FrankieD

I have been researching the market for a Twin Disk clutch setup for the Zf6 transmission and its been a rollercoaster ride as to what people are using , what their use is for; such as drag race only , DD only , or a combination of both. I would like to compile a list of users and have the following questions answered for others in the future trying to make a similar decision.

Clutch Manufacturer and Part # (Also Disk Friction Material if known)

Useage Type; ( Drag only, Daily driver only, or both)

Your Hp / Tq numbers ( Rear wheel or Flywheel )

Push or Pull style clutch

Type of Master (stock or other)

Driving Experience / Impression (Clutch feel experience . any chatter and are you able to slip the clutch during normal driving. stop n go traffic experience)

Installation details or tidbits .( any special or unique tidbit info during installation )

Now the last point is to detail any driveline damage that may have occurred during use of clutch. If you experienced any driveline damage please list damaged components and how the car was used whenever the damage occurred, such as aggressive launch, normal daily driving, or other. This is to clarify all the of the reports of damage to driveline due to clutch shock during engagement. Need to clarify if this damage is occurring during normal everyday driving or during extreme race conditions. hard launch , sticky tire etc..

Perhaps this can be made into a sticky if we get enough entries.

Thanks for contributing your info to the forum for everyone to share.

tpi 421 vette

I have a McLeod dual disc in my 91 with stock type organic lining discs. I put it in back when I had a 421 in the car. That engine made 720rwhp and 790rwtq. Before I put it in, I had a Spec stage 3+ clutch. It worked well but finally wore out as the car started running 10.80 to 10.70. I didn't break anything at the track with a 26" ET street. Then when I put in the dual disc, I started breaking everything. 3 half shafts, 1 spindle, and finally broke the whole D44 housing in half. There is no slippage or cushion when you dump the clutch. They will shock the parts. I would probably stick with a single disc clutch if you drag race it with sticky tires. I now have a Ford 9" with Strange 35 spline axles and spool, and the car now runs 1.3 60ft's and doesn't break parts. The McLeod dual disc is a pretty bullet proof clutch, if the rear end can take the shock of it. But they will break stock IRS parts. But the drivability of a DD clutch is like a stock clutch. Very smooth, not grabby. It feels like a stock clutch.

FrankieD

would like to get some input from other Twin Disk clutch users if possible

LTxDave

My McLeod street twin drives good, pedal pressure is fine, but it is too noisy for what I want out of the car at this point. I am seriously thinking about going to a different clutch once I get this thing tuned. The one I have came with a steel flywheel and different master cylinder.

FrankieD

How is the clutch for daily driving,stop n go traffic? can it be slipped or does it have a on/off feel?
Is this a Push type conversion or the original Pull type style like factory

MatthewMiller

I think the noise is always going to be a function of the single-mass flywheel and the ZF transmission's bearing lash. The dual-mass OE flywheel is the way to get rid of it, but those are expensive and hard to find, and probably not compatible with your twin-disk clutch. And your car would be noticeably slower with the 40lb dual-mass flywheel unless your steel flywheel is nearly that heavy also.

tpi 421 vette

I drove my car when it was more of a street car with the dual disc. And the drivablity was perfect. It felt like a stock clutch. You can slip it some if you like, just like a stock clutch. It's doesn't have that on/off feel to it at all.

LTxDave

It is pretty much like the stock clutch for drivability. It's not heavy or anything. Mine is the factory pull style clutch. The only differences I can tell between this and stock are the noise and if you are really sloppy with gear changes, you can tell there is no spring on the hubs. I believe more noise comes from the unsprung hubs than anything else.

FrankieD

I've noticed that Spec and Ram convert to a Push type clutch. I believe when Mcleod originally released the Twin disk for the ZF6 it was a Push type; however their current model is a Pull type. My question is why the change and is there anything advantageous from either of them.

hcbph

Frankie

I don't apply here but love reading stuff like this for information. Might it be worthwhile to also include particulars on the flywheel if it's been replaced? Might have some bearing on the results you get, especially if not factored in.

Just a thought.

MatthewMiller

Flywheels are simpler than the clutch designs and materials. Single-mass (virtually any new replacement) is noisier. Lighter is noisier, more responsive, but harder to get rolling from a stop smoothly. I believe the RAM setup requires the use of its own flywheel: you don't have a choice. Not sure about the others.

KSA Aaron

McLeod Twin Disk with aluminum flywheel. Street, drag and roll racing. Noisy like all ZFs that have the dual mass flywheel removed. The McLeod Twin Disk pedal feel is as light as stock, and can be slipped a bit on take-off.


I ran a Spec dual prior until it came apart. McLeod is a MUCH better design.

FrankieD

Was it a Push or Pull style setup? Also, was the Friction material Organic?
Thanks for your contribution to this post

KSA Aaron

OEM style "pull-type" clutch activation.


'87 Vette, McLeod clutch master, McLeod aluminum flywheel, organic disks, '96 OEM slave and hydraulic line, '90 black tag ZF, and '96 OEM bellhousing.


The combo works....

FrankieD

Great detail !! That's exactly what this thread needs.

If we can get other members to contribute as well , that would be fantastic

FrankieD

Looking for the Installation instructions that comes with the Street Twin Clutch, Anybody have a copy or link to them?

dizwiz24

Old thread i know

but it seems like the problem with dual clutch disk setups (and why they are noisy/break parts) are because they dont have a sprung hub (for those who have gotten rid of the heavy factory dual mass flywheel)

that said, prove me wrong:
does anyone make a dual disk clutch (for zf6) that comes with a sprung hub?

rklessdriver

No, the noise is transmission gear train noise.

It's caused because of the uneven firing pulse of a 90* V8.... the heavy dual mass flywheel gives these engines extra momentum at idle, which smooths out the firing pulse, so it dosen't backlash the transmission gear train as much. Ford used the same dual mass flywheel system on the old 7.3L diesel as well... which also used a noisy rattling ZF built transmission incidentally.

A sprung disk hubs main purpose is to absorb chatter during clutch engagement.

Reduce flywheel mass and the firing pulses become more evident... Most people can now hear the transmission at idle. Just wait till you hear a ZF6 behind something with an aluminum flywheel and big cam.... its really loud. My old 92 6spd would drown out a Semi idling next to you at a stoplight.
Will

KSA Aaron

I can vouch for the above comment from rklessdriver, my 408 with large solid roller and McLeod twin is quite noisy. Although the exhaust tends to drown out the gearbox rattle.

MatthewMiller

A ZF6 with solid flywheel is even louder if you use a non-sprung disk (the kind that came with the OE dual-mass flywheel) in front of it. Using a sprung disk won't silence it, though.