X-6 squared loud gearbox problem

[Jamie.T]

Hopefully someone here can point me in the rightdirection. The problem ive got is that the car makes a very, very loud high pitch sound when you rev it. Its the kind of noise when the wrong pitch pinion is meshed with a spur. (and yes i have checked that lol)

Ive slackened the slipper to try and it still makes the noise, ive stripped the gearbox and all the gears are meshing 100%, any ideas?
Thans in advance

Jamie......

[redonesgofaster]

...dodgy bearing ? .......


Ian

[Wraggy]

is it making the noise when ur driving it round or revving with the wheels in the air ???

[Jamie.T]

It makes the noise on the ground and with the wheels off the ground.

Jamie........

[mark christopher]

heard that a slightly worn idle gear can cause gear box noise

[Big E]

My guess would be a worn gear in there, maybe even a worn pinion, they can make a strange sound.

Ever since we have had the 4 gear we have never had any issue with it so I reckon it is a gear. I have actually only just changed all my gears as I just thought I ought to after having them in the car for a year and a half

[Jamie.T]

Cheers guys, i will change the gear tonight and try it again. Also when i re-build what grease would you use, a little moly axle grease or silicone diff lube? or just plain grease?

Jamie....

[Wraggy]

dont use any grease on the gears at all, you run them dry.
only in the diff of course

[bigred5765]

We had this problem a while back, Changed both ilder gears and diff gear and the problem went away.

[super__dan]

Did you build a 4 gear box using old gearbox parts and the 1 new idler? If so that's your likely problem. Ref gear grease, everyone has their own opinions, personally I use a little smear of this teflon stuff I've had for years. As with Ellis, my gearbox internals out last the rest of the car in terms of wear.

[Jamie.T]

Ive usd the same idler gear and diff that came out of my b4, and that didnt make any noise. Is it maybe that the idler has worn and ive installed it the other way around maybe?

Maybe best to just change the gears anyways.

Jamie....

[Big E]

That will almost certainly be the problem.

I'd go for a new idler gear.

Personally I do run a little diff grease on my gears just to keep it all smooth.

[Southwell]

+1 on grease, ive alwasy maintained it keeps them smooth and spinning freely and my gears always outlast the actual car. I'd say idler gear too, even slightly warn ones can make horrible noises.

[Wraggy]

seems to be personal preference, i have never used grease on my b4 and im using the same gears in my X6 which is now over 2 years old

[Body Paint]

If your not going to strip your box regularly I don't really see the point in greasing the gears as it will only spin off the gears and sit on the inside of the gearcasing gathering dirt.

Having said that if you really feel the need to use grease then I would say it has to be the same as you have put in your diff (which should be silicon diff lube) other wise you may get cross contamination and screw up the diff settings.