Wilwood to LS7 clutch Help

Well, I installed the LS7 SAC clutch pressure plate and D951004 slave cylinder. I bought and installed a new stock 944 clutch master cylinder. After bleeding the clutch system, I determined that the stock clutch master wasnt pushing enough volume preventing the clutch from disengaging. So, I bought the 13/16 wilwood clutch master and Robs clevis. Installed it all, bled it and.....SAME. Still wont disengage!

Im now thinking about pulling the engine and either or both 1) adjusting the SAC pressure plate 2) installing a shim.

Has anyone had to install a shim with the their setup???

Is it a volume issue or a stroke issue? Have you tried adjusting the clevis so it is preloading the master a bit? I know I ended up doing this and the engagement is still a bit high on my 7/8s master and I might look into preloading it a bit more. Do you also have the clutch spring setup in there? If so, try removing that completely.

robstah wrote:Is it a volume issue or a stroke issue? Have you tried adjusting the clevis so it is preloading the master a bit? I know I ended up doing this and the engagement is still a bit high on my 7/8s master and I might look into preloading it a bit more. Do you also have the clutch spring setup in there? If so, try removing that completely.

I have tried adjusting the pushrod but will try again tomorrow. The "helper" spring is still in there but Im not sure how that would hinder clutch disengagement...Its just there to act as a booster. But I guess I could remove it and see what happens. I really dont want to pull the engine again.

944-LT1 wrote:I have tried adjusting the pushrod but will try again tomorrow. The "helper" spring is still in there but Im not sure how that would hinder clutch disengagement...Its just there to act as a booster. But I guess I could remove it and see what happens. I really dont want to pull the engine again.

Yeah, I am just throwing things out there that might make a difference. It would suck to dig back into the trans and motor.

What is the LS7 clutch pressure plate tine throw distance for full disengagement? It could be different than LS1 PP. Also I hope you mounting the MC on it's side didn't restrict the volume available at max clevis adjustment, JAT.

xschop wrote:What is the LS7 clutch pressure plate tine throw distance for full disengagement? It could be different than LS1 PP. Also I hope you mounting the MC on it's side didn't restrict the volume available at max clevis adjustment, JAT.

You don't think it has something to do with the different dimensions of the bellhousing, do you? Remember me posting a C6 bellhousing that was an inch longer?

Mike did you stick on the C6 1-piece bellhousing? As robstah said it is taller than the C5 BH (5.80")

I wonder if something changed in the clutch or pilot bearing with the C6 bellhousing?

This tells an interesting story.....

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The bellhousing is from a 2004 vette. It is 2-piece. I mounted the new MC with the bolts vertical.
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Id have to remove the PP to see about the spring finger travel. Think its documented somewhere?

I havent been able to adjust the pushrod today as of yet. Later tonight I hope to do that and maybe a bit more bleeding because its sooo fun!

I just checked my tech drawing of the Wilwood clutch clevis and there is 1.69" of threading depth...FYI
You didn't make it clear if you added a thicker adapter.

I am using a c5 2 piece bellhousing, with a LS7 PP and flywheel, with a RAM upgraded Dodge disk, 13/16 Wilwood short throw master (mounted sideways) and stock used slave. I pressure bled the system once and have a really good pedal, with clutch engagement at about 1/2 travel of the pedal. I am using the factory clevis assembly with the slave mounted to the inside of the firewall (body of slave cyl sticks through firewall). My money is you still have air in the system.

Mark

xschop wrote:I just checked my tech drawing of the Wilwood clutch clevis and there is 1.69" of threading depth...FYI
You didn't make it clear if you added a thicker adapter.

Im not sure what adapter you mean. The bellhousing adapter is the one you made. Im not using any adapter on the CMC. I know (I think ) I have enough clevis threads to work with.


Mark, I will try bleeding again...actually, im going to flush the fluid. For some reason, it turned black!!

I adjusted the clevis all over the place and bled it (bottles worth). Still no go.

Rob, the clevis is perfect. I cant find anything wrong with it. I set the clevis so that theres no slack in the pushrod to piston and pedal.

Ive read that these systems should be power bled but I cant bring myself to buy another something with the chance of it not fixing the problem.

Im thinking the SAC adjustment is off = Im gonna have to pull the engine.....again.

O.k. I thought you sent a pic of the 90 degree adapter, so that's not the issue either. If you have a long SS line as a "remote bleeder" it may actually be harder to bleed unless you put a vacuum on that end. I only had the small stub bleeder on mine and it was easy to bleed.

And the black is just the grease that the factory puts on the polished inner seal surface for the bearing wiper....keep trying

xschop wrote:....keep trying

Bleeding?!?!

Don't laugh, but on my bike when I would flush the lines, I would fill the reservoir with fluid and crack both left and right calipers and blow in the reservoir, it would fill all the lines in about 10 seconds because the prime port was large. I'm not sure how the wilwood is, but it may work.

Ive got an extra cap. Maybe I will drill it and install a nipple for the compressor. Worth a shot I guess.

If it works and I get more air out, the tick performance remote bleeder is a worthless piece of sh**. Ive read that some have had problems with it leaking.

Ive ordered two shims from Tick, 0.180 and 0.113 and resounded myself to pulling the engine. While I wait for them to be delivered, I will force bleed the system.

If it doesnt work, I will, after pulling the engine, bench bleed the entire clutch setup. Im thinking, slave high up clamped to the top of a ladder and the clutch master low???

Rob.....Id rather've bought them shims from you hint hint! You probably couldve made them from aluminum fer me.

Update...

I got the shims in, pulled the engine, and did the measurements.... No shim needed. That wasnt even the problem.

Once I got the engine out and the pressure plate off, I found a scorched pilot bearing.

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This is the thicker 35x15x14 mm bearing PN# 62202 2RS by FAG. The outer race was in contact with the clutch disc hub which caused the blue coloring and scrapes. I removed this bearing from my pilot bearing adapter and installed the slimmer 35x15x11 mm version PN# 6202 RSR by FAG. This cured the problem.

So, after buying a new OEM clutch master, a wilwood 13/16 clutch master and required fittings and the tick performance shims, it ended up being a few millimeters of pilot bearing.

As mentioned before, I measured for the shims... the measurement from PP fingers to adapter plate face "A" is 2.25" and the measurement from the TOB surface to adapter plate face "B" is 2.125" which gives 0.125 inches. According to all those threads on LS1tech, it requires no shim.

What a PITA but glad I found the problem before spending mo money!

Mike, what clutch disc are you running?

LuK LS7 flywheel/PP and a LuK clutch disc. Ive been thinking of looking at different clutch discs to see if I can find a disc that doesnt interfere with the 14mm bearing.

I was about to ask if your flywheel was new or re-surfaced. Also if you look at pic#4, first page of my build thread, you can see that the 14mm bearing is exactly at the Flywheel plane. Whatever clutch disc you use, the splined hub backside has to set away from the FW face by the same thickness as the rear clutch disc facing because as the disc wears the rear splined hub will migrate towards the pilot bearing.

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The flywheel and PP are as stock new. I think the LuK clutch discs just have an extended hub on the flywheelside of the disc that protrudes further than others.

Im going to mock it all up without the clutch parts to check depth of TT tip into the 11mm bearing. If no good, I will get another disc with a less pronounced hub on the flywheel side.

To close down this thread...

All is well! I adjusted the ls7 SAC adjustment on the pressure plate to stock setting, installed the clutch components to the engine, out of the car on the hoist, and as well the BH and slave/adapter plate assembly. I didnt want to install the engine and everything into the car just to take it all back out if something was amiss. Good thing I had the 26" slave hose; with the engine on the hoist, I pressed the clutch pedal and could hear the SAC adjustment....readjust, and the clutch disc turned freely when turning the clutch disc alignment tool. As far as the bearing goes, I checked driveshaft insertion with the 11mm bearing and it checked out quite fine.

Installed the engine, primed the fuel, started it and.... well.... not thinking of it at the time, I wasnt sure how the new master and LS7 clutch would behave....the tires squealed and I burst into the inside of our closed garage door....in reverse.... Yup, that just happened.

Regardless, the clutch action is super precise and smooth. Im happy with the frivolous purchasing of the wilwood 13/16 and the rest of the clutch system (even knowing now that none of it was needed), other than what it did to the poor garage door.

So, for all of you harboring thoughts of installing an LS7 clutch, learn from me, save some money (and your mind....and maybe a door), check the distance between the clutch disc and bearing before final install of your engine!

Sounds like a great job on the clutch. And we need pics of the garage door! :-)