clutch noise

[nigethomas]

Hi

 

I tried my gearbox today for first time.

I fitted new clutch and bearing etc.also

New slave cylinder and master cylinder.when first fired the engine up it went into all the gears fine.then suddenly every time I engage the clutch I get loud screeching noise.once clutch is released noise goes.is this something to do with the release bearing carrier?

 

Nige

[Lebro]

Sounds like something is not right with the release mechanism somewhere, you may have no choice but to pull it apart again

 

Bob.

[Geko]

if you engage the clutch halfway through is it the same noise as fully depressed? If not you might have a wrong carrier indeed.

Edited July 2, 2016 by Geko

[nigethomas]

Yep still the same noise.think I need to replace the steel carrier with a bronze one.should of done this from the start.am I right in saying there is no roll pin fitted on the bronze carrier to secure it to the fork?also will I need to replace release bearing again?

 

Nige

[RogerH]

Hi Nige,

I have never had any luck with the steel carrier. The bronze ones always work(sort of).

The TR4 carrier is different to what is required on the 4A. The Moss cat does not show a brass carrier for the 4A but it does exist within their caverns.

Ask the man to put an X after the part number.

 

There is no need for a stop pin as the brass is self lubricating and is happy to spin - if need be.

 

One problem I have found on my last three carriers is that for whatever reason the carrier did not spin and eventually the pegs on the fork dug into the carrier quite deeply. This had two effects - 1, this stopped the carrier rotating if it wanted to. 2, pedal travel was slowly reduced.

 

I believe Chris Wittor does a kit to replace the fork pegs with flat faced slipper pads.

 

 

Roger

[nigethomas]

OK thanks Roger.on the release bearing the outside spins with the clutch but inside is fixed is this correct?

 

Nige

[RogerH]

Hi Nige,

the inner diameter of the release bearing is permanently fixed to the carrier.

The front face of the release bearing rotates when in contact with the diaphragm fingers.

 

On the TR4 the bearing is pulled back away form the fingers when not in use. So the release bearing only rotates when being operated.

On the TR4A I under stand that the release bearing could be in contact with the fingers all the time so could be rotating all the time - no return spring

 

For the TR4 the release bearing needs to spin up to speed very quickly so as not to wear the fingers.

Thus the centre race needs to be very free to spin - they never are free so the fingers will wear - but on the TR4 the fingers are big.

 

On the TR4A the bearing could/should be spinning all the time so the fingers are saved but the bearing will clap out one day.

 

Can somebody substantiate the above - or am I talking out of my rear orifice again.

 

Roger

[Lebro]

Sounds spot on to me Roger, though I never quite understood why the carrier can also rotate.

Would it not be better locked to the forks in some way ?

 

Bob.

[nigethomas]

OK Roger yes it all makes sense.it does seem bad idea to have bearing spinning all time.regards to the return spring I have one fitted at present.think I've read people's views on this being fitted before and some were for and against it.anyway looks like box is coming out next weekend

And new bronze carrier fitted.hopefully should sort it cheers

 

Nige

[nigethomas]

Well managed to remove the gearbox last night as wanted a head start for the weekend.

I noticed that the release bearing was seized solid and not spinning.This must have been

caused by the stress on it due to the steel carrier spinning.Have ordered new bearing

and bronze carrier.

 

Nige

[RogerH]

Hi Nige,

the release bearing is set solid on the carrier - only its inner race (front face) rotates. This can be quite stiff (and it shouldn't be).

 

If the inner race has seized has it done any damage to the fingers of the diaphragm.

 

Roger

[nigethomas]

Hi Roger

 

Yes it looks like the inner race has seized as well.It was a new clutch and release bearing fitted.

i checked the fingers and they seemed ok not bent or anything.There are signs of blueing on them

but that is to be expected.I only tried the gearbox for short period just to see if all the gears went in

which they did but just had that high pitch noise.

 

Nige

[RogerH]

Hi Nige,

what release bearing did you use. Moss do a nice RHP that I've found OK - a couple of bob more than the cheapo but it works.

 

Roger

[nigethomas]

I ordered the clutch kit from dave kingerley and it came with the bearing.

ive ordered a new bearing from moss this morning GRB211 and another

tapered pin.Did seem odd for the bearing to seize up like that though.Ive

never come across that before even when replaced clutches on high mileage

vehicles

 

Cheers

 

Nige

[nigethomas]

Hi Roger

 

My parts arrived today.the new bronze carrier has come with the roll pin already located in it.I take it this has to be removed before fitting?I have spoken

to the suppler and they said that the pin needs to stay in there ?

 

Cheers

Nige

Edited July 7, 2016 by nigethomas

[RogerH]

Hi Nige,

the bronze carrier should be able to rotate (as far as I understand). It is self lubricating so that will not be a problem,

 

If the carrier stays in the same place you may well find that the round lugs on the fork will dig in - this will definitely lock the carrier from rotating.

I understand that Chris Wittor does an improved fork attachment using pads rather than round spigots.

 

The GRB211 bearing is the basic bearing from Moss - I'm sure they do a good quality RHP for about twice that price.

 

Roger

Edited July 7, 2016 by RogerH

[nigethomas]

Hi Roger

 

There seems to be different opinions on the bronze carrier having the pin fitted or without.

I have read an article on the internet by moss explaining about this carrier and that the

pin should be left out.You would think that the fork would wear this way though if spinning

constant.I dont really want the fork digging in to the carrier though if pin is left in.Think i

will just remove it and put box back in.Does anybody else have any opinions on this

within the forum?

 

Cheers

 

Nige

[stuart]

I take the pin out. Better for the wear to be even.

Stuart.

[nigethomas]

Hi stuart

 

I think your right will go with that

 

Nige

[nigethomas]

Well took my 4a for its first drive yesterday just down the road.I hadn't even got off the drive and smoke was coming from the bell housing.same screeching noise.once came back again.checked adjustment again on slave cylinder and was going back ok once fully pressed.I've no idea why clutch is sticking on.all clutch kit is new and fitted brass carrier minus pin.it sounds awfull now when putting into gear.not sure where to go with this I've done everything as should be.

 

Nige

[RogerH]

Hi NIge,

I sympathise completely with you. If tears would help then I'll post a you a few.

 

Could the screeching cause by flywheel attachment bolts being too long. The ends then bash on the lower front GB cover plate.

Have you checked your crank for end float - this may allow things to contact where they shouldn't.

Smoke there shouldn't be any smoke. Could simply be heated oil in the bell housing.

 

I had my GB out two weeks ago because the clutch was becoming sticky on the return - very bad towards the end.

With all new parts inside the bellhousing (everything) I was expecting success.

All went well until last Saturday (that rebuild lasted all of three days). The clutch return was as bad as ever.

 

The actual pressure required on the pedal is very low. It has never been easier; but once the system gets hot it sticks.

 

I have the GB out at the moment to see if there were any telltale signs - nothing.

 

I'm using a fancy new steel carrier but without the anti-rotation pin. I think I'll put it back but with the pin this time.

 

I found that the recent carier was 0.005" small in ID than the old good one that was in there last year.

Sadly the new steel carrier is the same as the old good one.

 

I noted that there was some lacquer on the input shaft extension nose - I've now removed this.

 

I fear that I will reinstall the GB and there will be no improvement.

 

Don't despair

 

Just had a thought. Have you had the flywheel off. If you did, did you reinstall the bronze bush in the back of the crank.

If this is not insitu then the input shaft will thrash about and hit the diaphragm fingers - I bet that could screech.

 

Roger

[Guest ntc]

Are you fitting it all dry?

[RogerH]

Hi Nige,

apart from the lacquer on the extension nose and the lack of the anti-rotation pin in the carrier I have found that the input drive shaft is not co-axial with the extension nose - it is greater than 0.015" adrift.

I don;t know if this would make the clutch stick with the engine rotating but it is something to be hopeful for.

 

I have also installed a pipe that could supply either cleaning fluid or oil to the carrier/extension nose. I'll stick a pic on later.

It is just for diagnosis more than anything else.

 

Roger

 

PS - the carrier was fitted dry

Edited July 31, 2016 by RogerH

[nigethomas]

Hi Roger

 

I had to sink a few beers last night to de stress.the thought of having to pull box out again and most likely have to replace all components.the smoke is definitely clutch plate burning smell not oil.it's almost as though the clutch is in constant mesh with flywheel.it goes into gear ok though no crunching etc.think you mean the spigot bush that sits behind flywheel yeah that was definitely in position.think problem with mine and possibly yours is the bearing carrier and what set up is best.something somewhere is jamming on and causing problems with release bearing.i felt like calling it day yesterday so bloody frustrating.you seem to go round in circles with restoration work.on a positive note my engine is running well ????

[RogerH]

Hi Nige,

I have spent the last couple of hours making a tool to measure the alignment of the input shaft and the extension nose.

Mine is definitely +0.015" adrift - will this make a difference ?

I have removed my diagnostic oiling pipe (bad idea)

 

Tomorrow I am going to machine a slight taper on the back of the bearing carrier to allow any 'cocking' to be absorbed.

It will taper just a degree or so down to about half the length of the carrier.

 

For my problem I think any non-coaxial misalignment is coming into play when the clutch is rotating.

When you push it in with the pedal, the fork pushes the centreline of the carrier and so it goes in nicely.

When coming out the diaphragm fingers are pushing the bearing but as the bearing has a curved face the misalignment is cocking the carrier and digging it into the extension - or maybe not.

 

Roger