So, I was enjoying my R53 after a recent head gasket and cylinder head rebuild job, noticed it was leaking some type of fluid pulling over to my drive way, pictures attached.
First I thought it's engine oil, but it smelled like transmission fluid.
The same afternoon, I was waiting at the light, when light turned green, I shifter to 1st gear, let clutch go (smoothly of course), I heard a not so loud "thud" sound and car doesn't move. I can shift it through all the gears, but doesn't engage with the engine.

Towed the car home, and drained the tranny fluid. I got around 1 Qt of transmission fluid its pretty dark. Is my transmission toast ?
I don't think it is clutch because I never heard of clutch being "open" when failed? Also the clutch feel is just fine.
Also heard absolutely no grinding sound or any kind of trouble from the transmission before this incident
Any thoughts guys?

 

Without closer inspection pictures, it's really hard to tell.
But, the Getreg 6 speed is pretty stout.
I'm wondering if you have an LSD or not, if not, it almost sounds as if you're looking at the drive side axle that has pulled itself out of its splines.
That would be my next step in diagnosis. (Besides, axles have to come out for any transmission/clutch work)

 

BlwnAway, man!, I am literally blown away! Thank you! Thank you! (I would like to give you hug , I almost started looking for a used tranny in the car-part.com)

No LSD, but the driver side axle popped out. Please see the picture. The retaining pin may have worn out ? I guess I should remove the axle and inspect it before popping back in?
So now that explains why it all started with a fluid leak!

 

Inspect everything really well, there has to be a reason for it.
If you are able to pop it back in, order yourself a new one to swap in soon as possible, including a housing/case seal (yours will probably be damaged)
​​​​​​Esp if you see no clear reason it popped out, it simply shouldn't. usually the culprit is a locking ring (the small C clip wire that goes on the inserted end of the axle) not being there anymore, and the suspension cycled just far enough to allow it to come out.
Or, it wasn't pushed in far enough to begin with. (But you didn't mention replacing or re-inserting it for some reason)
Just make sure it does go in all the way, new or old one, the joint cup should ride only a few mm from the case

 

the pass side axle is held in by 3 bolts on a bracket attached to the engine block if i remember right. if that bracket is tight / undamaged the axle should not be able to back out.

it does not have a clip holding it in like the drivers side i dont think. someone correct me if i'm wrong here.

check to see if the bracket came lose. dont forget to top up your trans fluid. the leak happens as the axle backs out.

 

His was the drivers side.
But yes, both sides have the keeper rings.

 

Thanks again BlwnAway and thanks ssoliman for chiming in

Only the driver side axle (the short one) came out. Passenger side is intact

No, I haven't done any work on the axles or transmission recently. The only work I did on the axle was few years(4-6 years ago) ago when the rubber cv boot was torn, I replaced it myself.
Had to do it twice as the boot I replaced first started leaking again. I did take out the axle to replace the boot, but it has been few years and I drove thousands of miles after that

So , this may be a case of worn out seal or the snap ring? I remember installing that C clip on the axle end when I did the cv boot job.

Should I get this seal before starting to get the axle out? https://www.fcpeuro.com/products/min...co-23117550058

 

I believe that's the wrong seal, it sound like that is for the transmission output shaft, you want the drivers side (in case they are different) transmission/inner axle seal:

https://www.detroittuned.com/mini-tr...le-seal-inner/

 

Good catch! Your correct. I need to change my order.

Btw, do you happen to know what's holding the axle c-clip to the transmission? is it the axle seal ?
I didn't take out the axle from tranny yet, but wondering what's holding it together so install is a snap, but it stay put? Thanks again

 

Not sure, haven't had my transmission/diff apart to that extent.

Normally it's a groove machined in the spline bore, or the rings position actually exceeds the depth of the gear itself.
Because of the design of the clip, I'm inclined to think it's a groove machined into the inner spline.

 

ahh ok drivers side. drivers side does have a clip. passenger side held in by bracket, no clip. or i should say that's what it looks like on this one from my sons 2006 r50. Going this job currently.

 

i've also heard mini mod (is it mini mod or mod mini, i'm so dyslexic) confirm the same. no ring on pass side

 

Lol...
Maybe, it's been 6 months or so since I've done one, and at my age, I'm lucky to remember 6 hrs ago.

 

Correct

Since I was taking it out anyway I shot a picture of it. It's from a 2006 R50 but its nearly identical to the R53. The snap ring actually clamps into the diff.

 

@BlwnAway ,@ssoliman and LukasH, Thank you guys! I truly appreciate your help.

It's so nice of you to snap a picture to help out a fellow forum member. I got all the parts (gear oil, rubber seal and C-clips basically). going to take out the axle tomorrow. Will find out what happened
I was chatting with Chris at FCP euro and he thinks the axle can pop out of the diff, if you make extreme left or right turns. That could be my case, I do some hard U turns when I pick up and drop off my son at school.I may have to stop doing Us and do some 3 point turns

Another possibility is that when I did the CV boot job, I may have shortened the travel inside the CV boot. Either way, I will post what I find out this weekend

 

I've never heard of the "corner too hard" thing, and considering the amount of track time that these cars are a part of, it seems that it would be well known.
But, I'm a street guy, so... maybe?

Glad we could help

 

I think the mystery is solved!
It seems to be a combination of my cv boot job and the hard U turn on a side street

Check out the pictures , the right side boot that's near the transmission side is too compressed. I remember when I replaced the cv boots, I pushed all the air out of the rubber boot so the vacuum is pulling it together like a spring.
Of course the c-clip is all screw'd up because it was spinning inside the splines.. Hopefully it didn't damage the differential where it bites to.

I could try to re do the boot , but wondering if I should just get a new axle and get over this mess?

 

I would get a new axle. If you look closely you see the spline ends are not sharp but chuwed up where snap ring inset begins. Compare it to my picture above and notice the difference.

 

Good observation! I thought it was machined to be like that
Time to get a new axle I guess

 

LukasH, Thanks for your help!
Quick question- your axle in the picture - is it genuine MINI or aftermarket ?

 

These contributions offered some tremendous insight!
The only thing I might suggest when reinstalling / installing the driver side axle - To insure the snap ring/circlip seats home; After installing the axle end into the trans and while guiding the hub over the outer end - *Give the hub a nice solid push so the axle/circlip are nicely engaged within that circlip groove.

Just an added thought.
Best of luck!

 

Genuine MINI with ~106k miles (178k kms)

Jep, that's how I do it as well.

 

Thank you Here2Go and LukasH for the suggestions!

I also wanted to say this - I had a completely worn out top Engine mount (that has been replaced recently and my cabin is super quiet now) that caused too many problem with the car - it broke my exhaust header at the flexible portion of the header as the engine kinda swings back and forth when you accelerate and slows down, serious vibrations inside the car etc. Not sure if the engine swings caused the axle also to come out. That could be a 3rd factor in this puzzle.

 

A bad motor mount would definitely be the reason for the axle popping out.

 

I absolutely agree with you. It's unbelievable how much damage a worn out motor mount can do to this car. I believe most people,I am included : ), overlook the importance of motor mount on this car thinking it's just a vibration damper.

Anyways, I wanted to shed some more light into the problem that I experienced, so it helps someone

The first picture below is a comparison of the old and new axle, in it's fully stretched position
On the right is the old one where I replaced the cv boot, with all air pushed out and with a very good vacuum seal. Noticed the length difference. The vacuum on the cv boot pulls the axle together and so it stays short. On the other hand the the axle I bought, OEM GKN, has a breather cut (2nd picture) in the boot so it holds no vacuum and you can stretch as much as you want and it stays at that length. Now I do not know if this is a new thing because, I don't remember seeing a breather on my original axle CV boot before. Not sure if that will cause any grease leak in the future. may be this is an improvised design who knows?

3rd picture is the opening on the differential, just so whoever interested can see where the C-clip latches into

Hope this helps