cagotzmann

I would like to express my disapointment with the Mcleod RST Twin disc setup in my 78 with a T56 6speed.

2 things I am disappointed about.

1 the noise, and 2 the noise.

With the car out of gear and the clutch released the twin disc's rattle and during accelleration I also get a noise at 2500 RPM.

I spoke to Mcleod and they said that's because the disc's (twin setup) do not have springs (in the disc) to absorb the transmission and engine harmonic's. Some cars you wont hear the noise and others with less sound barriers between the transmission and the body you will hear the noise.

It happens in every gear 1st-4th at 2500 RPM when you accelerate any amount. I didn't test 5th or 6th.

I guess I should have checked with google about the bad of most twin disc setup's.

I went with twin to get a light pedal feel.

As for the clutch working, the pedal feel is nice and light, shifts are very smooth. The engagement point is higher than I like compared to the original single disc but I would not have chosen the Mcleod twin disc had I known about the possible noise issues.

Silvertone

That's exactly the clutch I'm using along with a Hays billet flywheel and a Keisler SS700 5spd. No noises here.

Have you heard of others also having this issue? I'm not buying their explanation, unless you have some extreme vibration or balance issues. This was a very well rated clutch at the time I bought it in 2013.

Metalhead140

Can't imagine why you would have a clutch noise while accelerating? My mates triple plate clutch makes rattling noises when released (pedal pushed in) also, so not overly surprised by that, though the twin plate in my f250 is silent.

65-StingRay

My RST works quite well. No noises, no problems - got about 1500 miles on it.
Hope it's something that can be diagnosed.

65-StingRay

427Hotrod

Something doesn't sound right. I've used those in a couple of builds with no noise issues.

JIM

cagotzmann

I wish McLeod was more helpful.

I may just put back my single disc
and see how it goes

C3Paul

I also have the RST and Love it!
No Noise, light pedal, no vibrations..

Be fair the clutch is either ON or OFF when it bites, but overall, Like it.

gkull

Read up on drive shaft angles from tranny output to pinion. I ended up installing a one inch block spacer under my tranny tail shaft.

http://www.iedls.com/asp/admin/getFi...&TID=28&FN=PDF

cagotzmann

I should not be a angle problem since it didn't make the noise with the ACT single disc with GM Flywheel in place. Only changes made were RAM 2540 alum flywheel with the RST twin disc clutch.

No vibration's , No shifting problems, just noisy on acceleration @ ~ 2500 RPM.

cagotzmann

Well I have 2 out of your 3. Light pedal, no vibrations, just noise.

zwede

When does it start making the noise? You say "released", so it's quiet with your foot off the pedal, and then at some point when you press the clutch pedal the noise starts?

I had a loud rattling noise with the pedal all the way down. Turned out I was over-extending the clutch. I switched to a larger clutch slave cylinder (less travel), and that fixed it.

McLeod RST, Tremec TKO.

cagotzmann

No I would put the car in gear. 1st - 4th Cruse @ 1500 RPM then accelerate to 3000 rpm. at 2300-2500 RPM I can hear what sounds like a rattle noise / bad bearing type of noise. Easiest with 3rd gear as it doesn't accelerate past the RPM as quickly.

The only changes with the before and after is the clutch and flywheel combo. everything is the same.

cv67

So the flywheel is the same as before the new clutch?
Is it an alum lightweight one?

Positive nothing on top of the trans is touching the tunnel under accel?
Had a similar issue only in 6th one of the bosses (upper left on top) was just barely touching and gave off a bizarro harmonic frequency through me off for awhile. HAcked that sucker off and alls good.

How much power are you making do you need a twin disk?

cagotzmann

previous was a ACT Single disc with the stock ZZ383 GM cast flywheel.

Now Mcleod RST with a Ram 2530 Alum light weight flywheel.

Stock GM ZZ383 HP. Went to twin to lighten the clutch feel. The ACT single disc was very heavy for me.

Nothing touching the tunnel, you can hear the noise from outside of the car.

Gale Banks 80'

What You are describing is what happens when people go to an aftermarket Clutch and Flywheel when they have the GM Duel Mass Flywheel set up to begin with. This is typical with the C4 ZF Trans. Are You sure You have the T-56 ?

cv67

Esp with al alum FW.
Some, even with the dual mass made noise but that was an issue wiht the trans itself. Didnt hurt anything just made noise.

From reading ops post sounds like its a real clutch noise and not detonation. Hard to figure that one over the web

Thats a good strong clutch at least theres no worry about slippage

cagotzmann

Tremec TUET11009 Stamped on the transmission (t56 Magnum).

cagotzmann

Here is an update with the RST Twin disc noise. (gear rattle)

This is what is sounds like.


1st change. Replace Ram Aluminum flywheel with the original GM Steel Flywheel. 80% noise reduction in the 2000-2500 RPM range in all gears. I can still hear it only if you know what to listen for.

2nd change. Replace Clutch back to ACT single disc + Ram Aluminum flywheel I cannot hear any noise (gear rattle) at all.

So its the Mcleod Twin disc causing the gear rattle noise.

Why does it make the noise. I believe its because the twin disc doesn't have any spring dampeners in the disc's which is used to soften the engine pulses and prevent transferring the pulses to the transmission gears.

The single disc has spring dampeners and therefor much reduced gear rattle. Also the heavier flywheel also helps to reduce engine pulse transfer due to higher inertia due to weight.

So the right combination of light weight flywheel, no clutch disc dampeners and a transmission sensitive to gear backlash you may hear a noise that sounds bad and destructive.

cardo0

Roller pilot bearing?

cagotzmann

Yes