pcopp

Assisted son with T56 swap on 1986 305.

We used new LT1 flywheel, pressure plate, clutch wity new brass pilot bushing and new to bearing.

we used third gen pedals, 4th gen master and third gen slave. We used third gen slave as it was new, metal housing with bleeder.

The car shifts ok, but on full depress of the clutch, there seems to be a grinding noise. The T56 has a pull style pressure plate. Is the master/slave “over” pulling the pressure plate and causing fingers to rub flywheel.

i have a 4th gen slave on order. If we swap to that, will it help? We also have 4gen pedals if necessary.

any guidance is appreciated.

sofakingdom

iTrader: (1)

You have pretty much the same problem everybody else with that setup (including myself) has.

The 3rd gen pedals locate the MC stud too far downwards on the lever, meaning it moves too far, meaning the clutch gets moved beyond its intended travel.

You need to either instruct your driver not to push it all the way to the floor, or use 4th gen pedals.

Changing the hydraulics won't materially affect it.

sofakingdom

iTrader: (1)

Incidentally, since that's a "pull style" clutch, the TOB doesn't "push into" the clutch against the fingers. It "pulls out". The noise it makes is from the "fingers" of the diaphragm (return spring) scraping against the front of the transmission's clutch gear bearing retainer.

In any case, no clutch makes noise from the "fingers" "hitting the flywheel". Those 2 things are bolted together, therefore move together and cannot "rub".

pcopp

Thanks. We certainly understood that it was a pull style clutch. Did not consider that it was the fingers rubbing on
the input shaft collar. Makes sense.

We will work tonight to swap entire pedall assembly from 3rd gen to 4th gen (or at minimum the clutch pedal if we can). Will report results when complete.

sofakingdom

iTrader: (1)

It'll have to be the whole assembly. Well, maybe not... maybe you can take out the one that's in the car, disassemble it, disassemble the other one too, reassemble the one, and put it back in... I don't know, and wouldn't do it that way, regardless. I CAN tell you however, you can't get the clutch pedal out with the assy still in the car, because there's not enough room for the pivot bolt to slide out far enough to let the pedal come out. All of that disassembly and reassembly stuff in between "take it out" and "put it back in" seems like a wholelotta extra maze with no cheeeezze at the end.

It's real eeeeeeezzzzy to swap the whole assy out anyway. 4 nuts hold it to the firewall, 2 clips hook the pedals to the MCs, the brake light sw, NSS, & cruise sw all pop right off or unplug. In out done. It's only an hour or 2 of work counting stops for refrigerated adult beverages if you're slow like me, but you're almost certainly faster and smarter than I am (everybody is), so you can probably do it ALOT quicker. You'll need to either adapt the gas pedal to the 4th gen system (NOT eeeeezzzy as I understand it) or just cut that part of the assy off and leave the existing gas pedal in place.

Manual transmissions don't have an "input shaft". The part that looks like it would be that, is called the "clutch gear". The piece that retains its bearing is the "clutch gear bearing retainer".

TimothyFox

The grinding noise on full clutch may be due to the pull-style pressure plate. Swapping to a 4th gen slave and pedals could help reduce the pressure and resolve the issue.


pcopp

So, we pulled transmission last night.

When clutch is depressed, the clutch fork is rubbing the edge of the pressure plate.

So we are using all LT1 parts (master/slave) and of course new Flywheel, Clutch Disc, Pressure Plate, Pilot Bushing and TO Bearing.

I can only surmise that although the LT1 Flywheel fits on a one piece RMS 305 SBC, that there is a small difference in the clearance from face of pressure plate to transmission face and that results in the rub.

We saw another post where a person with a 305 SBC Monte Carlo did the same swap clearanced the clutch fork where the rubbing was occuring as well as shortened the clutch fork Tee post.

We opted to just clearance the clutch fork generously where it was rubbing at my buddies machine shop last night.

We hope to assemble tonight and will share results either way when we get it back together with pictures.

pcopp

OK, problem is solved. When we pulled the transmission, we observed that the clutch fork was rubbing the edge of the pressure plate (see pic)


We could see the rub marked on the edges of the clutch fork. So went to my buddy who is a machinist and he milled out the edge of the clutch for to clearance where the fork was rubbing the pressure plate. The form material was hardened steel so it was good to have access to the milling machin. We took this muchmaterial off (see pics)



Problem solved. We reassembled and the clutch operates properly with no rubbing. Parts installed on car are as follows

Third Gen Pedals (no wooden block or other device to limit travel)
Fourth Gen Clutch Master
Fourth Gen Clutch Slave
Fourth Gen LT1 fly wheel mounted on 1986 two piece RMS 305
Fourthe Gen Clutch Disc
Fourth Gen Pressure Plate.

Everything works well with full clutch pedal travel.

We installed Accutach VSS/OSS device to run the reverse lockout solenoid off the speed sensor to protect trans from misshift when in motion.

grove

iTrader: (3)

Pcopp, thanks for posting pics of the clutch fork. I'm about to install a T56 in my 88 bird. I'm going to use 3rd gen pedals with 4th gen hydraulics. I tried 4th gen pedals but the holes for the clutch master cylinder didn't quite line up had to muscle fuq it in. also the pushrod for the clutch master cylinder with 4th gen pedals had a bad angle on it once I hooked it up. So I threw in my 3rd gen pedals and everything bolted up easier and the pushrod is straight, no angle. But I was worried about potential rubbing like you had. With you posting pics of your fix, Think I'm gonna follow in your footsteps. I don't want to be pulling the transmission again for awhile since I don't have access to a lift.

pcopp

grove, son has been driving the car for two weeks no with no problems. I can only assume that the 1986 SBC with one piece rear main seal crank must cause the flywheel to protrude into the bell housing that little bit extra compared to the 1995 LT1 one piece RMS crank that results in the rubbing of the pull fork on the pressure plate. You can see how much we ground off of it and now it does not rub (of course we knocked the corner off the pressure plate with the original interference).

The borg warner fork for is pretty beefy and we certainly could have taken more off without weakening the fork.

I would clearance it generously to avoid doing it twice.

We have a lift in our home shop, but the real PITA is disassembly of the console and wiring every time we want to remove the transmission gear shift boot to drop the trans.

We are running third gen pedals with 4th gen hydraulics. The other PITA is bleeding the clutch. With the 4th gen setup, there is no slave bleeder (3rd gen had one) so my son patiently bled the clutch using vacuum pump.



Good luck.

pcopp

Also, there are two upper ears on the T56 transmission at 10:00 and 2:00 o'clock that interfere with the trans tunnel and on the 1986 carbureted 305, the fuel lines hug the top of the trans tunnel.

We saw no reason to keep the ears on the trans so we cut them off and it was so much easier to get the trans into the pilot bushing.

Ironically, we saw the latest episode of Bitchin Rides and the Kindig it crew had to cut the ears of the tremec T56 to get the trans into a 1988 Mustang. So it seems to be a common problem/solution.

Hate to be under car on my back fightin those ears. Good luck.