Too heavy a clutch. could this be causing my engine problems?

[Al Weyman]

Funny enough I was thinking of your clutch finger post when I was playing around with the clutch this afternoon as the release bearing had some wear grooves in it, not bad but evindent.

Right oddly enough I have the McCloued instructions right in front of me and they say 125 to 150 thou clearance between clutch and bearing with the bearing forced right back. It will obviously come out the first time you depress the clutch in much the same way as a brake pad will but also like a brake pad I would assume the rotating clutch fingers would knock the bearing back a few thou so not always in contact. Reading it more throughly it actually says min 100 thou max 300 thou clearance and the 125 to 150 being the optimum.

[Tim Falce]

**** it I think I may have to take the engine out again, this'll be the third time in as many days.
Just checked the QuarteMaster website and it says .100 to .160 inch which is 2.5 to around 4mm, the latter seems excessive as I only have 12mm of movement in the slave cylinder.

[greenamex2]

Having had a concentric slave cylinder pop out at Pembrey last year, it's really not something you want to fix in a wet muddy cold paddock.

Thank god for universal O ring kits and the well equipped Wirral boys!

[Al Weyman]

How much clearance do you have Tim? See this is what bugs me somewhat, the units I am using, hydraulic release bearing and clutch are from the smae manufacturer used on a Muncie gearbox which must be very common and yet I have had to cut down the standard snout retaining bolts where as logic would tell you its a straight bolt in job, obviously not!

I think the reason you have to have the extra clearance is as a margin for when the driven plates wear down and the diafram fingers will then get closer to the bearing, not enough clearance and she will hold open and start slipping in no time. Its probably fine with not enough clearance as long as you periodically check it for wear. Can you adjust the preload on the clutch unit, becasue maybe you do not have it tight enough and need to remove some shims as you should do as the driven plates wear down. On my clutch the fingers have to end up flush to the diaframe retaining alloy plate if that makes sense.

[Tim Falce]

I thought I'd posted the answer Al but here goes again.
I've taken the engine out again and it seems I got my sums wrong and only had .006" clearance which may account for my broken crank last year. I've looked on the QuarterMaster website again and it seems it needs .160" clearance so quite a difference. There are no detailed drawings of the clutch but the AP site says a max movement of 5mm for their tripple plate clutch so going off that I should have plenty of spare travel on my slave cylinder.