Clutch Release Bearing Noise

[SuperRedMR2]

Hi,

I didn't think i'd have this problem over anything else so soon!

I replaced the clutch release bearing as I left my g'box out to the elements and it went rusty. Replaced the bearing with a Koyo bearing brand new.

Greased up the shaft, didn't the replace clutch as it had only covered 1350 miles and was in great condition.

As of Saturday sitting in traffic, a noise occurred in neutral and went away when i depressed the clutch.

I have contacted the supplier who said if it was the bearing it would make a noise when the clutch is depressed and not when it's out of gear. But I thought when it's depressed it's under pressure from the clutch therefore when its free it can rattle around and make a noise? I have covered 111 miles since it's return to the road.

It's not causing any clutch issues (yet) but considering all the time and effort and money I've spent doing this, the g'box will have to come off again to replace the part sooner or later.

Any other ideas?

[PW@Woodsport]

Given the symptoms, a fair guess would be gearbox input shaft bearing, nearly all of the C50/52 gearboxes I strip down have knackered input shaft bearings, which will go silent when you press the clutch down (input shaft stops turning).

Bad news is it's a full gearbox strip and rebuild to replace it, the bearing itself is about £50. The best option is just to change the gearbox, although finding a low mileage one is the next problem.

[SuperRedMR2]

Hi Paul,

The box has to come off anyway like you said so I'll source another one - unlikely to be the release bearing then yeah?

[SonicSW20]

Input shaft bearing is a likely cause as Paul said, I've come across it a few times on the S54 (mk2 NA) box as well. My old one was noisy for 4 years / 60k miles, didn't seem to get any worse / affect the car.

[SuperRedMR2]

It's just a massive annoyance as I've spent time and effort getting it all running well, now the box has to come off again. Sods law!

Has anyone got a part number for the shaft just out of curiosity

cheers

[PW@Woodsport]

Bear in mind this is just an internet diagnosis, nothing more than my best guess, I don't want someone changing a gearbox on a guess..... it's just as possible your release bearing has an issue.

Part number for the input shaft bearing is ....

Mk1a (C50) 90365-25017
Mk1b (C52) 90365-25021

[SuperRedMR2]

Hi Paul,

Box has got to come off regardless.

I'll take it to my old mate whose been helping me out recently, so diagnosis will be confirmed.

Admittedly the box was outside, it was covered up 90% of the time but was exposed to wet weather and damp. I didn't think that the shaft would get damaged aside from the release bearing.

My stupid fault again.

[PW@Woodsport]

Yep if the box is allowed to sit in damp conditions the little needle roller bearing is the first thing to go, especially on a 30 year old one.... so it probably is the input shaft bearing to blame.

[SuperRedMR2]

Apart from that it's all running really well.

Could be an easy 3-4 hour job. All bolts are not seized so it should be fairly quick and trouble free.

[SuperRedMR2]

Getting a box off a chap 5 miles from me with 80k so a result really