gear noise

I have now been running my defender K plate 90 200tdi for eight months sinse a chasis rebuild. I have got to know every rattle and clunk that my landy makes and enjoy using this vehicle every day for my work.
About a week ago I noticed that 4th and 5th gears started to whine softly over 50mph. Is this something to be concerned about or is this normal??

When did you last change/check your gearbox and transfer box fluids? Have you got the right stuff in them?

I've also got a K reg 90 and my box makes a whining sound when I let my foot off the accelerator (backing off) and this only happens in 3rd, 4th and 5th. May be related faults which I was just putting down to a loose bearing. I'm not touching mine as it doesn't affect the driving (yet) and I've kind of got used to the sound

Fluids were checked and topped up in April. No leaks from transfer or gear box other than slight weeping here and there. Landy is pulling well and this noise only occurs when I am feathering off the power in 4th/5th so i will leave things alone for now.

Mine does the same, but the noise is quite annoying now...

My old disco started like you described, slight whinning noise.. I didnt do anything about it and 500 miles later the transfer box was gone..

I've heard about this thing called molly slip, which reduces the whining noise and helps, but Ive put a thread about it in General but doesnt look like anyone uses it...

just a quick up date for anynone slightly interested.About 1,500 miles later gear noise is just the same and no worse. Ive got used to it now and Landy is driving well. I found out that a new box had been fitted before i owned it because I met up with the mechanic who serviced the vehicle. Perhaps the gears have just bedded in and now produce the usual transmission noises that all landy's make. Who knows?? Still enjoying the drive though!
DC

If box was a recent change and has now done a few thousand miles ,change oil and clean its filter to remove any small particals that are a result of new parts bedding in,may help with noise certanly help box last longer.

I had same or simlar noise from my 200 on the over run though, it turned out to be the taper bearing on the main shaft gear, you know the one with[ holes/or with out] if early badly pitted, take PTO cover of have look/se dos'nt take long.