Phil G Old cruiser gearboxes

Missed the point, box is a 89 that hada 2H boat anchor in front of it.

I use Nulon in Gearbox, TCase, diffs and engine, believe it helps. Vehicle has had Valvoline oils since new. Dearer oils maybe better and may not need Nulon (may contain the same suff).

Peter

Phil
My view as a diesel mechanic is if its not broken don't fix it, by that I mean if its not making noise, not generating metal and operating ok, I would leave it alone. With oils, years ago I was working for tour operator and due to the loads and heat in a harsh environment on Cape York we ran 80W90 in the gearbox and 85/140 in the transfer case ( Landcruiser Troopys and Arkanas). However for normal Joe I would simply stick to manufactures recommendations. Keep oils clean, keep water out and maybe elevate breathers up under the bonnet. Oil is cheap prepared to repairs so if in doubt, change the oil out.
Cheers
Steve

Rockape,
No magic suggestions. I guess theres the odd downside to having 6.5 litres under the bonnet when the gearbox is made for a 76Kw motor. But the vehicle is 20 years old. If its any consolation, the gearbox that came in the early 78series was not as good as yours!

Steve's comments above are sensible.

Have just had our gearbox (and 3F motor) rebuilt as you propose - had done 350,000+kms. Very happy with the result.