets left at all... yikes. So every other rivet is missing altogether.



The main reason that I was thinking that the transmission was shot was the description from the PO, albeit one from his significant other's daughter. She claimed to be just driving along and *bam* the car lost all forward drive.

Just throwing it out for the collective wisdom of the Mini world - do you see any reason I shouldn't just put in a new clutch and call it a day? It's only an N16 car, and I promise it's not gonna get tracked. ;-)

FWIW, the flywheel looks fine - no gouges or grooves, so I think it'll clean up OK. I'll be putting in a new RMS while I've got it apart (oooh, I would hate myself if I didn't and a week later saw oil dripping out of the bellhousing). ;-)

 

That clutch disc does look cooked, but somehow still ahs some meat left to it...

While you have the gearbox out, crack it open and have a look inside. Perform a visual just to see if anything looks out of the ordinary. There is a magnet tucked into the side of the housing - would be a good time to clean it up and see if any gear teeth are missing.

I forgot that the base models have a solid flywheel. Those can be resurfaced, so might be worth it to have it cleaned up for the new clutch kit.

 

I was encouraged by the fluid that I drained during the removal. It was clearly dirty, and in need of change... but I didn't see anything shiny at all in the fluid. I'll take a look at the process for disassembling (and reassembling / sealing) the transmission.

I'll take a closer look at the flywheel clutch mating surface to see if there are any irregularities, and proceed accordingly. A new (base model, solid...) flywheel is pretty cheap, so maybe I'd just swap it out if I did find something concerning. FWIW, the only other clutch replacement I did was on my 200,000 mile Jeep Cherokee, without resurfacing the flywheel... it's been perfect since then (about 50,000 miles, including some pretty heavy duty operation off-road).

 

Pulling it apart isn't that difficult. On reassembly, just need to make sure you have the correct sealant that is resistant to gear oils. Do a google search for R56 LSD installation, and you'll see how it comes apart.

 

Thanks - I think I found the video you referenced. Some "interesting techniques" shown in it (including pressing on a bearing pushing on the needle bearing cage and not the inner race, using an impact wrench as a torque wrench, using a steel hammer on mating surfaces, etc....) but a great resource even so.

The only reference to the sealant is "non-hardening". I do have a tube of Permatex automatic transmission RTV, but I see there's a "gear oil RTV" as well so that's got to be the right one.

That all said, I've been thinking about what kind of internal (manual) transmission failure could cause my symptoms, and am coming up with nothing. With nothing but gear-to-gear contact from the input to the output, it seems like it's either going to turn, or not turn... rather than "turn, but with no real torque". The only thing I can think of that would allow for shifting through all of the gears with the clutch "engaged" (worn as it is...) is if a few of the teeth on the differential gear are sheared off, but still tall enough to transmit enough torque to turn the wheels when they're dangling. Of course, then I'd expect to see some sort of metal chunks in the drained oil and I'd guess some odd noises with the transmission in gear under no load. Maybe I can take a swing through the case with a flexible magnet to see if I can pick up anything. Any shavings or chunks (no matter how small) would indicate a traumatic failure inside the case.

But I really hate to think about reinstalling this lump and finding out afterwards that it's got a fatal flaw (especially when I have a local tranny with half the miles lined up for around $200...). I'll probably split it!

I'm going to be "off the job" for a while due to a visit from an old friend, but will be going back in a week or 10 days. Looking forward to my first test drive on my "new" R56!

 

Shifting through the gears with the engine off isn't really telling you anything, other than the shift mechanism is good. The only part that "MIGHT" be busted could be one of the differential gears, but not sure how that would go along with the behavior you've mentioned...

I used this stuff when I installed my LSD, and it seems to be not leaking:
https://www.permatex.com/products/ga...et-maker-3-oz/

 

I was able to shift through the gears with the engine running. With the wheels on the ground, no lurching or attempt to move at all. With the wheels in the air, they'd spin, but I could stop either one by hand.

That (I think) tells me that the gears inside the tranny are meshing and everything that should be turning is turning... but I am thinking about those differential gears as well, and can almost imagine a failure mode that would result in the kind of thing I was seeing.

I suppose splitting the case isn't a bad idea. Even if the "no spin issue" isn't in the case, there could be other fatal flaws in there that would make a "new" $200 transmission a great idea.

I did order a tube of the same Permatex "gear oil RTV". So I suppose I'm committed. ;-) I'll try to do a video on the teardown and inspection of the transmission. It won't be a master class, of course (I haven't worked on many manuals over the years - I suppose because they don't break). ;-)

 

Learning as I go here - just saw that the crank bolts (which have to come out to replace the rear main seal) are one-use bolts. Or are they really? Sounds like it, with the spec (that I could find) being Stage 1, 6 ft/lbs, Stage 2, 22 ft/lbs, Stage 3 +90°

They're not too spendy (about $3 a pop x 6 bolts from FCP Euro), so I guess I should just order a set - or is it common practice to just crank 'em down?

 

I have one more question. I recall taking out the slave cylinder, and was surprised that it was under tension (from the shift fork?) for maybe 1/2" of backing the nuts off the mounting bolts. That is, the slave cylinder was pushed out of its bore as I loosened the nuts. That struck me as a little excessive, but maybe it's normal for a Mini?

I just examined the throwout bearing and pressure plate. There were signs that the throwout bearing had spun on the pressure plate finger tips, though the bearing itself didn't feel too bad at all (maybe it's got a lot of drag under pressure). Speaking of which, I guess there is a reasonable amount of pressure on the slave cylinder piston "at rest", pushing the engagement rod out (toward the clutch fork)... more than I would have expected. I guess the throwout bearing is turning any time the engine is (I'd always picture the throwout bearing as just sitting there waiting for the clutch engagement to spin). But maybe that little bit of pressure pressing on the clutch fork is enough to disengage what's left of my paper-thin clutch disc?

FWIW, I did some research on the subject of whether or not a throwout bearing should be in contact with the pressure plate fingers all the time... or not. The answer is yes. ;-) Apparently, "back in the day" (think muscle cars) the throwout bearing was not designed to spin full-time, and would wear out if it did. So they designed the system to have long throws on the slave cylinder to take up the slack and THEN press the throwout bearing into the pressure plate fingers, disengaging the clutch. But in the last couple decades, apparently bearing tech has improved to the point where it makes more sense for the bearing to ride on the pressure plate fingers all the time, rather than being jarred from a dead stop to full speed with every tap of the clutch pedal.

Just trying to understand why the car felt like the clutch was fully in when I bought it... I could shift through the gears with the engine running and the clutch pedal out. FWIW, the clutch pedal is dead firm with the slave cylinder disconnected and fully extended (I believe that's as it should be). Pushing in the slave cylinder piston take a reasonable amount of force, and it will automatically extend to full travel as soon as you release it (again, I believe this is correct).

 

Well, pretty sure that the problem was only the clutch at this point. Here's the "new vs. old" profile.. yikes!



Also, I decided it would be prudent to split the transmission and have a good look-see inside to make sure nothing was amiss. I was amazed at the tiny bit of black sludge captured by the magnet, and how clean and pristine the inside of the case looked.





I carefully shifted through all the gears, spinning the input shaft with only my fingertips, and looked for any sign of chipped or missing teeth, loose bearings, etc. All looked like a 10,000 mile transmission. It'll be going back in shortly! I used the correct "gear oil RTV" to seal the case, which looks to have worked perfectly (just a tiny squish showing all around).

 

Just to close out the saga, the problem was indeed "just the clutch". I'm still fairly amazed at how much pressure it took to mount the clutch slave cylinder, but the car shifts and handles like it should. The clutch is now "perfect".

I also replaced the front struts and mounts, front lower control arm compliance bushings (while the subframe was sitting on my garage floor), the cooked rear tires, and a host of aesthetic and detail items. The car now looks good, shifts great, rides and handles "like a Mini", and at a "chump change cost". I'm thrilled...

 

Nice! Glad it all worked out and you didn't have to buy a new gearbox

 

Thanks... The things that threw me were the PO saying that there was a loud noise followed by no drive, and the fact that the front wheels didn't move in opposite directions when spinning one (in neutral). I'm assuming that the PO's report about the failure wasn't entirely accurate, and that there was just enough drag on the front brakes to keep the diminutive Mini open differential from transferring the spin from one axle to the other.

Now it's onto the remaining punchlist items... A new windshield and hood. I think both are good candidates for a DIY video...