Clutch problem

[steamy]

I am hoping the experts among you can help with the diagnosis:

My 1967 TR4A has developed a 'sticky' non smooth clutch pedal operation. When cold it is smooth on depressing pedal but 'sticky' or juddery on release. When hot it gets worse to the extent the pedal gets harder to operate as it gets hotter and although when driving not that noticeable but when starting off say from a junction etc the pedal comes up in 'notches' and very difficult to control take off. The slave cylinder was replaced 600 miles ago together with service kit on master cylinder. Not sure which direction to go....hydraulics....gearbox...clutch release bearing etc?

Any advice appreciated.

 

Ian

 

[RogerH]

Hi Ian,

almost certainly it is the clutch release bearing extension - item #60 http://www.moss-europe.co.uk/shop-by-model/triumph/tr2-4a/clutch-transmission-drivetrain/gearboxes-components/gearboxes-external-components-tr2-4a.html

 

Remove the gearbox and before cleaning anything look closely at everything that has a clean wear pattern/mark on it.

Ensure that the two alignment dowels are present on the engine/gearbox attachment flange.

 

Remove the clutch fork and release bearing.

Look around the steel tube of the extension and look for any wear - I had very subtle marks in the 6-o-clock position - almost invisible.

 

If you can, see how concentric the extension is (#60) with the gearbox input splined shaft. Mine was out verticlaly by 0.015" AND that made the difference. Everything must be in alignment.

 

If you need to replace the bearing carrier and you want a Bronze one go to Revington - all the others use a soft brass jobby.

I have found that the TRShop steel carrier works perfectly well.

Use a quality RHP release bearing £50 or so.

 

Look at the fingers of the pressure plate. Is the wear pattern even

 

Roger

[Richardtr3a]

I have just read an article on Buckeye triumph site. They found that the sleeve and the bearing carrier would stick if the leading edges were not file to a round profile instead of a sharp edge,

 

This may be your problem.

 

Richard & H.

[RogerH]

Hi Richard,

In thought of that possibility when having my Clutching and machined radii on the edges. It nearly worked. The judder/Ratchet clutch came back.

 

The buckeye article also suggested that things were out of alignment and causing the carrier to foul up on the extension.

 

Establish that the extension and splined shaft are in perfect alignment.

 

I machined up a ring that had the OD of the extension and an ID of the splined shaft. Put the ring overe the spline and see if the extension agree's.

 

Roger

[steamy]

Hi Roger,

Many thanks for the very full answer....I think I was expecting a box out job..bother!

Could this situation get worse and terminal or can I carry on and do the job during the winter?

"we might even get an Indian summer"

 

Many thanks

Ian

[steamy]

Thanks again Richard and Roger....I will inspect when I strip down and machine up an alignment sleeve,that makes sense.

 

Ian

[RogerH]

Hi Ian,

if it is the bearing carrier digging onto the extension then it will get worse and become quite difficult to drive (kangaroo'ing).

 

If it is possible to get some oil/grease onto the extension then that will help - but it is difficult to get to.

 

 

Roger

[steamy]

OK Roger, thanks

 

Ian

[steamy]

Update........took car for a spin today.........started out with expected clutch problem that had been getting worse over a 4 week period and after about 20 minutes........bingo........PROBLEM GONE!! Now got a lovely smooth operating clutch. Question----why, how etc. Was it possible for some dirt or grit got onto the sleeve and been dislodged?

I like your idea Roger of trying to get some grease or lubrication in that area and my thoughts are maybe a spray silicon lubricant through where the bottom cover goes.

Any advice whether to try this or leave well alone while all seems OK?

 

Thanks

Ian

[RogerH]

Hi Ian,

if it is working leave well alone.

I don;t think you will get access from the plate at the bottom of the bell housing.

 

Worry about lubrication if you need it.

 

Roger

[steamy]

I am sure you are right Roger..If it aint broke don't fix it!

 

Thanks for advice and lets hope it stays fixed

 

Ian