Quick Synopsis: '03 MCS 67K miles, After Gruling 3 hour traffic battle in NYC, my clutch pedal felt weird; grabbing at different heights, I barely made it home, the next morning the pedal dropped to the floor and stayed there. I replaced the Slave Cylinder (no leaks) but then had slip and shudder. The T-O bearing never made noise.

Upon disassembly, I found the friction disk shredded, but to my surprise found the Throw-out bearing shaft bushings melted to the shaft , I cannot move the shaft by hand and only after some penetrating oil and a breaker bar can get it to move. Did these $.60 and $1.75 bushings melt on the shaft preventing the clutch from fully releasing,and cause the clutch to overheat? It would explain a lot (over 700K miles experience on manual transmissions). or did the heat from the clutch melt the bushings? I know what Mini would say.

 

Wow, that's truly melted! Ouch.

I had a clutch go bad a few years ago, and the bushings sagged a bit from the heat (in that case I KNOW that the clutch went bad first). I thought my bushings were bad, but they actually still work well and do not grab the shaft. Yours are just amazing.

 

inner bushing, although a little toast was free, the outer bushing was seized up, I think not from heat but corrosion, the shaft is Cold Rolled Steel, and the actuating arm is cast iron and held in place with a roll pin, the galvanic corrosion had pitted the shaft under the bushing causing it not to fully release the clutch once depressed, quickly burning the clutch. I highly recommend frequent lubrication in this area.

I did the clutch in my garage, although quite daunting and total work time exceeding 20hrs...I'd do it again if I had to.

20hrs includes replacing both drive shafts (right one had torn boot) by the way the carrier on the mid shaft must be pressed off, crank sensor o-ring, rear main seal, trans input shaft seal and sleeve, both shift rod bushings, supercharger to inlet duct gasket. (hint- the little red connectors on the inlet duct-push down on the red plastic and pull up on the hose). I also snapped a bolt replacing the subframe, the right control arm bracket, by the way the Bentley book says to replace these bolts and the torque is only 44 lbs versus the other subframe bots of 74 lbs.

The clutch bleeding was frustrating, finally after using Bentleys approach I took the slave cylinder and put hose on bleed screw into jar and cycled the slave cylinder with my hand, all the bubbles came out (be sure to keep reservoir full. I installed a Valeo oem replacement (single mass FW) and sprung clutch, only 50 miles on it so far, but feels OK...

 

I don’t see how galvanic corrosion could be to blame because the nylon bushing isolates the shaft from the aluminum boss.

44 ft-lb plus a torque angle of 90 degrees is the spec for the bracket to body TTY bolts.

So, by OEM replacement you mean a Cooper clutch in an MCS transmission?

 

Sad to see your clutch burn out on you SeanKidd.

I think Valeo has Cooper S flywheels now in stock to go with their clutch kits K-huevo.

Jeremy

 

The Valeo Kit is for the MCS, single mass flywheel (heavy) sprung hub clutch, TO Bearing and grease...the galvanic corrosion is between the CRS shaft and the cast iron arm, the arm was heavily exfoliated.
I made an alignment tool with the plastic clutch centering tool slid through a 1" axle nut (happened to have the same diameter of the PP fingers)

 

That's not a bearing surface; it may look bad but it won't impact movement.

I like words, I've read the word "exfoliate" in skin, bone, tree, and rock contexts, but never iron.

 

All I know it took a wrench and lots of PB Blaster to work the shaft free from the bell housing and bushing. I wire wheeled the assembly and the area where the bushing rides was pitted. Time will tell, but I'm putting that on the list of things to hit with dry lubricant.