Macleod RST noise

FarnhamStag · Post by **FarnhamStag** » Sun May 17, 2015 9:36 am

I've just fitted a Macleod twin plate RST clutch and flywheel to a 4.2 rover V8 sourced from Real Steel mated to a R380 2wd box using standard Rover SD1 plastic release bearing and pivot arm and slave cylinder.
I have two problems, the clutch appears to work correctly (although I haven't put much power through it yet)

1. There is a strange rattle at idle, that comes and goes..it includes a slight rubbing noise occasionally too.
2. It only disengages with the clutch pedal on the floor and I suspect its dragging. The master cylinder is a larger bore than the SD1 so I should be get the same or longer stroke.

Reading the forum people have had problems with the release bearing needing machining to avoid it resting on the clutch fingers. If this were the case surely it would disengage higher in the pedal travel?

A garage did the change for me,it was a lot of work since (circa 20hours) much easier with ramps but it costs so removing the gearbox for inspection is the last resort..

Do the twin plates usually rattle at idle?
Any ideas about the long throw on the pedal?
How can I diagnose without removing it?

Thanks

SuperV8 · Post by **SuperV8** » Mon May 18, 2015 8:36 am

Rattle at idle/neutral is usually the damper springs in the friction plate. Does the rattle go away when you put your foot on the clutch?

Air in the system could mean the clutch won't disengage fully or drag.

Tom.

DaveEFI · Post by **DaveEFI** » Mon May 18, 2015 9:45 am

Remember the actual gearbox on my P6 3500S used to chatter if the idle speed was too low.

FarnhamStag · Post by **FarnhamStag** » Mon May 18, 2015 1:55 pm

Thanks
The Rattle does seem to go with my foot on the clutch but it doesn't disengage until my foots floored..I'll check for air in the system but it I doubt there is any in there...
The gearbox does sometimes rattle on Idle but this is definitely from the clutch.

I'll take a look at the slave tonight..I just want to avoid completing the car assembly only then have to take it all apart again!

Thanks Dorian

DEVONMAN · Post by **DEVONMAN** » Mon May 18, 2015 4:04 pm

Sometimes the slave cylinder has a very light spring behind the piston to keep the thrust bearing in contact with the fingers thereby preventing rattle and loss of initial clutch movement. Check yours.

Also if the floater plate has not been set up properly to move away slightly from the front plate as the clutch is released then the clutch may not clear fully.
However as the plates wear in things should improve.

Regards Denis

stevieturbo · Post by **stevieturbo** » Mon May 18, 2015 10:47 pm

Typed a reply earlier then it went AWOL.

In brief

A twin plate will never rattle when your foot is off the clutch pedal.

Some twin plates can rattle when the pedal is depressed ( engine running of course )

The noise you describe does sound release bearing related.

If you cannot see in there to see if anything is loose or moving, buy a cheap bore scope camera for the laptop, eg

http://www.ebay.co.uk/itm/USB-Waterproo ... 2edf84d592

Then you can shove this into the bellhousing, drilling a small hole if required. Obviously taking care not to catch it on anything if the engine is running at the time

FarnhamStag · Post by **FarnhamStag** » Tue May 19, 2015 11:32 am

Thanks, the camera idea sounds sensible so I'll give that a go before anything else!

Unfortunately that won't be for around 10 days so I'll update the thread then.

Dorian

FarnhamStag · Post by **FarnhamStag** » Sat May 30, 2015 6:59 pm

I had time to take a closer look today and tried the bore scope camera idea so thanks for that. I'm 99% sure there's around 10mm or more free space behind the release bearing and the back of the gearbox so I don't think the release bearing is being held against the clutch.

The noise is more of a rubbing/ scraping noise and isn't always there, sometimes its without the clutch being depressed and pushing the clutch in silences the noise, and other times it starts when the clutch pressed and was silent before, repeated pressing can cancel the noise, very strange.

I used a flat faces release bearing, the RST clutch had a raised section on its fingers, is that the right type to use?

The only other doubt is that the flywheel did say that some rover engines may need a small amount of webbing removed to clear the flywheel..not sure how carefully the fitters looked at that...

I guess that since the noise can happen with both the clutch pressed and not pressed I may have to just drive it and see if it goes away or gets worse unless anyone else has any other ideas?

Thanks, Dorian

stevieturbo · Post by **stevieturbo** » Sat May 30, 2015 7:06 pm

Dont think the release bearing should be too fussy, and not the cause of noise.

I know when I fitted the street twin to my LT77, the bellhousing needed clearanced. No idea if your setup would require similar.

I dont think my engine would have turned over interference was too much though if I didnt clearance the bellhousing.

Maybe that aspect is worth a peek with the camera ?

Dont recall any issues on the engine side of the flywheel

Denis247 · Post by **Denis247** » Sun May 31, 2015 7:41 pm

Could it be very slight rubbing on the block webbing, the crank end-float being the reason that sometimes it's there and at others it isn't?

FarnhamStag · Post by **FarnhamStag** » Wed Jun 03, 2015 12:32 pm

I came to the same conclusion and I'm hoping that eventually it might wear away the aluminium where it fouls, but it rarely works out that easily!

Anyway for now I'm putting the rest of the car back together which should allow a few miles of testing at the weekend.

Thanks for all the advice,

Dorian