I'm planning on finally replacing my OEM mechanical LSD with a Quaife unit this winter while my MINI is tucked away. I just wanted to check what other proactive part changes I should be doing while the trans is out. Transmission only has 57,000 miles on it. Relatively low. I want to at least visually inspect my clutch friction material to make sure it's not on the brink of having no friction material left. Other than that, here's my list:

-replace clutch fork if stress cracks present
-replace sh1tty plastic pivot pin for the fork
-throwout bearing guide tube
-I'd be a fool not to replace the plastic throwout bearing with new so I'll add that

Conventional teaching would say replace all seals. Including the engine's rear main seal, driveshaft seals, and transmission input shaft seal. However, I think this may be totally overboard for a transmission with only 57,000 miles.

Thoughts everyone?

 

I'd do the clutch anyway....the discs are pretty cheap...labor is done... And get it now before it does get thin and slip... Might save you a flywheel...
If the bushings in the front end are still rubber, I'd do them...heck most of the work is done.....save you later, and get a bump in handling.

 

FCAB's got done a couple of years ago with Powerflex. Good point about cooking the flywheel surface when the clutch does start to go out.

 

We did our Quaife install two-ish weeks ago. The car only had 33k miles on it so I didn't replace anything while I was in there. Clutch disks for the JCW cars aren't particularly "cheap" at $150 for just the disk. You can probably re-use the pressure plate and don't need to resurface the flywheel so while cheap for a "clutch replacement" it's still another $150. Since I do all the work myself I opted to wait on the clutch. After having the whole thing out the first time I'm pretty sure I could do a clutch job in a long day if I have a helper/tool gopher.

About the only thing in there to replace is the engine rear main seal, transmission input shaft seal, throwout bearing, clutch release fork, TOB guide sleeve, and clutch fork pivot. I believe the axle seals you can do with the trans in the car without too much work. Looking on Pelican parts gives the following parts breakdown...

$158 - Clutch Disk
$70 - TOB
$26 - TOB Guide Sleeve
$46 - Clutch Release Fork
$5 - Clutch fork pivot

That's $306 on stuff that "might potentially break". On the other hand it would really suck to have to pull the trans again just to replace the clutch fork pivot. Hard to say what is worth it from a preventative maintenance perspective. Sounds like Way always replaces the pivot, release bearing, and release fork when he does a clutch job.

If you want to replace the itemized things above I wouldn't blame you. However, I wouldn't mess with the engine rear main seal and trans input shaft seal. Without the proper tools to remove/install you can easily do more damage than good with those seals. They should be good for 150k miles easy.

Top tip on the diff install... make sure the trans is on it's end when you go to separate the casing. As in the input shaft is pointed straight up and you pull straight up on the case half. Make sure the diff/reverse gear stays in the lower part of the casing. My trans case was sitting at an angle when I separated it and the diff and the whole reverse gear assembly came with the part I was holding . That was a huge PITA to put back together. Don't forget new bearings for the diff. Oh and you can remove the subframe without removing the front bumper but it does make it easier. You don't have the put the car in "service mode" though. Let me know if you have any more questions while the install is still fresh in my memory.

Also, a few of the bolts are torque to yield (stretch bolts) and are supposed to be one time use. I didn't replace them because I wasn't thinking ahead and the dealer was closed on the weekend. The transmission hasn't fallen out yet If you want to do it "right" then look through the Bentley and all the bolts that have a torque spec plus additional 90 degrees should be replaced.

EDIT: If you don't have some universal joints for your socket set (in 1/4, 3/8, and 1/2) sizes do NOT start the transmission removal because you won't be able to finish it without those universal joints. There are some bolts you can barely get with a universal and would never get with just straight extensions.

 

Thanks for the tips. Funny you mention the rear main seal. My dad and my step-bro recently did a rear main seal job on my bro's Neon and it ended up being a total waste of time. They used a tack hammer to put the new seal in place My dad usually is detail miser being a hot rod builder, but man he really must have wanted that Neon job done. Back to leaking again! I've heard of one of our engine trainers at work using a piece of PVC pipe with success. Pretty good idea I must say considering the price of the BMW special tool.

I have a u-joint for 3/8" but thanks for recommending them for the other sizes. Looks like I need a E-torx bit set too.

It would really be nice to put in a new lightweight flywheel/clutch assembly but that OS Giken unit is just way too expensive for what it is. It really sucks someone like Fidanza can't come out with something competitive. A single disk clutch shouldn't cost $1800!!!

 

I bought this tox set a little while ago after reading around on GarageJournal. Seemed really popular/highly reviewed. Sure beats tool truck pricing.
Has all the torx bits I will likely ever need.

The PVC seal installer idea is fairly common and a great idea if you can find a size that fits. Lots of main seals you can buy where they come with a disposable seal installer to help with the installation.

you could probably get away with just a 3/8" u-joint. Most of the hard to reach bolts aren't particularly tight. There are two on the top of the trans that are really tough to get to. We did it from the driver side wheel well with probably 24" of extensions. You can't see the bolts from the top of the engine bay. And one of those on the top of the trans facing the drivers side is a regular hex bolt and it's a starter bolt. The Bentley failed to mention that one in their transmission removal but if you go to the starter replacement section they do talk about it.

Unfortunately STX doesn't allow for flywheel replacement so we're stuck with the DMF I'm not looking forward to having to replace that flywheel. It's like $700

Oh and I was able to sneak in some auto-x runs in the mini this weekend after the diff install. It was absolutely amazing. Right up until a coolant hose came loose (fortunately not off)

 

I probably won't get around to doing the work until December or January. I've had the front sub-frame out before so that'll come out pretty fast this time.

Yea, the Bentley manual helps up to a certain point. Then it's time to get creative

Did you re-use the driveshaft c-clips?

 

Seems like only the drivers side driveshaft had a c-clip and I didn't replace it. The passenger side just slid right out. I didn't remove either driveshaft from the steering knuckles. Don't forget to keep the CV joints "level" and don't get them too angled. Don't want the ***** to pop out

For the passenger side...
You can move this around because the control arm is disconnected. Just undo the two bolts holding the center support bearing to the block. What I did to support it was to just use one of the two center support bearing bolts and loosely bolted the center support bearing back to the block but in the lower hole. So the top hole of the center support bearing is bolted to the lower hole on the block. This moves it down and out of the way and supports it without having to tie it up or anything.

For the drivers side...
I ended up removing the whole suspension/knuckle as an "assembly". Once the subframe is out the only thing holding the knuckle/shock in is the three nuts on the shock top mount and the driveshaft. Don't forget about the two connectors for the wheel speed sensor and brake sensor. Oh and you'll have to remove the brake caliper but that's just two easy bolts. Use a prybar to pop the driveshaft out of the transmission then undo the three top nuts and drop the whole thing so you can get it out of the way. It's heavy though so put a jack under it and it'll be great to have a helper. If you're just on jack stands this frees up a lot of space to work in the driver side wheel well which I found handy. Also keeps you from having to remove/replace that axle nut which is torqued pretty good and staked in place.

My experience with the mini transmission removal was that there wasn't any one particular part that was difficult... there is just a lot of stuff to remove so it does take kind of long. Figure out some way to support the trans from the top and it'll make your life a million times easier. The trans is probably ~90 lbs and it has a cast eyelet in the top you can tie something to.

Oh and the shift linkage connections shown in the bentley were different than that on my car. They're just ball/socket type connections so just get a little leverage and pop them off.

 

I was thinking of using a transmission scissor style jack to support the transmission from the bottom. Did you just use an engine picker and chain from the top? Seems like that might be a better idea now since I'd have more room to use my hands to put the transmission back into place.

 

You'll probably get the transmission off with a scissor jack but you'll never get it back on

If you don't have an actual transmission jack (I don't) then you have a few options. HF sells an engine support bar which would probably work. It has two "hooks" so you could use one to support the loose end of the engine (I used a jack and 2x4 under the oil pan) and the other to kinda raise/lower the transmission.
http://www.harborfreight.com/1000-lb...bar-96524.html

The Bentley tells you to loosen the passenger side engine mount. They already have the intake manifold piping off so it was easy for them. I couldn't get to the bolt without a lot of work so I just left it and the engine still tilted down enough for me to get the trans off. I don't think the mount was damaged but I'll be keeping an eye on it. You do have to make sure to remove the part of the transmission mount that bolts to the transmission. I believe it was 4 14mm bolts. That gives you space so the trans can clear the frame when you pull it off the engine. Only tilt the engine as much as you have to in order to get the trans off.

Or you can do what I did. I don't have a cherry picker and didn't feel like borrowing a friends so I used an understanding wife and a 2x4. Taking the trans out is easy. Put one end of a long 2x4 on the passenger side strut tower. Hold the other end up in the air and tie a rope through the eyelet on the trans and around the 2x4. Have your helper hold the rope taught then reach in through the drivers side wheel well and pull on the transmission. Comes right out and the eyelet supports the trans evenly-ish so it doesn't tip any crazy directions. Don't forget to drain the trans fluid before you pull the trans out.

Putting it back on is much tougher. Took us probably 20 minutes of wrestling and 3 "tries" to get it back on. Same setup as before with the 2x4 and rope. Put the trans on a jack so you can roll it under the car and lift it up so that when you tie the rope it's as short as possible. Otherwise your helper is going to have to hold the end of the 2x4 way over their head. Then remove the jack and let the trans hang from the rope/2x4. Have your helper lift the 2x4 up and you crawl under the car. Lay perpendicular to the car with your feet out the driver side wheel well. Grab the trans with both hands and guide it on. There are two "pins" that it will eventually slide onto. When it seemed like it wouldn't go on I would reach in and rotate the trans input shaft a little bit to try and get the splines to line up. Don't try this after you're super beat because that trans is heavy and muscling it around took a lot of effort. It's easy to hold the trans up with the 2x4 so communicate with your helper and get them to do the heavy lifting (up/down/front/back). Maybe if you actually work out bench pressing 90lbs for 6-7 minutes wouldn't be too bad but I'm a weakling

A cherry picker would be for sure waaaaay easier but I didn't have one so sometimes you just have to make do :D

 

Your wife is a garage superstar! My wife is only 5 foot tall and isn't exactly patient with stuff like this.

Looks like I might be borrowing the picker from dad for the winter.

 

Just thought I'd update this with some pictures I found in a build thread. Looks like I'm not the only one who had problems with reverse coming out when the case was separated...

https://www.northamericanmotoring.co...21-post91.html

 

Yes I remember this post. I'll take note to keep it upright when splitting the case.