I just wanted to post up a success story of a failed CVT rebuild. At about 110K miles the CVT died on our 2002 R50 and left my teenage daughter on the side of the road. My first reaction was to just sell it for scrap/part it out.

After calming down a bit, I started to look into rebuilt trannys and even a manual swap. Neither were cheap options, and I really didn't want to sink a lot of money into an older car with 110K miles on it. I had just put on new rotors/pads, new electric fan, new struts/mounts, and changed all fluids and didn't want to risk losing any more money. I decided I had nothing to loose by tearing it apart and seeing if I could possibly fix what I had myself. ...a manual swap was my back-up plan.

After tearing into it, it was immediately obvious that the belt was destroyed. The metal bands completely broke on one side and the metal links were scattered all through the tranny. When they did, one of them made its way between the ring and pinion gears. Although it chipped the edge off of a couple of the teeth it really wasn't too bad...maybe 1/4" chip on the edges of four or five teeth. Replacement gears were hard to find and expensive ($1,000+) so I decided to just grind the rough edges smooth and take a chance on them. I found a belt for $300 from AliExpress. For that price I was willing to take a shot at it working with the chipped gears...much cheaper than a rebuilt tranny or a manual conversion.

Long story short; its all back together and driving like it should. Total investment: $300 for belt, $22 for new filter, $40 for fluid and a couple days of work.

I have read a lot of stories saying the CVT cannot be rebuilt. Time will tell how it holds up...just about 100 miles on it so far...but it seems to be working fine.

Only regret was not putting in a new belt sooner. I knew it was just a matter of time before the belt failed. If I had, I wouldn't have damage on the gears. ...which could have been a lot worse.

 

Great news, hopefully it lasts and you have no more trouble. I think the same can be said for Midlands GB's. I was speaking to a local salvage and he said its a matter of not flogging them and 50k kms oil change on the midlands.

 

Congratulations!!
Keep the oil fresh and enjoy!!
Glad to hear it worked out for you!!

 

Makes me think this is a lesson, replace the belt at 100K miles.

REGARDLESS of what MINI says.

Motor on!

 

Great job! I'm hoping I have the skills to fix something big when it breaks in my car.

 

Good to hear...we have a 2004 Cooper with the CVT. At 55k miles we have a ways to go, I have had the fluid changed twice now and we don't beat on it (that's what I have the S for ). Hopefully it lasts a while longer, but I do wonder....

for those who care, I found this on AliExpress:
http://www.aliexpress.com/item/90108...8.0.331.n2e9gN

 

You, sir, are a national treasure. Perhaps you should go into business! Hopefully people will stumble upon your thread and start rebuilding their CVT's instead of junking/parting out their R50's.

While you had the subframe out I hope you put the purple powerflex control arm bushings in there and checked the ball joints (4) for looseness. If not, it's something you can collect the parts for and drop the subframe for again. Once you've done it, you realize that it's not that hard is it?

Val

 

It's his daughters car - doubt she'd approve of anything with powerflex in its name if she knows what they're famous for!



Man, hope your daughter actually likes the mini instead of just using it for transportation. I need to find a girl who likes Minis!

Motor on.

 

We need pics on how to or DIY. Congrats on the fix.

 

My wife bought hers somewhat on a whim and loved it so much I had to get one. No, you can't have her but women like her are out there. Just don't look too hard and you will find what you are looking for. It's a zen thing.

 

it's a zen thing! LOL!

we all are hopeful of finding that right one!!

 

Yes, my daughter loves the Mini. I'm a fan too. I have always been a Jeep guy (currently own 3) but this little guy is growing on me. I'm thinking of getting another one for myself!

The rebuild wasn't too hard...just time consuming. Most of the time was spent trying to figure out what all needed to be removed to get at the tranny, and then trying to figure out how to split the tranny case once I had it out.

 

I have a pretty extensive set of tools, but didn't use more than a standard set of wrenches/sockets; 10mm, 13,mm, 15mm, 16mm, 17mm were the most commonly used sizes. A set of screw drivers, metric hex keys (allen wrenches), etc. were also used. The only thing I'd consider "special" was a 1 5/8" and a 1 13/16" socket to get the primary and secondary nuts off. ...I'm sure they are actually metric, but I didn't have, nor could I find metric sizes that large locally. ...they're not really "special", but most people probably won't have sockets that large. I used my air impact wrench a lot too, but I wouldn't say it was required. ...it just helped speed things up. A floor jack, jack stands (front), car ramps (under rear tires), and a bottle jack were also used. The higher you can get it the easier it will be to work on.

I started by removing the tires, bumper cover/bumper, struts, brakes (tied the caliper up out of the way), axles, inner fender liners, air cleaner box, battery/battery box. I then loosened the sub-frame, dropped it just a little and then unbolted the steering shaft and power steering reservoir. Supported engine/tranny and then lowered the sub-frame a few inches. I then removed all electrical connectors on the tranny, disconnected the cooler lines, and then all the bolts holding the tranny to the engine. Next I unbolted the tranny mount and lowered the engine/tranny so the whole assembly was tilted to the driver side a few inches. I was then able to separate the two and drop the tranny down. ...I needed to push the sub-frame outboard a little to get it to clear.

These two videos show how to tear down most of the tranny:

Tear Down Video:

Mini Cooper CVT Valve Body Installation:



The rest of the tear down is fairly intuitive once you've done the above steps. After it was all apart, I spent A LOT of time cleaning everything. Its critical that you get all the little belt pieces out of there. Don't forget to flush the cooler lines too.

This manual should give you an idea of how to get at the rest of it:
http://www.lib.ucdavis.edu/dept/pse/...T1F-040323.pdf


If you're lucky, there will be no damage to the gears. I had minimal damage and was willing to roll the dice on it working without replacing the ring and pinion gears. I had some chipped edges that I smoothed down with a dremel tool. If there is extensive damage, you'll need to replace the gears.

Now is a good time to inspect/replace the 6 friction disks. I wish I would have just replaced them because I was in there...mine looked "OK" but did understandably show some signs of wear. European Transmissions had them for about $75. At the time, I wasn't sure if any of this was going to work, so didn't want to spend any more than I had to (I was already gambling about $360 for the belt, filter, fluid at this point.) Now that I know its possible to rebuild, I wouldn't think twice about replacing them. ...lesson learned.

One tip: use tape to label all the connectors and put the bolts in sandwich bags as you remove things. Write down where you removed the bolts from on the bags with a marker. Makes reassembly much easier.

I know that's not the best write-up. If I could figure out how to post pictures I could add some. ...wish I took better notes during the process, but that's the general idea of whats involved with this. I'll try to add more details later.

I'd be willing to answer any questions if anyone wanted to try this themselves.


2002 Mini Cooper CVT overview:


Inside Mini Cooper CVT Drive Belt Pulleys:


CVT Parts:


http://www.aliexpress.com/item/90108...811383353.html


http://www.coastmotorwerk.com/mini-cvt/

http://europeantransmissionscom


http://www.amazon.com/Valvoline-804751-6PK-Continuously-Variable-Transmission/dp/B00DJ4FGIK/ref=sr_1_1?s=automotive&ie=UTF8&qid=1429965886&sr= 1-1&keywords=valvoline+cvt




Other write ups that may be useful at this link. Many of them describe how to remove a lot of the stuff that needs to come apart to get at the tranny.
http://www.pelicanparts.com/techarti...Tech_Index.htm

 

Agreed! ...if the belt breaks, there will potentially be 450 steel segments floating around in your transmission wreaking all sorts of havoc. Only one set of the steel bands (there's one set on each side of the belt) broke on mine. A lot of the segments separated from the belt, but about 3/4 of them stayed connected to the still intact other 1/2 of the belt. Its almost impossible for none of them to make their way into your ring and pinion gears or drive pulley gear. I consider myself extremely lucky that I had only minimal damage to my gears. My daughter stopped right away and shut the car off. ...don't know if that helped?

The gears are VERY expensive to replace and hard to find. That's the main reason I decided to reuse the damaged gears...not something I would normally recommend.

If you can do the work yourself, replacing the belt and maybe the friction clutches before you have a failure would potentially save you $1,000+ in damaged parts later. A belt, filter, friction clutches and fresh fluid would run just over $400. The rest is labor. Pretty cheap insurance considering the alternative. If you aren't able to do it yourself though, not sure it would be worth it. I would imagine labor would be very expensive.

Not sure at what mileage Id recommend doing it at. Id probably guess around 80K miles (130K Kilometers) or so. I know some fail prior to that and some go much longer. Id rather do it too early than too late.

While your in there, its also good time to inspect/replace brakes, struts, ball joints, etc since they all have to come out anyway.

 

That was my intent. I couldn't find anything saying it had been done before. Most either shelled out big dollars for a rebuilt one, junked it or swapped in a manual. Wanted to let people know it was possible to do yourself.

 

Congrats!
This thread is good news for the rest of the CVTs still on the road heading towards self-destruction.

 

Very good to read, I cringe every time some buys a cvt.

 

Thanks again for the post and for making the very obvious observation that rebuilding these things before they explode might be a great idea if one plans on keeping their MINI for a while. This was a real "dooh" comment for me as I wasn't thinking along that line concerning my wife's MINI, which she wants to drive forever. I had pretty much resigned myself to waiting till it died to do something about it. Now I think now I will look at having it rebuilt at about 80k.

 

Wow! That is awesome. Should definitely post up a DIY for those looking to do the same if they run into this issue. Definitely keep the thread updated with the progress of it as well. You seem very DIY capable, so if you ever do need any help with things make sure to check out our DIY Tech Articles. Keep up the good work!

-Luccia

 

How awesome !!

 

Hi, I also had a CVT failure that I'm in the process of re building. All of a sudden my moms 03 mini r50 started leaking mass amounts of transmission fluid from the bell housing. My buddy and i pulled the transmission out and found it was leaking from the input shaft seal. We replaced the input seals, and both the output seals since we were in there. We installed the transmission, re assembled the car, went to pull out of the drive way and the seal started leaking again. So for the second time we pulled the tranny. This time we inspected the issue much further. What it boiled down to was the input shaft had some play and when it spun the play was enough to let the fluid shot out. So this time we started to break down thw cvt, when we split the bell housing it was obvious the bearings that hold the shaft in position were broken, some were laying on their sides, others had exploded. The part actually fails pretty often. Its called the needle bearing, and is only 30$ to replace. However, when the bearings failed they made grooves on the input shaft. The grooves are located at the base where it's supposed to hold the shaft straight. I need to replace that shaft as well. You would think that because the bearing fails they would have input shafts available. Well...Here's the ***** of it all. NO ONE SELLS THE INPUT SHAFT. I've been searching for 2 days now. I started with the dealers, then bmw, then local tranny shops, today I spent a day calling anyone I could find on the internet that sells cvt parts. All roads failed. The closet i came to the part was with AsianTransmissions in GA. USA. They have the shaft but want to sell me the planitary gears with it. And they want 500 bucks for the set. I don't need the set. Plus I've already spent 750 on labor and parts pulling this thing twice. I paid 3500 for the car 6 months ago. Now I'm 750 bucks into trying to fix it. It's not worth another 500 just to gamble on if it will even ever work again. I need to find someone that has the input shaft for sale. I made videos of the removal process both times. As well as the tranny tear down. If someone can point me to where I can buy a input shaft I'll record the rebuild and re install. Also I'll post pics up here to help others in the future. This car is real cool and I would love to salvage it. It's going to be a big hit to me financially if I have to part it out. Digging the forum. I hope someone on here has the knowledge of where to locate the part I need. Thanks in advance.

 

Maybe a salvage yard has a mini you could dig into?

Sorry, sounds like you're in a bad spot.

 

I'm at the local yard that would let me dig into the tranny every few days. Unfortunately they never have any r50s. Also most the other yards wouldn't let me tear into the tranny. They would want to sell me the whole thing. And a cvt transmission for the mini is 1500 at a salvage yard. When most normal transmissions are 350. So buying complete is not an option. I appreciate the thought tho. I think I'll look into ordering the part from over seas. If I still can't score one. I'll see how much a machine shop would charge me to repair or duplicate the shaft. In the end, that's probably what I'll have to do. I'm in not in a rush so I'm sure eventually I find a way. Thanks again little joe.

 

Check the R50's Auto 2002-2006 and the R52 MINI Cooper NON S Convertible 2005-2008, they all shared the CVT. www.car-parts.com for salvage.

 

Hi MikeGordon, how is your car going many months and miles after the cvt rebuild?
I just finished removing my cvt from my 2004 mini and I'll follow the links and infos you provided in this post. I wanted to know how the car in which you rebuilt the cvt was going