When I took the drive train out for winter inspection (only 800 miles on her), I noticed by 11" Mcleod disk was coming apart by the rivet holes on the flywheel side, small pieces, but was gouging up my new flywheel, and I have only had BFG TA radial street tires on her so far. It is obvious the clutch is not holding the power although it felt fine and I couldn't notice it slipping. Good thing I caught it as she would have disintergrated with the first use of slicks. I could go to a dual disk that I hear holds up to 1200hp, but I think that is more than what I need, as there would be absolutely no slippage and I am concerned about breaking parts for this mostly street car that will see slicks and the strip on a handful of times this year. I have called Mcleod tech every day for 3 weeks straight..5 times a day and I can't get through to anyone. I left messages with the lady in sales, but they don't return my calls, so I am turning to you guys for advice.

Who out there has a manual trans with 550 or better ft lbs of torque and has a clutch that holds fine with slicks. If you fit this description, please let me know what you are using and how it is working out for you. A light pedal feel is important.

thx.

a question

when you installed the transmission did you have to fight it the last .25 to .5 inch? or did you have to pull the trans up to the bellhousing with the trans bolts?

the reason i ask is your pivot ball height could be too tall causing the throwout bearing to engage the clutch slightly, which would explain the trans not wanting to seat all the way without forcing it.

i believe a simple test to see if this is happening is to check for an airgap between the throwout bearing and clutch fingers. get under the car and grab the end of the the clutch fork and wiggle it, there should be some movement and you will be able to hear the bearing clack against the clutch fingers. if it doesnt, you found your problem.

the reason i mention this is because i had this exact same problem, except i bought a new centerforce before i figured it out.

I'm using a custom built McLeod Street Twin Dual disc behind my 540.....675 ft lbs. It WILL hold the hp and has low pedal effort. I had used a Centerforce dual friction for a long time with good results, but it was on the edge when I broke 700 hp, and slipped noticeably when I got over 800 hp.

You have to decide what you want to do with it. *IF* you want one to slip a little on the launch, it takes a very aggressive lining material that will handle the heat and also be able to recover from the slipping and then hold once you get moving. Now you're talking sintered iron and BIG $$$. Plus there are the quirks of using one. I've been studying a lot on the issue and talked to all the major mfgs. You have to be very commited to use a slipper style to make it work right. It will have low effort, but is much more likely to chatter etc. There is the whole adjustment/setup cureve with dialing in static and centifugal assist. Often folks use data loggers to get it right. My car is to the point where I could use one that can really slip to help it get moving smoother. But so far I haven't broken any driveline parts with it (3600 lbs-10.04@141 mph). Works smooth, shifts clean and doesn't chatter.

So, I can tell you that for 99% of stuff out there, the Street Twin is the way to go (but it ain't cheap either!) on the street. It will likely outlive you. I've got friends making almost 1500 RWHP (N20 632) with one and another has had his in place for 10+ years behind his 540.

I'm seriously thinking of moving to the slipper style clutch on my Vette, so if you want a good deal on a Street Twin..drop me a line. You might be able to help me get off the fence and make the jump!


JIM

I'd call Mcleod. Sounds like a warantee issue.
Probably try to get you to buy the twin disc though.
Might try and use their metal puck style disc. Can't recall the series.
They can rebuild your disc one way or another at a discount.
I've done it. If your car is quiet enough, you can hear the metal disc style clutches. Sounds like sandpaper down there.
Kevlar has proven to not hold up in lock up converters so I'd be leary of those for street.
Might not be an issue in a drag car with is low mileage.

Oh and the twin disc is 2 street compound discs unless you go with a race unit.
Plenty of slip.
The metallic disc I have slipped fine when cold. But would chatter once warmed up. Had to pump the pedal or let it all the way out to work around it or just deal with it. Should just be able to let it out with your 1st gear except for pulling in to parking space.

Try the Centerforce dual friction. We just put on in my friends 468" BBC 68 Camaro and like it a lot. Pedal effort is minimal. We keep frying the tires on the car (Hoosier QTPs) and the clutch grabs pretty solid.

I **think** a local friend found the limits of the CF/DF and that's when you hit 550+ lbs/ft early on, like 3000 rpm. He slipped his at low R's. We "reckoned" that unlike my L88 ( which has less lbs ft) which has a high torque peak, his tweaked 502 was "all-in" early on, and the centrifugal action of the clutch wasn't happening at low R's. Anyway, decision time, go with a high dollar $800 setup or a T400 and have no fun.

Short answer, if you really have 550 lbs ft early on, it might not hold. Less than that , or a higher torque peak, and its fine. I've loved the C F/DF.

I bought a RAM setup :
Pressure plate 402
Disc (26 spline), 980
Bearing 488.
It seem to hold up well..

How much torque do you think you have "BB wowbagger"?,

I finally got through after sales put me through to "George", someone who explained that he started the business with "Red" and had a lot of got information.

I was informed that I was sold a stock, "soft" clutch (#260171 11" disk, #360803 pressure plate) that wasn't holding the power. I bought my McLeod cluth from the people who I bought my TKO kit from and I was told then that the clutch was good for 550hp, even says it on my invoice. BS!! This is another thing this vendor got me on. Fortunately, now we have Jeff selling TKO's, but he wasn't established yet back when I bought mine. Stay away from the other vendor (you can probably guess) and buy from Jeff only.

Anyway, George at McLeod said that a McLeod twin disk set up would be overkill at 550 ft lbs of torque. It wouldn't allow for hany slippage at all and be harder on the drive train...and would be expensive, too.

He suggested that I incease the surface area by going to a 12" cheater clutch which will fit on my 168 tooth Hayes flywheel, go to a heavier cone, and use a 800 series disk with Kevlar material which will take the heat better over organic. The part numbers he recommended were a #260873 disk (26 spline for TKO) and #360820 diaphram pressure plate. He said this should still have the pedal feel of a stock 69 Camaro for the street.

He also has a strong suggestion for how to save a clutch for stick cars with slicks, which contradicted my original thinking. He recommemeded dumping the clutch at high RPM rather than launching at low RPM when searcing for the sweet spot. He said a 5000 rpm clutch drop will just blow off the tires, while a low rpm clutch drop risks seeing too much traction, pulling a wheel stand and smoking the clutch with big torque motors. He said said start dropping your RPM incremently until you find the traction you want and never let the tires hook after the burnout in the bleach box..go right to staging. This should save the clutch when you are at the track with slicks.

I pass on this info for the next guy who may be in my same shoes.