[rugger]

I have just put my 350 hp/2500 lb car on the road. I've worked out most of the kinks, but the clutch has not worked correctly. I'm running a Howe hydraulic throwout. The throwout seems to be working correctly. As I recall, I installed it correctly, with the proper spacing from the clutch fingers. The clutch starts slipping around 3000 rpm......2200 rpm on hills. I've been very easy on the clutch due to the CF requirements for break-in. I'm pretty sure that I'll be pulling the engine and tranny to see what's going on. I'm thinking that the clutch plate must not be properly engaging the flywheel. What do you guys think?

edit: It's a 327 mated to a M21 with 3.27 gears

 

[Hi-po SS 454]

Must have New or resurfaced flywheel? Wrong clutch fork? Wrong length ball stud at bellhousing? At least 1 inch play in pedal for a decent clutch adjustment. Doubt if anything is wrong with the clutch itself. But with slipping it will mess the disc up.
.

 

[rugger]

New flywheel, no clutch fork, no ball stud, clutch adjustment is done at the hyd throwout with shims - .10 spacing between throwout and and clutch fingers

I have about 130 miles on the car since the engine/tranny/clutch etc were assembled. It took off well out of the drive this morning, but by the time I was 100 yds away it had started slipping again.

 

[68KMENO]

on the flywheel to crank bolts .... where they the correct ones ?? THIN heads ??

I've seen disc's hit these bolts grinding off enough metal to screw up a new clutch install

 

[Mike]

Disk in backwards ?

 

[rugger]

on the flywheel to crank bolts .... where they the correct ones ?? THIN heads ??

I've seen disc's hit these bolts grinding off enough metal to screw up a new clutch install

They are stock bolts with a stock flywheel.

Disk in backwards ?

Mike, I hope that I'm smart enough to put it in correctly....but I may have screwed it up. It sounds like you all are thinking the same things that I am. The bottom line is that I'm going to have to pull it.........bummer.

 

[Bow_Tied]

Let us know what you find, good luck.

 

[jthomp1256]

take off inspection cover where slave cylinder is and have some press cluth to see if it releases properly ,or some how bleeding back and letting off pressure just a thought Jeff

 

[rugger]

For the love of God, I don't have a slave cylinder. It is a hydraulic throwout bearing........no clutch fork, no ball pin, no slave cylinder, etc.

However, I do need to check and make sure that my master is not preloaded by the pedal......I don't recall if it has any adjustment to it or not.

 

[z15cam]

I don't believe you have a hydraulic slave problem either as you don't have one. I used hydraulic slaves on Volvos for years and they are about fool proof - lol. OK here goes my attempt It's possible that the bell housing is not centering the transmission to the pilot bearing or the pilot bearing is shot causing the tranny input shaft to wobble. If you note the center spline on the clutch disc is loose or the play of the tranny input shaft seems excessive would indicate either of the above in which case you would have to replace the front tranny bearing as well of taking care of the cause. This situation usually causes one hell of a vibration before the clutch actually slips. Another thing is that the cylinder on which your Howe Hydraulic throwout bearing slides may be worn causing the throw out bearing to vibrate against the clutch diaphragm. I had to weld and lathe the nose of my M21 true once.

 

[rugger]

I have good news.

I went out to the garage to check the clutch pedal and clutch master rod engagement. Let's say that the clutch pedal moves about 30 deg about its axis of rotation. I was seeing about 3-4 deg of preload or 1/8" at the rod. It is a bear to adjust and reinstall the rod, so I took the rubber bumper that the pedal seats against and shaved it 1/8". I went to sleep, and drove the car into work this morning with no slipping. Holy crap I am relieved. Kudos to Centerforce for making a clutch that will take the abuse of slipping for a week and still hook up when the installation is finally proper.

Next order of business is to figure out which jets I need for my Edelbrock......she's running a bit rich.

Thanks everyone.:beers:

 

[Bow_Tied]

Is it the slave cylinder?

Glad you got it figured, thanks for posting the solution.

 

[69-CHVL]

Just another testament to the quality of the DF cltuch.

I have about 2 dozen passes on it. 2nd gear waterbox burnouts, and good launches at the strip with the ET streets. NEVER even made a smell, let alone slipped.

And - mine also slipped about 1/2 dozen times b/c I didnt have enough freeplay. And its still holding great, and absolutely no chatter! How can you go wrong for 300.00?

 

[z15cam]

So you're saying that the pedal is now approx 1/8" higher up off the floor. I'm surprised that there is no other adjustment on the Slave or Howe Hydraulic throw out unit to position the clutch release bearing.

Anyway, I'm glad you got it working and the clutch is not damaged.

 

[DougA]

I installed a new CF Dual friction 4 years ago,and after my second time at the dragstrip this spring it was slipping on a hard launch.Called their tech department and they said that shouldn't be happening with my pretty much stock setup.They told me to remove it and send it to them and if something looked amiss they would replace it.Called em after 2weeks and they said my clamping pressure was off by about 800 lbs. and a new complete setup was on the way free of charge.Pretty damn good customer service after 4 years of use I'd say.They could have blown me off just as easy.They now have a customer for life and I like to help them by telling people my experience.Very little of this kind of service in this day and age.:thumbsup:

 

[rugger]

So you're saying that the pedal is now approx 1/8" higher up off the floor. I'm surprised that there is no other adjustment on the Slave or Howe Hydraulic throw out unit to position the clutch release bearing.

Anyway, I'm glad you got it working and the clutch is not damaged.

Nope, the pedal attaches to the linkage which engages the master cylinder piston. The linkage was positioning the piston with about 1/8" preload. The Howe throwout is adjustable by using shims. I was not wanting to pull the engine and tranny unless absolutely necessary.

The clutch never smelled while slipping.....truly amazing. It is fine now, and I am amazed and surprised at that. She's running like a scalded dog.