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Triumph TR6 - Clutch binding when hot

I experience an increasingly annoying problem and could use some advice.

The clutch of my 74 TR6 operates fine and fairly smoothly when the engine is cold. After an hour driving some binding might occur when releasing the clutch. When I get home after a two hours drive the parking of the car in my garage becomes a hazardous operation. I need to park close to the wall clearing bicycles and other stowed goods. When the engine/clutch/gearbox is heated through and through a slow entrance of the garage becomes though to accomplice. Crashing into her bike will not please my wife and will damage my ego.

I might use the winter period trying to fix this. Any idea’s how to proceed?
I do not want to pull the box without a solid plan.
Erik Creyghton

Erik,

I take it that this is a recent deevlopment and that not too long ago averything was fine.

I would check the following

1. Bleed the clutch slave cylinder. Maybe even rebuild the clutch master and slave cylinder. It might be possible that the system has swallowed some air that affects the travel of the clutch and as it heats up it doesn't have the throw distance to completely disengage the clutch.
2. On the rod from the slave cylinder that engages the clutch, try a different hole to get more throw distance.
3. Check the clutch shaft bearings (shaft that goes through the transmission housing). If these are worn they may affect the ability to disengage and it might get to sloppy as it warms up. The shaft will have a lot of forward and back play.
3. Check the crankshaft end float. If the end float is too much (meaning worn or thrown thrust bearings) it may affect the ability to disengage the clutch when warm. If the end float is too much. it means an in situ replacement (underneath by removing the oil pan) or pull the engine.
4. Pull the tranny off and inspect the clutch bearing and clutch plate for wear.

If the above doesn't find the problem then I would go back to the BBS.

Regards
Mike Petryschuk
Michael S. Petryschuk

Mike,

The clutch will disengaged fully under all circumstances.
I also consider the travel of the throw distance to remain the same in cold and hot conditions.
I guess that rules out air in the system and thrust bearings on the crankshaft.

When all is heated-up it feels like the clutch pedal will stick in its down position and jerk in its travel up. The ability to dose the clutch has never been the strongest design of the TR6.
The clutch shaft bearings will have my first attention.
I assume you can feel any play on the shaft form the outside.

Erik
Erik Creyghton

I wonder if your throw out bearing sleeve is snagging on the snout as it comes up to temperature. Since your problem seems to be happening when things are warmed up good, I would look for tight clearances where metal expansion could play a part.

The return action of the pressure plate diaphram spring should be plenty to help push the clutch pedal up from its lowest position near the floor.

Also make sure the mechanicals on the pedal box and clutch pedal move freely and without bind. You will want to put some side-to-side and up-and-down pressure on the clutch pedal to see if it moves freely in the pedal box.

Good Luck
MRankin
MRankin

Erik,


I don't know for sure I've had the same problem: when hot, it was hard to shift gear to gear (clutch not fully engaged). When standing still the car kept on moving like the clutch was half in.
Replacing the clutch slave cylinder solved THIS problem for me.

Good luck.
Eric
Eric de Lange

Check the clutch linkages where the clutch pedal is connected at the front end of the master cylinder. I had a case where my clutch pedal would not come back smoothly. I took apart the link between practice sessions when I was at the TR races at Virginia International Speedway in USA. No, I was only a spectator.

The cross link looked like a little crankshaft. Normally the diameter of this link is about 1/4" and it was worn about 3/4 the way through. I replaced it with a new spare I had with me and this corrected my problem.

Don Elliott, 1958 TR3A
Don Elliott

Erik,

It has to be the throw-out bearing carrier hanging up on it's slide. Only remedy is to R&R the gearbox and hone the slide. In the meantime, drill a couple of very small diameter holes in the bottom of your flywheel housing approximately beneath the T/O bearing. Spray some lubricant up there (silicone comes to mind) and some of it will hit the carrier. If your garage floor is flat, just coast in there and push the TR home. I do that every day!

Rick O.
Rick Orthen

The pedal box is in a sound condition, I lubricated the sleeves on the pedal shaft without results.

Next I will inspect the clutch linkage mechanism for any play or binding.
I fear however the problem will be in the travel of the throw-out bearing.

Although the idea is creative to spray some lubricant inside one will run the risk to lubricate the friction plate in the action.

Most probably the gearbox has to come out.

Erik
Erik Creyghton

What else is there to do in the "Neverland" in the winter.Hope your garage is heated!
DON KELLY

This thread was discussed between 27/11/2006 and 29/11/2006

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