Quiet high pitch noise, sometimes.... possible bearing?

[Rusteee]

Hi there

I'm hoping someone can help me, about a month ago I had the gearbox oil in my box changed (as in complete drain over night) to redline MT90 I think it was. Ever since then I have a had a problem where sometimes when car has been sitting overnight and cold, it will make a loud kinda rough grinding noise whilst idling, which will then dissapear when clutch is pushed in, and/or when car warms up. The second problem is apart from that noise, I get a very quiet high pitched scream, either when engine braking or accelerating, which again will dissapear once clutch depressed, or crusing at constant speed. Both noises only happen every now and then some days fine, somedays will do it. Could it be thrust bearing?

Cheers

[hoolio]

Yeah, I have had similar noises which in my case was from a thrust bearing - and the noise would disappear when you depress the clutch as it starts to slow down once disengaged from the flywheel. (if yours is a thrust bearing that is)

Mine only seemed to do it when the engine/box was hot/after a long run.

Good luck with the second noises...! Sometimes belts make higher pitched type noises - sometimes when they are on their way out.

[Lloyd]

The noise on the on/off clutch sounds like input bearing. The noise under load either way is usually a diff issue.

[Crucible]

Thrust will only make that noise on application, as above Input shaft bearings.

basically box out and strip down or go 2nd hand.