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Mystery! Loyale Clutch Pressure Plate Specifications?


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A week ago I posted this question, as my new (self-installed) clutch was slipping a lot (read: going max 4mph on flat ground in first gear, and giving off clutch smoke), and I thought I'd burned it up, and one thought people had was that I'd overtightened the hill holder, causing the clutch to slip, and then tried driving up a hill:

 

Short version: Is it plausible that I fried my new clutch on a 91 Loyale by not tightening the hill holder/clutch return cable sufficiently after installation? If so, why did it fry out only after I adjusted it "properly" according to Hayes, and not right away? OR, is something else wrong with this sucker that I'm not thinking of, and will it just fry out the next disk I put in there?

 

... but when I got in there yesterday, THE CLUTCH WAS FINE! :confused: Ooops. The clutch showed just (barely) a smidgin of wear, no oil on it, and the machining marks on the pressure plate and flywheel were fine, and no sign of overheating or anything. There's no reason to suspect the transmission (I hope) as the fluid level was right, and it worked fine before I replaced the clutch. I took the clutch, pressure plate, and flywheel to Baxter Auto Parts' machine shop, and the guy measured the specs: 820,000ths for the step on the fly wheel, and he measured up the pressure plate and the clutch, and said there was an extra 100,000ths (i.e., thickness of pressure plate plus clutch equals 920,000ths).

 

My questions are: does anyone know if 100,000ths of extra thickness in clutch and pp (over the depth of the flywheel step) are enough to create enough pressure to keep the clutch from slipping?

 

Also, Baxter's machinist said that the book calls for 900,000ths of step in the flywheel, but the step on my flywheel was only 820,000ths - however, if anything, this would have kept the clutch from slipping, not caused it to slip.

 

Does anyone have any ideas? I double-checked that Baxters gave me the right parts according to their computer system, all the thicknesses of the new pp and clutch match up to the old pp and clutch and throwout bearing. As far as I can tell, the tranny, flywheel, engine (EA82) housings, etc. are original.

 

Thanks for your collective brain power!

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Is your car a 2WD or 4X4, did you put in the right clutch? 80 thou on a flywheel is not out of line. I doubt that a 4X4 plate could be with a 2WD pressure plate unless the unit is for an '83 or '84.

It sounds more as if you had the clutch cable too tight, not allowing the pressure plate to squeeze the clutch plate. Loosen the clutch cable right off, so that you can feel looseness on the release lever with your fingers. Try to drive like that. As long as the clutch is not slipping, tighten the clutch cable adjustment until the pedal height is up to the lowest you are comfortable with, bearing in mind that pedal height increases as a clutch wears. When you are happy with the pedal height, tighten the hill-holder adjustment until you can slip a dime between the coils of the spring, a little less if you live in a hilly area.

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Is your car a 2WD or 4X4, did you put in the right clutch? 80 thou on a flywheel is not out of line. I doubt that a 4X4 plate could be with a 2WD pressure plate unless the unit is for an '83 or '84.

It sounds more as if you had the clutch cable too tight, not allowing the pressure plate to squeeze the clutch plate. Loosen the clutch cable right off, so that you can feel looseness on the release lever with your fingers. Try to drive like that. As long as the clutch is not slipping, tighten the clutch cable adjustment until the pedal height is up to the lowest you are comfortable with, bearing in mind that pedal height increases as a clutch wears. When you are happy with the pedal height, tighten the hill-holder adjustment until you can slip a dime between the coils of the spring, a little less if you live in a hilly area.

 

Thanks! - good to know on the 80,000ths and the hill holder adjustment - Car's a 4x4, double checked with Baxter's and the clutch is a 4x4 clutch too. I re-double checked the free play and all on the clutch cable before taking out the clutch and it was fine - 10mm freeplay and then tried it again looser - and the clutch was still slipping.

 

Hunch is that I didn't get the pressure plate on there completely tight when I installed it (one of the alignment pegs is a hair crooked), but I want to eliminate all else first.

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I had kind of the same problem after I put a d/r 5sd turbo tranny in my 86 brat. because the transmission was from a turbo the disk had to be from a turbo so I bought the turbo clutch kit and installed it. When I got around to driving it it would not fully engage, long story short I had to take it out and when I compared the pressure plates the new one from the turbo didn't go as deep as the old one thats why it didn't engage so if you still have the old pressure plate compare how much they travel, you could probably use the old one just rough it up with some sand paper and go to town:burnout:

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did you tighten the pressure plate in the correct way...i.e. like a tire? you dont just go in a circle and tighten as you go. aside from that i cant think of anything unless your clutch cable is horribly worn and stretches that much. dont re-use pressure plates or clutch discs, you can get away with it for a little bit, but not a good idea, unles you dont have the funds to buy new stuff.

 

~Josh~

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did you tighten the pressure plate in the correct way...i.e. like a tire? you dont just go in a circle and tighten as you go. aside from that i cant think of anything unless your clutch cable is horribly worn and stretches that much. dont re-use pressure plates or clutch discs, you can get away with it for a little bit, but not a good idea, unles you dont have the funds to buy new stuff.

 

~Josh~

 

Why do you have to tighten in a star pattern? I have never heard that before. Never done it either, and I've changed a hell of a lot of Subaru clutches. I mean - it's not as if there is a gasket in there, and neither of the parts are aluminium. BTW - cool trick - leave all the PP bolts really loose so the disc can move around in there. No alignment tool needed, just slide the engine on, and tighten the PP bolts through the starter hole.

 

As for re-use, if it was working before..... should still work.... the same does NOT go for the bearings however. Change them as they are cheap and will cause you a headache if you don't. Generally yes, you should just change everything, but in reality, a subaru is not a swiss watch, and we Subaru owners are not the richest in the land. Turn the flywheel? I usually don't. Replace the PP? Unless it's really bad, not me. I generally get a not-to-worn disc from the junk yard, and new bearings. For my off-roader anyway. For my daily I might actually buy a NEW disc. They are reasonably easy to change if you have access to a cherry picker, and usually give ample warning before anything dies completely (bearings can be the naughty exception).

 

GD

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