K clutch release bearing

[Nick Green]

The clutch release bearing on my 99 K series 6-speed car (with a dry sump, if that is relevant) is showing signs of giving up the ghost.

 

Does anyone know of an equivalent (manufacturer, part no.) to the Caterham-supplied item that might prove more durable ? Perhaps with an all-metal construction ? I have been given some leads to chase, but I'm wondering if someone has already been there...

 

I know Caterham have done a mod to the input shaft sleeve to stop bearings being destroyed, but I don't know for sure if I have this on my car's gearbox. Informed sources say "yes", but I won't believe it till I see it.

 

Thanks in advance, Nick.

[Brad Tipp]

Nick,

Mine gave up the ghost recently at 6500 miles. I didn't know there was a mod for the input shaft sleeve!! How can I tell if mine has/hasn't got it?

 

 

T 1 PPB - Superlight

 

"Well yes officer i'm not arguing, it's just that [insert excuse here]..."

[Nick Green]

Brad, if you have the modification, the input shaft sleeve should have a steel piece on the end. The standard shaft sleeve is clearly one metal along its whole length.

 

I'm afraid I can't tell you any more than that, as I don't think I've seen it yet! Engine and gearbox are to be pulled... I am ringing around trying to find a source of a beefier CRB, just to be on the safe side. No luck yet, though Caterham assure me I won't have the problem again, if I convert to the new input shaft sleeve. Of course if it turns out I already have it...

 

I have already talked with AP, who supply the clutch in my car to Caterham, but the drawings I have been faxed of the CRBs they do, which would match the clutch cover, do not match the Caterham-supplied CRB... Ho hum.

[Brad Tipp]

Great, so I had mine changed already and didn't look at the shaft!! I'll ring Caterham and see if they can tell me from the build number of my car if have the mod or not.

How many miles had you done?

Do let me know if you find a better version as I'll put it in next time :-(

 

Ho hum, out with the engine again by the sound of it.

 

T 1 PPB - Superlight

 

"Well yes officer i'm not arguing, it's just that [insert excuse here]..."

[V7 SLR]

OK, from the bits I've seen, the problem is that the release bearing inner circumference is bigger than the out circ of the gearbox shaft. This, coupled to the fact that the clutch fork tries to push the bearing so that is is at an angle on the shaft (when viewed from the side) leads to breakage.

 

Also, the gearbox shaft may be too short. I'm not 100% sure about that.

 

Anyway, the gearbox mod is a piece of ali that fits over the existing shaft, kinda like a condom. This adds both width and length to the shaft, and means the bearing fits more snugly, and won't fall off the end.

 

There are uprated bearings, or at least were but I'm not sure who was making them, nor their part number. I have heard of a number of people chasing them down, with little success. They were sintered metal in construction, instead of the plastic carrier currently used.

 

I know of at least one person who has had the gearbox shaft mod done, but using standard bearings still finds they are destroyed fairly quickly. Then again, I've not got the mod on my SLR and I'm still on the same standard bearing that I put in during the build, 13,500 miles ago. I don't get any bearing noise at all, but that's probably put the kiss of death on it now hasn't it...?

 

Edited by - V7 SLR on 29 Aug 2001 16:32:04

[Nick Green]

If you didn't know to look, you wouldn't would you ? sad.gif

 

As your car is a T plate (T1PPB), then unless someone has changed it, you probably have the old shaft sleeve. IIRC, the mod came in during '99. I didn't have the wit to verify what I had on the gearbox supplied to me.

 

I've done just over 10k on this CRB.

 

I'll post if I find anything useful.

 

Alternatively, if anyone else is reading this, can anyone vouch first hand that the modified shaft sleeve and caterham-supplied CRB will do substantially more than 10k miles ??

[Nick Green]

Was concocting my last reply while V7's was arriving...

 

That last para cheers me up no end. Phil Stewart at Road and Race Transmissions, said there was also a duff batch of bearings about that time.

 

I'll keep phoning, but as V7 says, I can't say I hold out a lot of hope.

[CHRIS CLARK]

Nigel.

 

That piece of aluminium that fits like a sleeve over the existing shaft is actually STEEL. The problem was that the boxes that had this section as a one piece ali section would wear them. As the bearing moved for & aft it created ridges in it. The new steel sleeve mod. is supposed to eliminate this. Cost with an oil seal and the cork gasket is around the fifty quid mark.

 

The sleeve also appears to be fractionally larger in diameter than the old one too!

[Rob Walker]

I hate to say that the gearbox input shaft mod hasn`t stopped my car eating release bearings. I have had two fall to bits so far in less tah 10K miles.