Problems with Quartermaster clutch in a T56
 

Having some problems with my clutch and looking for some ideas before I open it up.
It is Quartermaster 8.5 inch double disk setup. This clutch has been discussed plenty in this forum. Probably less than 3000 miles on the clutch and T56 setup. The same setup that Howard Coleman described in the 3rd gen forum https://www.rx7club.com/3rd-generati...500-hp-905977/
I've been noticing lately that the clutch started engaging more at the top of the petal stroke. No slipping though, Making about 700whp in a 3 rotor car.
I went to the drag strip for the first time with this setup. I launched at about 6k and had some wheel spinning but then could barely get the car to shift through the gears.
At the end of the track, I couldn't get the clutch to disengage. I let it cool and tried to drive it home from the track. I had to start the car in 2nd gear cause the clutch wouldn't disengage. The cluch petal felt the same as always and had plenty of fluid in the reservior but the clutch wouldn't disengage.
So I drove home shifting without the clutch disengaging and just rev matching. After about 3-5 miles in 3rd gear, I noticed that the clutch was disengaging now to be able to shift. However, now, the clutch starts engaging near the bottom of the stroke wheras before it was at the top of the stroke.I can feel vibration in the clutch petal. The next day, I started the car and was able to drive it but something is obviously wrong. I haven't accellerated hard but I don't think there is any clutch slipping. The clutch engagment is still at the bottom of the petal stroke.
I assumed at first that I welded my clutch plates together. I thought it was odd that it started working.
I'm gonna tear it down soon but just curious if other folks have run into this issue.
Thanks,
Bobby

as you use the friction disc material, your clutch fingers will be farther away from the throw out bearing surface. This will make disengagement progressively more difficult.

You would need to shim the throw out bearing and reset the finger-TO bearing gap if what I am describing is your problem.

Hey vincent,
Did you ever figure what happened with your clutch problem?

HI Bobby,
GM type TOBs require perfect installed height, no leaks and if they are adjustable IMO require Loctite so as to maintain the correct height. It appears to me if your clutch now requires a deep pedal that you either have lost some fluid or the O ring in the TOB has developed a leak. i suppose it could be your master cylinder but is more likely your TOB. While i still consider Quartermaster highly i developed a slipping clutch, had it rebuilt and it continued to slip. Weird because for a year it worked fine.
i have since switched to a Mcleod double RST and it is heaven. an easy pedal and feather engagement. i have, however, had problems w their TOB and will be swapping in a good old Tilton this winter.
pls let us know what you find.

x2 McLeod RST or RXT for those putting down a bit more power + Tilton TOB is the way to go. This is what we've done on all the local LS swaps (usually S13/S14 chassis) and a few Gen V Camaros.

Well, The fingers on the clutch were badly worn. As I mentioned, it felt like lately the clutch was not fully disengaging and apparently that was the fact. I had some clutch material welded to one of the floating plates. This happened at the drag strip I think as a result of the clutch fingers losing much of their strength due to the wear.

I think part of the root cause was I did not have a clutch petal stop. I understand this can damage the ToB and the clutch by over extending both. Now that I type this, I sent the ToB itself (only the bearing not the back to QMaster and they said it was fine. I question the base/diaphragm assemble.

I have the ToB mounted to the adapter plate and the plate mounted to the bell housing. I am going to install the clutch, install the bell housing and check clearances. I can actuate the clutch and recheck the clearances,

Any other suggestions?????

Sorry for the delay in replying to this thread. Between lots of travel for work and several other cars needing attention, it took a while to get this car on the lift and torn down.

Thanks,
Bobby

Awesome! Good to know you are working on the matter, definitely keep us updated. I' sure these are problems I'll run into at one point...