Jap 5 speed "noise" - What is it? and, How do I cure it?

[camB]

G'day there.

The same box has been in my car since I bought it (1991) and while it still works, it's sounding a bit tired. It's the only thing on the car that I haven't pulled apart, replaced, or rebuilt, so could I get some opinions from those with more knowledge than me?

Diagnosis first...
1) Gear lever "rattles" in gate in the top of the box (3rd and 5th). I'm assuming it's coz the plastic (or bakelite?) knob on the end disintegrated years ago.
2) Synchro on 2nd and 3rd is a bit dodgy - that's just a combination of age and brass I assume?
3) This is the one that I'm really concerned about... In 5th gear there's a whine/rattle/generally odd sound, but only whilst the gearbox is under load. Same revs coasting it's silent. It's actually done this for ages - but seems to be getting worse.

Any suggestions? And if the consensus is "rebuild", are replacement parts available? and is it something I can accomplish with the trusty Gregorys manual?

Thanks everyone for your wisdom.
Cam

[Billsy]

sounds like the syncros and one or more bearings are stuffed. mine has notchy syncros when cold and makes a little whine here and there aswell, its just an age thing with many of them

the only way to fix it is complete disassembly, measure and check everything, replace the worn bits and reassemble.
probably easier to find another one.

[regina]

I ripped one apart a month or two ago, cost me about $450 in bearings.
My suggestion would be if gears are damaged, just get a 2nd hand box or reco box.
But if it is just bearings may be worth the while repairing.

Cheers,
mick

[camB]

It's just 5th that has any noise whilst driving, and only when cruising or accelerating. Not when coasting.
Does this link it more clearly to buggered bearings or gears?

[Torana68]

without hearing it who knows , go see a mechanic and get an opinion, repair and investigation will both require dismantling but from what you said start looking for another box.

[tandanus]

I had a box (not Jap 5 speed) that made noise in every gear BUT 5th. I worked out what was wrong from studying a schematic diagram of the thing. (The only gear that didnt have the layshaft under load was 5th - the layshaft and its needle bearings needed replacing). So, study the diagram, come up with something that youre looking for, then take it apart and see if youre right. Gearboxes
T.

[camB]

Have just returned from 1500km round trip to S.A.
I reckon it's either the pedal or the actuating lever on the box. By accident I noticed that slightly pressing the clutch pedal (not to the point of pickup) eliminated the noise. I'll have a look and see what's rattly down there.

[81GL]

If its a werring noise. Thrust bearing.

[regina]

Any result?

[camB]

Nup.