Clutch issues again!

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ozmoparjoe

ozmoparjoe

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Hey all, as the title says im having clutch issues again, so basically i fried my original clutch so i had the local clutch company here (Exedy) make me a new clutch plate and pressure plate, tried to get it to work but just wouldn't play ball, clutch wouldn't engage properly so couldn't select gears, removed the pressure plate and gave it back to them for testing and they told me it was faulty, so they gave me a new kit, installed it tonight, went to test it and same thing!
It's just not engaging the clutch, it moves a little but not enough. It has a Powertrain Technologies Street Max hydraulic throwout bearing thats working fine.
Pedal feels good, good travel, all air out, throwout bearing travelling its full 3/4" length, gap between bearing and pressure plate fingers is approx 0.150.
when i tightened down the pressure plate, the diaphragm fingers were straight, i believe this is correct, clutch plate is on the correct way.
If anyone can shed some light on this i'd really appreciate it as i love the 4 speed and really dont want to convert to auto!

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So you are getting a full 3/4 inch travel when installed? I have a Centerforce clutch and the manufacturer states only 1/2 inch travel is necessary. Maybe there is just enough air in the system that when placed under load, the travel isn't as far as when bench testing it?
 
I've never run a hydraulic throw-out bearing, so I don't have the experience needed to advise, but I will say the .150" gap seems a bit large. Seems to me I was told to set up my manual throw-out bearing to have a .060 - .090" gap when pedal is up. Have you tried reducing that gap?

The other thing that concerns me is you saying the diaphragm fingers being flat when the pressure plate is tightened down. I don't have a lot of experience with 4 speeds, but if memory serves, every pressure plate I have seen tightened down still had the fingers pointing slightly outward so there is room for them to move before they reach end of travel.

I wish I had a picture of mine from a different angle, but I swear the fingers on my McLeod pressure plate were still pointing outward once it was tightened down. The only pics I have at the moment is looking straight at it (see attached)

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The hydraulic throw out bearings that I have used the gap is around .100. Just my thoughts, Good Luck
 
if you are saying the fingers are flat with the plate bolted down that's wrong they should be raised slightly that could be caused by too thick of disc or the plate assembled wrong also your release bearing could be leaking through at a certain pressure acting like a pressure relief valve and last how tight does your input fit ? does it fit loose ,so it wont be glued to the crank and almost last is your crank a manual crank or has it been drilled so the input wont bind into the crank?
 
Is there any possibility it could be an issue with the master cylinder or hydraulic throw out bearing? If either was preventing you from getting full travel, it would explain why you fried the clutch in the first place and why you're still having issues
 
ozmoparjoe said:
Hey all, as the title says im having clutch issues again, so basically i fried my original clutch so i had the local clutch company here (Exedy) make me a new clutch plate and pressure plate, tried to get it to work but just wouldn't play ball, clutch wouldn't engage properly so couldn't select gears, removed the pressure plate and gave it back to them for testing and they told me it was faulty, so they gave me a new kit, installed it tonight, went to test it and same thing!
It's just not engaging the clutch, it moves a little but not enough. It has a Powertrain Technologies Street Max hydraulic throwout bearing thats working fine.
Pedal feels good, good travel, all air out, throwout bearing travelling its full 3/4" length, gap between bearing and pressure plate fingers is approx 0.150.
when i tightened down the pressure plate, the diaphragm fingers were straight, i believe this is correct, clutch plate is on the correct way.
If anyone can shed some light on this i'd really appreciate it as i love the 4 speed and really dont want to convert to auto!

View attachment 1715254127

View attachment 1715254128

View attachment 1715254129

View attachment 1715254130
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Pedal up/pedal down doesn't look much different. Yes there should be an air gap between the t/o bearing and the pressure plate fingers with the pedal up and a gap between the disc and the pressure plate and/or flywheel with the pedal down. With manual linkage the progression is more gradual. With the hydraulic I don't know. You should get release somewhere in the middle of the pedal travel I would guess.
 
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I had a similar problem once with a 3 ton Ford truck. The problem was the supplied friction disc was almost 0.125" too thick. Swapped in a thinner friction disc, and all was well.
 
I'm confused with your statement on 2nd line, clutch won't engage to select gears. Clutch has to disengage to select gears. With the pedal up, can you turn clutch disc? If so pressure plate isn't doing it's job. Pressure plate clamps disc to flywheel when released. I have mechanical linkage on a 5 speed and never had a problem.
 
Thanks for all the replies guys, i eplained about the flat fingers to the clutch guy, and he seems to think that the clutch disc may be too thick as a couple of you have stated here, so tonight after work im going to put a washer between each pressure plate bolt and flywheel to space it out just for testing purposes and see what happens, ill keep you all posted, thanks again!
 
ozmoparjoe said:
Thanks for all the replies guys, i eplained about the flat fingers to the clutch guy, and he seems to think that the clutch disc may be too thick as a couple of you have stated here, so tonight after work im going to put a washer between each pressure plate bolt and flywheel to space it out just for testing purposes and see what happens, ill keep you all posted, thanks again!
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Good diagnostic trick!
 
ozmoparjoe said:
Putting machined washers between the pressure plate and flywheel and driving the car like this, is this a bad idea?
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My American Powertrain hydraulic release bearing is designed to move 1/2 inch. Are you able to verify that yours is moving a full 3/4 inch when depressed?

I understand your frustration, as I've had my transmission in and out about 5 times between swapping in, out and in a five speed and then discovering I also had clutch and release linkage issues. It's currently coming back out to have the pressure plate rebuilt at McLeod again. (oil contamination the last 2 times.)

It sounds like you have incorrect parts in the pressure plate/ clutch disc components. I don't think its a good idea to run the car with the washers, because the thickness required is not a known dimension. If too thick, they could cause slippage under load.
 
jbc426 said:
My American Powertrain hydraulic release bearing is designed to move 1/2 inch. Are you able to verify that yours is moving a full 3/4 inch when depressed?

I understand your frustration, as I've had my transmission in and out about 5 times between swapping in, out and in a five speed and then discovering I also had clutch and release linkage issues. It's currently coming back out to have the pressure plate rebuilt at McLeod again. (oil contamination the last 2 times.)

It sounds like you have incorrect parts in the pressure plate/ clutch disc components. I don't think its a good idea to run the car with the washers, because the thickness required is not a known dimension. If too thick, they could cause slippage under load.
Click to expand...

Thanks again for the replies guys, so i have installed some washers between the flywheel and pressure plate (from memory they are 1.5mm), and this seems to have made it driveable, although the clutch would release as soon as i lift the pedal off the floor, i then made a bit more of an adjustment with the pedal rod under the dash, and that helped a bit more, so now i will purchase some proper shims, as i only used normal washers to test. So yes at this stage its driving well and pedal release feels ok, jbc426 i believe you are right about incorrect parts, i repeatedly told the shop that the pp diaphragm "fingers" weren't angled out enough so there wasn't enough movement, plus the clutch disc being a little thicker didn't help the situation!
Thanks again guys.
 
My son's Infiniti G35 slave cylinder had the bleeder on the bottom, you have to remove the slave cylinder and rotate the bleeder to the top to bleed the system and then reinstall. Craziest setup I have ever seen. Rod
 
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