A place for more technical discussions. Please make sure you post in the correct section on the site, this way it keeps the site tidy AND ensures you get a more relevant answer.
A few of us are running Redline MTL in the gearbox with good results. Avaliable from opie oils online shop in american quart bottles (2 small ones needed for a oil change). Not the cheapest, but does work very well and is a proper GL4 oil.
Transfer box (if standard) can use the same stuff I think. Diffs need EP (extreme pressure) rated oil (as per the bigjimny wiki info).
EDIT: forgot to say - some are using the reline oil to improve stiff gear selection. This problem is more likley caused by one of the following: Gearstick linkage bush worn/broken, Rear engine/gearbox mount worn/broken, Gearstick plastic bush deteriorated and finally gear selector mechanism full of cack. Note that the selector mechanism is external to the gearbox and not oiled by the gearbox oil (semi sealed unit).
J999 MNY, ULYSSES M18 VVT with ITB's Dyno tested at 130hp
Used a GL5 oil, Comma semi synthetic 75/90 in our 2007 car at circa 30,000 miles and replaced car at 60,000 or so with no gear change or gearbox issues at all.
Great change quality before and after the oil change.
