Clutch won't disengage

[studmobile]

I have a Harrington LeMans, and we pulled the engine/trans to replace oil seals/gaskets. Found out the original 8" clutch and flywheel were replaced by a 7.5" later version, 10 spline. Have multiple spares that came with the car, including two 8" clutch plates and covers. Decided to stay with the 7.5" flywheel and clutch, refacing the flywheel and replacing the ring gear. Replaced the disc with one from SS, but clutch cover unavailable so reused the original cover. New throwout bearing did not fit well, so reused the one in the car. Looked to have plenty of meat left. The slave cylinder was rebuilt, and had a threaded adjustable rod, not original but working fine. Used the correct centering tool to install clutch. Bled the system with hard pedal.
Finally had everything installed, but cannot get the car in gear. Adjusted the rod through entire length, and no joy. SS has no 7.5" clutch covers in stock. Will look for an original slave rod to replace the adjustable one, but any other thoughts? Will be in Columbia this weekend, and will ask the gurus there, but looks like my HLM will have to stay home. Thoughts? David

 

[sunalp]

Sounds like you have the clutch plate in backwards. Easy to do, not as easy to fix.

 

[hartmandm]

Did you reuse the pilot bearing or install a new one?

The clutch disc could be stuck to the flywheel. That happened to me when I installed an OD gearbox, but the car was sitting for multiple months when that happened.

Mike

 

[studmobile]

New pilot bearing, reused the TO bearing as it fit better. Looked at the removed disc, and significant differences between the front/back sides. Don't think we could have put it in backwards, but dumber things have been done...
Looks like we will have to pull the engine/trans, and replace the slave rod, but any other thoughts if that is not the answer? Should I seek out a new pressure plate? Have always heard you should replace the disc and pressure plate together, but looks like a new one will be hard to source.

 

[hartmandm]

Was everything working ok prior to disassemble and reassemble?

Have you visually inspected how much the clutch slave rod travels when the pedal is depressed?

I reused my pressure plate with a re-surfaced clutch disc with no issue.

I have attached measurements of my series 5 original clutch slave rod if that is of interest.

Mike

 

[studmobile]

Thanks for the measurements. Clutch was working fine prior to R and R for leaking seals. Replaced gaskets and seals and synchros. Reused the same pressure plate and TO bearing, new clutch disc from SS and new pilot bearing. I was the "foot" for the bleeding, but my mechanic felt the movement was adequate at the slave.

 

[Barry]

Is it possible that you combined an 8" clutch disc with a 7.5" clutch cover? If so, the outer circumference of the clutch disc may be "pinched" under the clutch cover housing and cannot be released. I have seen it happen.

 

[studmobile]

Is it possible that you combined an 8" clutch disc with a 7.5" clutch cover? If so, the outer circumference of the clutch disc may be "pinched" under the clutch cover housing and cannot be released. I have seen it happen.

Don't think so. Ordered the later 7.5" disc from SS. Interestingly, the box said 10 spline, but the disc was 25 spline. They checked their stock and the entire shipment of 10 spline discs were 25 spline. Someone at the source screwed up. They sent the correct one, and it matched up with the one taken out, which I remeasured. From the parts book, there was a plethora of versions of clutches. Mine started with the Harrington 8", and at some point in its life was switched to the 7.5" flywheel and clutch.

 

[Asm109]

Can you rig up a way of mechanically actuating the clutch lever? Thinking a length of all thread some nuts and large washers.

Move the arm as far as possible. See if clutch disengages. Measure travel to point where clutch disengages.
Now you have something to compare your hydraulic clutch performance with.

An if you can't get the clutch to disengage with lever fully moved till it bottoms out, then you know you have to drop the tranny.

 

[studmobile]

Can you rig up a way of mechanically actuating the clutch lever? Thinking a length of all thread some nuts and large washers.

Move the arm as far as possible. See if clutch disengages. Measure travel to point where clutch disengages.
Now you have something to compare your hydraulic clutch performance with.

An if you can't get the clutch to disengage with lever fully moved till it bottoms out, then you know you have to drop the tranny.

Thanks. Double checked with my mechanic. He stated he saw the lever move more than an inch. He could start it in gear with the clutch pushed in, but could feel a slight drag on the engine. Frustrated. And of course checking the clutch/tranny/OD is the last thing to check before driving it on the street. Will still go to the Invasion in Columbia, just not in a Sunbeam. DHH

 

[hartmandm]

Clutch engaged does create a slight drag on the engine. After starting the car in gear with the clutch engaged, he is not able to leave the clutch engaged and go into another gear?

Clutch rod moving more than an inch might be too much? Let's see what others think.

 

[DAVID LAWLER]

I had an almost identical experience using a new clutch plate and an existing pressure plate in the Orange Blossom, Series V the day before leaving for TEAE United five in Savanna. In desperation, I pulled the engine and transmission looking for the problem. Everything appeared correct. I put the old plate back in, and it worked fine. A couple of years later, the car ended up in very ugly storage where it stayed until getting ready for TEAE United 39 in Toronto. I tried to get a new slave, wheel and master cylinders from Rick. He was out of Alpine clutch master cylinders, so we installed a Tiger MC which required slightly more pressure and would give us more throw of the pressure plate. If the clutch plate was rusted to the flywheel or pressure plate; it broke free immediately with no apparent problems.

Next part – our Series Four went into similar storage, and even though this was heated, the brakes shoes and pads were all rusted solid to the discs and drums. I can not imagine that the clutch plate was not rusted to the flywheel also. I did the same thing with a Tiger MC. The clutch worked fine on the first attempt.

This has led me to believe that the clearance between the new clutch plate and the older pressure plate was very minimal, and that the longer throw permitted enough clearance for the plate to break free in spite of any rust, or dimensional problem with the older pressure plate.

If you get desperate, and you determine it to be a dimension or rust issue, you might try this or some similar means of increasing the throw of the pressure plate either permanently of just until it breaks loose. Quite a bit easier than pulling the engine and transmission.

 

[studmobile]

I had an almost identical experience using a new clutch plate and an existing pressure plate in the Orange Blossom, Series V the day before leaving for TEAE United five in Savanna. In desperation, I pulled the engine and transmission looking for the problem. Everything appeared correct. I put the old plate back in, and it worked fine. A couple of years later, the car ended up in very ugly storage where it stayed until getting ready for TEAE United 39 in Toronto. I tried to get a new slave, wheel and master cylinders from Rick. He was out of Alpine clutch master cylinders, so we installed a Tiger MC which required slightly more pressure and would give us more throw of the pressure plate. If the clutch plate was rusted to the flywheel or pressure plate; it broke free immediately with no apparent problems.

Next part – our Series Four went into similar storage, and even though this was heated, the brakes shoes and pads were all rusted solid to the discs and drums. I can not imagine that the clutch plate was not rusted to the flywheel also. I did the same thing with a Tiger MC. The clutch worked fine on the first attempt.

This has led me to believe that the clearance between the new clutch plate and the older pressure plate was very minimal, and that the longer throw permitted enough clearance for the plate to break free in spite of any rust, or dimensional problem with the older pressure plate.

If you get desperate, and you determine it to be a dimension or rust issue, you might try this or some similar means of increasing the throw of the pressure plate either permanently of just until it breaks loose. Quite a bit easier than pulling the engine and transmission.

Thanks for both of your suggestions. My mechanic adjusted the rod to both the minimal and the maximum length, with no success. It sat in a dry garage for perhaps 6 weeks after assembly. Don't know if he tried to release the clutch after starting it in gear, there was a car in front and it was frustration time. Perhaps I will try that as a last ditch effort in the am. Maybe drive the 90 miles to the Invasion in first gear?

 

[hartmandm]

I believe the rod length won't matter much to some degree, as the plunger resting place inside the clutch slave will move forwards or backwards accordingly. It would be an issue if the rod was so short the plunger ended up getting pushed out the end of the clutch slave.

I thought I had read on another thread that someone had an issue when the slave rod had too much travel, as that resulted in over compressing the pressure plate fingers and the clutch disc was then binding.

If there is a car in front of yours, but it is clear behind your car, then start the car in reverse with the clutch engaged, handbrake applied, wheels blocked, etc. That is what I did when my clutch disc stuck to the flywheel while my car was in my garage.

Mike

 

[studmobile]

I believe the rod length won't matter much to some degree, as the plunger resting place inside the clutch slave will move forwards or backwards accordingly. It would be an issue if the rod was so short the plunger ended up getting pushed out the end of the clutch slave.

I thought I had read on another thread that someone had an issue when the slave rod had too much travel, as that resulted in over compressing the pressure plate fingers and the clutch disc was then binding.

If there is a car in front of yours, but it is clear behind your car, then start the car in reverse with the clutch engaged, handbrake applied, wheels blocked, etc. That is what I did when my clutch disc stuck to the flywheel while my car was in my garage.

Mike

So I started it in gear, pedal depressed, seemed to idle fine. Letting out the clutch gently made it start forward, but it was on a lift and I did not let it move much. Tried this in both 1st and 2nd gear. If I tried to shift into another gear, got the grinding....
This is the original trans with OD, non synchro first gear

 

[windlessdog]

I think you may have a pilot bearing issue, it doesnt take much to to keep the shaft spinning which in turn will cause shift issues

 

[studmobile]

So at the Invasion in SC, which was great (thanks as always Eric) talked to lots of folks, and this is the plan. Pull the engine/trans/OD, first look to see if clutch disc is in correctly (one side says "flywheel this side"). Not sure if I want that to be so, since it would show we are nimrods, but then we flip it and reinstall and we are done. Then go on to pilot bearing. Then go through the gears/check resistance of the transmission shafts. I could put back the used clutch disc as a trial. Or could source an original size 8" flywheel and use the original type clutch cover and disc for the HLM, that came with the car.
Travel will delay this a few weeks. Thanks to all for the many ideas and patience with my problems. David

 

[jumpinjan]

I think something is in a bind, like maybe the pilot bushing & input shaft and the mating surfaces of engine block & bellhousing.. I don't think the clutch plate can be installed backwards, I don't ever remember it possibly fitting backwards.
If you have the 7.5" clutch installed, make sure the clutch release arm is the one for that clutch, and the carbon bearings are different too than for the 8" clutch.
Jan

 

[studmobile]

I think something is in a bind, like maybe the pilot bushing & input shaft and the mating surfaces of engine block & bellhousing.. I don't think the clutch plate can be installed backwards, I don't ever remember it possibly fitting backwards.
If you have the 7.5" clutch installed, make sure the clutch release arm is the one for that clutch, and the carbon bearings are different too than for the 8" clutch.
Jan

Thanks. The new carbon bearing did not seem to fit well, and also the concerns about quality in the new bearings, caused us to reuse the old one. Same clutch cover. Same slave cylinder rod, adjustable. Will update once we figure it out. DHH

 

[jumpinjan]

Make sure the two alignment pins are in place between engine block & bellhousing.
Jan