General Tech No Triumpn - Healey 3000 Clutch not engaging

[RonR]

Folks,

The clutch on my Austin-Healey 3000 does not seem to engage.
I amposting here and on teh Healey forum for greater exposure to this strange problem.

I pulled out of my garage and everything was fine. The car died while waiting for the garage door to close. When I restarted it and put it back in gear, the car would not move in any gear. I can shift into all gears with the engine running. Under car observations verify that the slave cylinder is working and the rod moves at least 5/8 inch.

With the car on jack stands, I started the engine and let the clutch out in all gears. The rear tires only turn when the transmission is in 4th gear, and they do not seem to be turning very fast. Putting on the brakes with the transmission in 4th gear and the engine running does not reduce the rpm at all.

The clutch can and pressure plate have around 22,000 miles on them. I can’t believe anything is worn out with such low miles, especially when things stopped working all of a sudden.

Any thoughts would be greatly appreciated.
Ron

 

[TR3driver]

Just to eliminate any chance of it being a hydraulic problem, I would disconnect the pushrod at the slave (or remove the slave) and re-check. If it still isn't engaged, then something is broken inside and will no doubt be obvious after removing the gearbox. If that does get the clutch to engage, I would suspect that for some reason your master cylinder is not returning all the way (misadjustment, sticky pedal, etc) and not opening the return valve to the reservoir. That can cause it to hold pressure in the system all the time, even though the motion appears normal.

FWIW, several local TR6 owners have suffered similar problems caused by a failure of the friction plate. Relatively new plates (less than 10,000 miles IIRC) failed where the thin spring metal that carries the friction material is attached to the hub. Both of the owners I spoke with described it as a sudden failure. My assumption is that they got defective parts, but I didn't see the evidence, just repeating the stories.

 

[RonR]

I disconnected the slave cylinder from the clutch fork, which indeed verified it is not a hydraulic problem.

Removing the transmission is the next step; a very long frustrating step. Similar to my TR3A, the carpet, seats, and transmission cover must come out.
I do have an engine hoist, so lifting is not the problem. However, things are a lot tighter clearance wise in removing the transmission on the Healey than on the TR3A.

I will be interested in discovering what happened since it was not a gradually occurring problem.

Thanks for your advise, Randall
Ron

 

[Marvin Gruber]

Does the pedal pressure feel the same? Maybe take a rubber mallet and hit the clutch fork a couple of times. If it was working fine when it died and then the fork or throw out bearing cocked or hung up in depressed state.
Marv

 

[Jerry]

I will follow this thread since my neighbors MGBGT did exactly the same thing. He drove the car 100 yards, went back to it 3 hours later and letting out the clutch does not make the car move. Something is stuck!

 

[RonR]

Marv, the clutch fork is loose, in that it has the correct amount of free play (in and out) when disconnected from the slave cylinder push rod.
I will try the trusty hammer fix and if that does not solve anything, I will pull the transmission in a week or so.

 

[Sarastro]

The Healey 3000 pressure plate has release fingers, doesn't it--i.e., not a diaphragm clutch? In many of those, the fingers are held on by nuts that can come loose. In my Bugeye Sprite, the clutch did that. I readjusted it, wrapped the locking washers nice and tight around those nuts, and a couple years later it happened again. That time, I welded the little suckers. No more problems after that.

Anyway, you'll probably end up pulling the transmission, and you'll find out what happened, so all this is just speculation.

 

[busybrit]

How old is your clutch hose to the slave cylinder. A customer of mine with a BJ8 had the same issue, it was the hose bore which had collapsed not allowing the built up pressure to return to the master cylinder, essentially keeping the clutch under pressure.

 

[sp53]

Well if you pull the hydraulics and the clutch is not in on position, like you said out comes the trans

 

[TR3driver]

Removing the transmission is the next step; a very long frustrating step. Similar to my TR3A, the carpet, seats, and transmission cover must come out.
I do have an engine hoist, so lifting is not the problem. However, things are a lot tighter clearance wise in removing the transmission on the Healey than on the TR3A.

Trust me, it could be worse. The Stag is unibody, so there is no cover to remove. To pull the gearbox without the engine, you get the car way up in the air, take everything loose (including exhaust and radiator hoses) and then remove the rear crossmember and let the engine hang from the front crossmember. It only comes down a little, so there is only a narrow gap between the gearbox and body that you have to reach through to access the nuts & bolts. My arms don't fit into the gap very well, every time so far I've wound up bleeding from trying to force them in there!

 

[RonR]

Randall, there is nothing like blood caused by a British car. I leak the red stuff just from cleaning the engine compartment. My TR3A causes less blood.

I hope to have the transmission removed by Monday, February 6, and will report back.

 

[Alfred E. Neuman]

Trust me, it could be worse. The Stag is unibody, so there is no cover to remove. To pull the gearbox without the engine, you get the car way up in the air, take everything loose (including exhaust and radiator hoses) and then remove the rear crossmember and let the engine hang from the front crossmember. It only comes down a little, so there is only a narrow gap between the gearbox and body that you have to reach through to access the nuts & bolts. My arms don't fit into the gap very well, every time so far I've wound up bleeding from trying to force them in there!

That's how nearly every Mercedes transmission I deal with comes out. The bell housing bolts at the top are a real pain. I've got two 3' extensions for 3/8" ratchets just so I can put swivels in between them and come at them from nearly the back of the car to get a good straight shot onto the bolts. One extension goes onto the bolt and out to the back of the transmission, swivel, next extension angles down to the ratchet. I'll fish my arm up to the bolt and feed the first extension in with my other hand, then have someone pop the other extension/ratchet on and loosen or tighten the bolt as needed while I hold the socket in place. Good times.

 

[RonR]

I pulled the transmission the other night.

There is nothing obvious wrong with the clutch or pressure plate.
The clutch disc is more than thick enough to clear the rivets on both sides.
One of the small springs for the release levels on the pressure plate was slightly bent and not fully engaged, but I don’t think that would have caused the instant problem of the clutch not engaging when the clutch pedal returns.
The release (throw-out) bearing looked great.
The flywheel is quite smooth, and probably should be resurfaced.

I was thinking that perhaps the problem is in the rear axle. With the car on jack stands, turning the differential does not turn either rear wheel. Turning the driver’s side rear wheel turns the differential. However, turning the passenger side wheel does not turn the differential.

The differential was rebuilt in September 2006 by Healey Surgeons

Any thoughts would be greatly appreciated.
Thanks.
Ron

 

[TR3driver]

Does the driver's side wheel turn when you turn the passenger wheel? If turning the passenger wheel doesn't move either the driveshaft or the opposite wheel, then I'd say you've found the problem. But it's not unusual for the opposite wheel to turn instead of the driveshaft; just depends on which has more drag.

 

[RonR]

Neither the driver's side wheel or the driveshaft turn when I turn the passenger's side wheel.

If I have foun the prolem, what is it most likely to be?

 

[TR3driver]

Something broken inside the axle housing. I don't know Healeys at all, but my WAG (wild ass guess) would be the shaft broke at the splines.

This is a Sprite rather than a 3000, but shows the kind of damage I'm imagining.

 

[RonR]

I have seen the Sprite shaft problems many times on friend's cars.

It does sound like my car has the passernger side axle broke. I am heading out to remove it now.
The next question will be, if it is broken, do I replace both 57 year old shafts or just the broken one?

 

[TR3driver]

My inclination would be both of them. Most likely a metal fatigue issue, and they've both seen very nearly the same stresses for all those years. You might get a few more years out of the other one, but why take the chance on having a trip interrupted when it eventually does fail?

 

[RonR]

New axles ordered.