Whine can of course come from something that's turning, more in a gearbox it's more often when things are under load, be they gears or bearings. When coasting in neutral it's not under load. When decelerating using the engine, they are under load, but the loads are in a different place.
x2 on not taking it to a dealer. The one here in Atlanta doesn't even know Land Rovers came with 5-speeds. Ideally someone familar with R380's, but any good shop that knows manual gear boxes should be able to isolate the noise for you.

The synchronizers won't cause it to whine in general driving, but worn gear teeth will. But I wouldn't worry about worn gear teeth too much.

 

Yea, worn gears, worn hubs. Try a heavier oil first, try some Swepco, the stuff does wonders for older gear boxes.

http://www.swepcousa.com/lubesite/gear.htm

 

maybe the release bearing for the clutch??


I'm jealous....I wish mine was a 5 spd....lol

 

I am curious about what swepco you are recomending, the 201, 203, 210, or 212.

Don't think it is the throw out bearing cause its got a relatively new clutch. I do enjoy the 5spd.

I was told by an old timer about a product named whale sperm they used to put in tranny's to quit whine but he didn't know exactly what that is and man does that search pull up all sorts of crap on the net. Anyway, man-a-fre that does cool landcruisers has a product I've put in my fj60's that cut the whine out of that tranny. Came in a small tube and worked well. Might try that after the swepco products.

I don't think its something I'm gonna worry to much about as if its not fixable by changing a bearing it will be a long while before I feel the need to pull the tranny.

Meanwhile. I pulled a flomaster off a parts car I have to put on and its so loud I can hardly hear the whine. What a waste of stainless steel unless I sell it to a teenager! Man do I miss the quiet ride. I will be switching that back quickly.

Spike, its not really that they wouldn't look at my tranny, you are right, a tranny is a tranny, but more I really didn't want these yahoo's touching my car. Tom was talking of a r380 expert and there just aren't any here. Thanks all for the input!

 

Release bearing wouldn't be the issue because it only comes in to play when operating the clutch.

 

My 5-speed whines too. I think it's just Rover gearboxes, because mine only has 102K on it.