Clutch - Again!

[Steve in Dublin]

Ok I know we have been around this house before....

 

I have a 1973 CR. I replaced the original slipping clutch with a Borg & Beck kit. A bit later into the car's life the engine was rebuilt. Soon after the clutch pipe, the rubber one between master and slave developed a leak. This I replaced with a braided one. Around this time or shortly after, the clutch developed a 'chatter' where especially if cold and fully disengaged you could clearly hear a rattle off the clutch which would dissapear as soon as the clutch was slightly engaged. It wouldn't happen all of the time either,

 

So out came the box and in went a Koyo bearing, bronze carrier, new fork, new (old stock) Laycock cover, new plate and uprated tapered pin. After a few hundred miles came the dreaded 'sticky clutch' as clearly outlined in this article on Buckeye Triumphs.

 

The gearbox has a small leak and soon, out will come the box to repair it. So my questions are pretty simple - What is the best clutch to install? And any recomendations as to method or pitfalls I should be aware of or what to be checking. I know the gearbox takes alot of concentration to put it back. Is the Koyo bearing best or is the current replacement bearings suitable or perhaps other alternatives such as Gunst. On a simple level, could the stickyness just be down to the braided pipe replacement? If the Koyo bearing is fine, is there a modification that may not have been done that could be causing the stickeyness?

 

Thanks for any help, suggestions and ideas here

 

[stuart]

Did you fit the dowel bolts to correctly line up the gearbox when fitting it?

Stuart.

[RobinTR6]

I had the dreaded sticky clutch, replaced the bearing , taper and cross shaft. All those seemed OK but replaced anyway. I did double up on the cross shaft bearings for a few extra pence and I am sure this had some beneficial effect, in any event the sticky clutch went away never to return.

 

There seems to be quite a few views on the bearing, think mine was a Koyo

 

Good luck Robin

[Steve in Dublin]

As far as I am aware the gearbox was set up using dowels. It has to come out again anyway and I will ensure that they are used in putting the box back.

[TR NIALL]

Steve,when replacing the Bearing are you using any type of Lubricant or just putting Bearing on Dry,if using a Lubricant what type have you used.

[TRTOM2498PI]

Hi Steve,

 

I have an early TR6, and had what I believe is known as a 'ratchet' clutch. Once engine was up to operating temperature, releasing the clutch slowly and smoothly was difficult, upon release of the clutch pedal, it would be very jerky.

 

It transpired that the nose piece inside the gearbox was slightly bent / warped, which didnt allow the bearing carrier to slide up and down freely and smoothly. As a precaution I had the cross shaft, with extra support on either side with uprated bushes, and new nose piece installed - all new items. This resolved the issue.

 

I am not saying this is your issue, but I had the same issue some years ago, and this resolved the issue.

 

I also use a Laycock 3 piece clutch. Difficult to obtain these days, but you may be lucky.

 

 

Good luck.

 

 

Cheers

[Steve in Dublin]

Niall - It would have been greased, but what I suspect is that is happening is that over time either the grease moves off the nose and or bearing and gets full of **** or as it gets heated becomes ineffective. This then comes to Tom's point - I suspect the bearing clips the end of the nose as the lubricant becomes ineffective thus causing both scrappings that gets into the lubricant and marks\scars the gearbox nose.

 

Thanks for the tips. I can see I am going to need a new cross shaft, nose and bushes at least as well as some high temperture bearing grease as suggested by Buckeye. Hopefully some of the parts more recently replaced are still good! Then make sure its all carefully put back together and aligned properly using the dowels...Anything I've missed?

 

[AndrewP]

Well worth following the advise given to me by SimonjrWinter. He suggested that the carrier be polished and the leading and trailing edges chamfered. Did this on my bronze carrier, kept trial fitting until I got an acceptable sleave to nose clearance and then a very small amount of hitemp grease. I used the B&B kit and so far so good (500+ miles) with a smooth and judder free clutch. I used the dowel bolts as recommended by all to ensure good alignment.

 

Andrew

[15eren]

Hi

I have just had the box out to repair the sticky clutch. Have done excactly like Andrew, that is smoothing the edges, polishing the new nose and the new bronce sleeve and only adding a small amount of high-temp grease. And of course new pin-bolts and extra securing of the fork and using the speciel size of dowel bolts to insure correct alignment of engine and gearbox.

And the result is a perfect clutch so far. I have only driven few miles till now, but I am quite sure that it will last.

 

Tage

[Steve in Dublin]

Thanks again for the replies.

I will ensure all edges are smoothed off and the sleeve\nose polished - what would you suggest I polish with?

[TR NIALL]

Steve,when Polishing or smoothing off Edges use Fine Emery Cloth/Paper.Have you anyway of Testing to see if the Shaft is bent, if not Talk to Martin he maybe able to help.

Edited November 16, 2011 by TR NIALL

[Guest ntc]

When you have finished, NO gease just a light smear of copperslip on the nose and the face of the bearing

[TR NIALL]

When you have finished, NO gease just a light smear of copperslip on the nose and the face of the bearing

 

The above would be my prefered method also,the Lubricating of everything is not needed and can lead to other problems.

[Steve in Dublin]

Thanks for the tips on polishing - I will ensure they are done with light emery. And a only light smearing of Copaslip on the nose and bearing face.

 

I think to be sure I am going to follow the advice earlier in the thread and replace the crosshaft and its bearings etc - as is, its still the original with 80 or 90,000 miles on it. I will also replace the nose too

 

The plan is coming together nicely

 

[Davidw]

Not wishing to hijack this thread but I notice no-onw has commented about the Tilton Coaxial clutch system much beloved of Roger Williams in the How to book?

[Alec Pringle]

Hi David,

 

probably because it's more relevant to competition cars than the average road car. Not many of us are going to lash out a grand on a Tilton clutch assembly without a good reason for doing so.

 

There is nothing wrong with the original system for road use, regardless of whether it's Laycock or Borg & Beck type - any of the decent clutch manufacturer's products can and will do a perfectly good job, and the same goes for the products of the handful of high quality clutch reconditioning companies. That does not include el cheapo repro clutch components, nor el cheapo reconditioners, need I add.

 

The usual problem with clutch installations is the bloke doing the job, whether he's an amateur or a professional.

 

Cheers,

 

Alec

[Davidw]

Hi David,

 

probably because it's more relevant to competition cars than the average road car. Not many of us are going to lash out a grand on a Tilton clutch assembly without a good reason for doing so.

 

There is nothing wrong with the original system for road use, regardless of whether it's Laycock or Borg & Beck type - any of the decent clutch manufacturer's products can and will do a perfectly good job, and the same goes for the products of the handful of high quality clutch reconditioning companies. That does not include el cheapo repro clutch components, nor el cheapo reconditioners, need I add.

 

The usual problem with clutch installations is the bloke doing the job, whether he's an amateur or a professional.

 

Cheers,

 

Alec

 

 

Thanks for clearing that up for me, Alec. I was considering getting such a system when the time comes because of so many horror stories about the original system. Having said which I had replaced the clutch twice on my prev. 6 (second time when the box failed) with no problems, so presumably the answer is get the components from a reputable supplier ad avoid suspiciously cheap ones?

[stuart]

Having said which I had replaced the clutch twice on my prev. 6 (second time when the box failed) with no problems, so presumably the answer is get the components from a reputable supplier ad avoid suspiciously cheap ones?

 

And setting them up properly.

Stuart.

[TR NIALL]

Having seen Steves Clutch and Bearing Today i was not too impressed with what i seen,hopefully he will post pictures for all to see and maybe we can all learn that Uprated dont always work.

[Steve in Dublin]

As Niall has implied above, the gearbox and clutch are now out of the car.

 

First thing to note was the slave was mounted to the wrong side of it's bracket. This can be done in order to accommodate a spin on oil filter, as in my case and\or is used as a fix for wear in other parts of the clutch system. I will be ensuring the oil filter angle is adjusted and the push rod in the slave not cut down...

 

I had a Koyo bearing, originally designed for a Land Cruiser and a Laycock cover. This was put in less than 1500miles\2500km ago, earlier this year. Problems first started to occur after about 500 miles and would happen when the car had well and truly warmed up after say 50 miles or so. Driving into my garage storage area could be quite challenging after a day out, as well as onto the ferry on the way back from Harrogate! These seem to be the 'usual' symptoms of 'Sticky Clutch'

 

 

In the above picture is the Koyo bearing on the left which is much deeper and chunkier than the RHP bearing on the right

 

 

In the above picture you can see the two bearings. The Koyo is on the left. You can see the Koyo has a deeper bevelled opening 'mouth' compared to the RHP.

 

 

In this picture you can see to the wear caused by the Koyo bearing to the fingers\springs. The fingers on the Laycock plate level off at a steady, shallow and tapered angle in toward the centre of the plate and the tips end up inside the mouth of the bearing before contact is made. This reduces the leverage effect of the fingers. No doubt this causes heat build up too - hence the time for sticky clutch to happen. On offering up the RHP bearing up to the Laycock plate it marries properly the tip of the springs to give maximum leverage.

 

So we will be putting the RHP bearing in. We will be using a Borg and Beck plate as the Laycock one here is finished.

 

Our conclusion is if you want to use the Koyo do not use a Laycock plate. On offering up the Koyo to the Borg & Beck plate it does marry ok. That is because the fingers taper away steadily at first but the for the last 3/4" or so the angle toward the centre becomes steeper and leaves a level 1/2" at the end finger which the Koyo can meet and therefore none goes in the mouth of the bearing. (If that makes sense and hard to show in picture!).

 

I have very minimal mechanical skill but I hope I have made myself clear enough.

 

Edited November 21, 2011 by Steve in Dublin

[Steve in Dublin]

I have been asked to put up a couple more pictures - especially the Borg & Beck plate

 

 

The picture above is the Borg & Beck plate. There is some slight wear on the top of fingers but is usable. You should note that my car has never used the Borg & Beck - Koyo bearing set up and the lighter circular marks on the fingers are part of the design.

 

 

This is the Borg & Beck from the side. You can see the fingers taper at a steady angle inwards and then sharply rise to form a small plateau - which if you decide to use a Koyo bearing sits inside the bearing mouth and (probably) connects with the bearing on the taper side correctly.

 

 

This is the Laycock from the side. You can see the fingers taper a steady angle all the way to the middle and there is no plateau. If you use the Koyo with this, the fingers eventually connect to the bearing and causes the heavy wear you can see in both this and the earlier picture. Costly

 

 

Edited November 20, 2011 by Steve in Dublin

[Alec Pringle]

Hi Steve,

 

excellent illustrations of the problem, well done.

 

The Laycock components can probably be reconditioned with a replacement spring diaphragm - both covers and friction plates can be reconditioned to OE standard or better, assuming the basic metal frame, as it were, is OK. Niall has my contact details if you'd like that organising.

 

Cheers,

 

Alec

[TR NIALL]

Hi Steve,

 

excellent illustrations of the problem, well done.

 

The Laycock components can probably be reconditioned with a replacement spring diaphragm - both covers and friction plates can be reconditioned to OE standard or better, assuming the basic metal frame, as it were, is OK. Niall has my contact details if you'd like that organising.

 

Cheers,

 

Alec

 

As Steve is off to Live in a Warmer Climate in the New Year we are trying to make his Car as reliable as poss before he leaves.The Pressure Plate will be Traveling with me to Malvern as Ballast or maybe for a Recon,if of no use it can Swim with the Fishes in the Irish Sea.

[TR NIALL]

The Ending to this Saga is Do Not Use the Toyo Bearing with a Laycock Pressure Plate.

[Steve in Dublin]

Just to give you an update. We put in the Borg & Beck plate with the RHP bearing as in the pictures. OK the clutch is stiffer compared to the Koyo\Laycock set up but hey I need to lose a few punds anyway. I have done 50 miles so far in all sorts of driving conditions - motorway through to heavy duty traffic the car fully warmed up NO STICKY CLUTCH or rattle. The big test comes as I have a 1300km drive in the next few weeks although I feel confident with this set up.