Help, clutch/release brg/pintle problem

[Dave Bilyk]

On the way down to Goodwood, there was a squealing noise when the engine was started from cold, and I put it down to water pump belt slip. I thought I would deal with it later. Once warm no noise. I drove the car hard on track and it was faultless and didn't change the symptom. Topped up with fuel and set off for the Midlands, parked at Warwick services for a break. Started the car and moved out of the car park to the fuel station and saw significant smoke from the clutch area. I had some initial difficulty selecting gear, and severe squealing noise when depressing clutch. Went onto motorway and kept in 5th gear, squealing noise there 90% of the time. I got to my half way point by changing gear without clutch, hoping not to stress things, but I had to stop at a couple of traffic lights, and the clutch felt normal without any additional noise but noise is continuous.
What do you guys think this is?

 

[Ian Anderson]

On the way down to Goodwood, there was a squealing noise when the engine was started from cold, and I put it down to water pump belt slip. I thought I would deal with it later. I drove the car hard on track and it was faultless and didn't change the symptom. Topped up with fuel and set off for the Midlands, parked at Warwick services for a break.

And?

Do not leave us hanging on a good story

Ian

 

[Keith]

Is this the 'other' thread? :idea:

 

[Ian Anderson]

Throw out bearing cried enough?

Pity my car is not 302 or I would strip it to get you parts for trip back to Scotland

Ian

 

[Mike Pass]

It could be that there is not enough clearance between the bearing and the clutch so it is under constant load and it getting too hot and is then squealing as it burns away the grease and dries out. Check that you have clearance between bearing and clutch when released. I have a means of adjusting the free play using push rods of different length and using washers to pack out the slave cylinder. Mick Sollis does an adjustable rod for this purpose.
Cheers
Mike

 

[Dave Bilyk]

Ian, thanks for that. I was having some issue with the tablet and had to finish in edit mode.
Mike, thanks mine uses washers too, I set them appropriately, but I will investigate later today.
With engine off, the clutch feels completely normal, no noises when depressed.
There was no clutch slippage.
The other thing I will check for is leakage in case it is a gearbox shaft seal issue.
There is certainly something rubbing or turning that shouldn't be, on the motorway the noise would persist for a few minutes then go completely silent for a maybe 30 secs and come back.
Keith, yes it is the other thread, tiredness was taking over at that point!

 

[Dave Bilyk]

Mike spot on, removed cylinder, no squealing , so need to shorten pushed. Why it tightened up I don't know. Then replace release bearing at home. Thanks

 

[Ian Anderson]

2 washers under the cylinder mounting points do the same as chortening the push rod

Worked a treat in an old Truimph GT6 many years ago - noisy 500 miles from home!

Ian

 

[Ian Anderson]

come to think of it

Have you just tried bleeding it? Perhaps some crud at Master end stopping the fluid return to the reservoir

Ian

 

[Dave Bilyk]

Ian, thanks, washers in is same as lengthening pushrod, reducing clearance. Unfortunately I have no washers to remove so need to shorten pushrod. Your point about crud will be worth a try before I go ahead with a hacksaw, I think Mike's comment about an adjustable one is worth doing later too to save future hassle.
DaveB

 

[SteveB]

Dave

There are couple of ways to deal with the clutch release arm / hydraulic cylinder. There is need to make allowance for the clutch pressure plate fingers sitting further out as the clutch disk wears.
It's been the case when there is insufficient clearance inside the bell housing that the release bearing can not retract far enough causing the clutch to slip. Likewise for the actuating arm/lever the in the released position, this will change as the clutch wears.

Some manufacturers use a long bore slave cylinder and allow the piston to find its position by residual fluid pressure or a light spring inside the slave cylinder, this method has the release bearing in light contact with the clutch fingers. In effect this is self adjusting. As the wear takes place the piston finds its new position with virtually no free play. The release bearing will be constantly rotating on a light load when the clutch is engaged.

An alternative is to have the slave cylinder piston retract fully in the bore, by means of a return spring drawing the clutch lever back. This method needs for there to be some clearance play that will be taken up as the clutch wears, the clearance needs to be maintained checked and reset regularly or the clutch will start to slip if this clearance is lost. This method is not self adjusting and an adjustable length pushrod is necessary; however when engaged the release bearing is not quite in contact with the clutch fingers and has minimal load and may not rotate until the clutch pedal is depressed to actuate the lever.

Both methods work OK on lots of different cars, you just need to be sure of how the changes due to wear are dealt with in what you have.

Steve

 

[Dave Bilyk]

Thanks Steve, that's very informative and I had assumed that wear would gain clearance but you showed me that wasn't correct. My slave has a light spring to maintain a small load, the master has a stronger return spring. I did some checks and found that after operating the clutch there was still residual pressure in the line as fluid spurted out when I opened either bleed. Even when I released the residual pressure in this way the clutch did not release so I think there was a combination of sticking at both ends. I dismantled and cleaned both, the master was pretty gunky, and I reset them with minimum pedal travel. The release bearing is done, so squeals like mad when the clutch is depressed but all goes quiet on release, I feel it will get me home with minimum clutch use. It's fairly easy to change gear without using the clutch while on the move so that will help.
As always thanks for all your help Ian, Mike and Steve. Will set off for home tomorrow morning and will let you know how I get on.
DaveB

 

[Dave Bilyk]

I got the gearbox off today, as suspected release bearing seized and plastic parts melted. The anti rotation bracket had come off too, but didn't stop the release lever from working. The clutch fingers are scored a little, but might get away without replacing. I'll have a better look tomorrow and have the clutch off to ensure it's ok.
DaveB

 

[Mike Pass]

That looks a bit nasty. I would go for the upgraded release bearing and carrier setup. Chris Cole or Mick Sollis etc. do them. I have one on my car. The all metal one and better bearing is so much better than the plastic Renault original. Whilst you might get away with the scored fingers I would get a new one fitted now while the thing is apart and then you can be confident that all is well when it goes back together.
Cheers
Mike

 

[Brian Magee]

Hi Dave,

So that was you on the motorway around Glasgow on Friday 9th. I was concentrating on the traffic ahead when my wife said she saw a red GT40 going the other way. I guessed it must have been you.

We have just returned from three weeks in Scotland in the motorhome. We spent three days on Orkney and on the way down we did Fort William to Malaig and back on the Hogwort's Express steam train. Wonderful scenery and brilliant coastal walks.

Brian.

 

[Frank Catt]

Dave, there are several versions available as Mike said, but you will also need to reset / replace the spigot bearing and carrier because the witness marks suggest an insufficient support.

 

[Dave Bilyk]

Frank, the spigot bearing is just a bronze bush pressed into the crank end. It will almost certainly have some wear now so I will check the size when I remove the clutch. Is that standard or are roller bearings the common choice these days?

Brian, yes on Friday 9th in the morning around 11am by my recollection, your wife would probably have noticed the number 83. Glad you enjoyed, Scotland is a great place to tour.

Mike, nasty yes, but at least it didn't stop me, and I found it was reasonably easy to change gear without the clutch. Actually, I was delighted that the engine performed as it was the first time I pushed the car with the new camshaft and roller rockers. Your advice is clearly good, I will get into it after holiday so it with be late june before I get serious with it.

Dave

 

[Frank Catt]

Dave, go roller bearings in a custom made holder, but measure your clearances very carefully, I can send you a " how to do it" if wanted, Frank

 

[Dave Bilyk]

I took the clutch off just now, pressure surfaces and plate are fine, just needs a little debris cleaning out from the inside surface of the pressure plate housing. The input shaft spigot dia is 0.6675" or 16.955mm, the bush is .6913" or 17.56mm so about 0.6mm clearance, so I intend to change to a bearing.
DaveB

 

[Dave Bilyk]

An update; I got new pintle and release bearings from Chris Cole.
The big job was removing the old bronze bush from the crankshaft end. This was pressed in with interference on two diameters and was a pig to remove. The hole diameter was about 17.6mm which is good for a 20mm tap, so I borrowed a tap and a 20mm bolt, and got to work.

Not too easy tapping 20mm by hand even in bronze btw, but then extracting the bush by screwing in the bolt took a couple of hours of hard sweat and toil, and I had to spread that over two nights, turning a bit at a time due to limited space, and bending of 1/2 drive bars! I wasn't prepared to hammer it in case I flattened the main bearing babbit.

Assembled the bearing into the carrier by putting the bearing in the freezer, and the carrier in boiling water, then heated the flywheel area with my space heater, with the assembled bearing/carrier in the freezer.

One issue was that the pintle bearing would only engage part of the input shaft end, so I packed it out about 3mm with washers, which was as much as I felt comfortable with while maintaining enough engagement in the interference length in the crank.