Technical Clutches: Long vs. Diaphram

Having delt with a long (3 lever) clutch pressure plate and really heavy pedal pressure. While the transmission is out, I've been reading that a diaphram type pressure plate would yeald a noticeably lighter pedal effort.

This is for street use, and 300 ft/lbs of torque.

Any thoughts? I may call modern driveline tomorrow and see what kind of replacement they carry to replace what I have.

 

What motor?

 

Diaphragms are definitely a better pressure plate choice because of lower efforts and cost. Most diaphragms require an evenly spaced bolt pattern, but there are some that directly replace the Long. Just match the finger height, and T/O bearing size for either straight or bent finger plate design.

 

Bob, have you figured it out for 59 ab's with stock ford trans?

 

Centerforce Dual-friction is what you want.... Much less pedal effort. Welcome to Centerforce Performance Clutch

 

Posted this about a week ago, but here it is again.



Contact Ky Clutch and they will ship you a nice clutch that will be a lot cheaper than you'll find elesewhere. They are rebuilders but also build competition clutches. A simple rebuilt should be fine for your needs. Call about noon EST and ask for Dave. Old hot rodder who owned the business till he retired and he just goes over there every day at lunch time to help out. Good People !

 

Like Steve stated, Centerforce offers straight and bent finger plates for early and late Ford input/T/O bearings, but a good clutch re-builder should be able to match your finger height, bolt pattern, T/O and hp/torque requirements, like our local South Bend Clutch.

 

This is for my '59 Galaxie 352. Putting in an overdrive toploader from a 79 Mustang.

I have the later bell housing with the push type starter.

I can drill and tap new holes when I have the flywheel out.

I was ready to reengineer the clutch linkage the pedal was just really heavy.

 

I was really pleased with the dual-friction. They use a fairly aggressive compound on one side for power handling and to reduce pedal effort and a harder one on the other for smooth operation. It's going to cost more than a stock replacement but they're very competitive price-wise with any of the other 'names'...

Don't forget to check the pilot shaft length before installing the trans.

 

Just curious with the aggressive compound on the flywheel side, is wear a concern on the FW?
I’ve not much history with manuals the past 30+ years.

 

It's actually a somewhat soft 'sticky' compound, so flywheel wear isn't an issue. I had the trans out at about 25K miles and took a look, everything looked fine. Clutch wear didn't seem to be any quicker than normal, but this was street use.

 

I used the Centerforce dual friction in my 32. I was very satisfied with it's performance.

 

I'll get it all removed this week so I will have the part number off the existing unit and have measurements.

Being able to remove a transmission and leave the bell housing is soooooooo foreign to me!

 

One thing you want to check is that the hole in the bell housing is a good fit for the front bearing retainer on the transmission. Sometimes the hole is too large. The transmission slips in just fine, but it would not be in alignment. Chevy's had that problem, don't know about Ford's.

 

Dial indicator to check center . Borg and Beck is the best design I have ever used . Long style have always seemed to chatter easily , diaphragm is not in my repair book to use .

 

I swapped out my long style pressure plate and used a centerforce 2 diaphragm type. Clutch operation is much easier and smoother and I can drop the clutch at five grand and the thing don't slip!in my avatar 29

 

Before you spend any money, have you tried to reposition the push rod on your clutch pedal? Perhaps moving it an inch might solve your problem.

 

I'm going to replace the clutch and resurface the flywheel. The old long clutch definatly had a chatter.

 

I remember shredding that trans in a stock '79 5.0l. I hope you have better luck with it behind an FE.

 

What broke in it? I've got 2 of these OD transmissions apart and a '69 3 speed toploader close ratio apart as well.

Honestly I dont see much difference, the OD had bigger bearings and heavier main shaft. The gears for the 4th (overdrive) are definatly narrower. 1 gear is the exact same as a traditional toploader.

I can definitely see where overdrive puts load on the cluster gear all the time where as a 3 or 4 speed would be direct drive in top gear and put no load on the cluster gear.

I'm not at all being a smart ass, I'm honestly curious. I dont have any other experience with these until I got this car.

 

Some comparisons