i have a 98 2.8 st td ive owned it for about 4 months and planning on heading east in it from perth WA, i have a  question on it, its also the first time i have owned a turbo diesel and 15 years between stints in owning a 4be,1) when im driving it in 1st and second gear in peak hour doing say between 5kmph and 25kmph its quiet  noisey  from the gearbox area,but after i get over 30kmph the noise goes away, also when at idleing i can hear it but not so noisey and when i push the clutch in on idle it dissapears, its a chainy type of noise, im wondering if its either the gearbox or the transfer case, if its the transfer case is there some way of lessening the noise? is it possible to do any adjustments to the transfer case or give it an overhaul as i dont want to be forking out 4+ grand to nissan for a new transfer case as i hear nissan have the monoply on that part,

I'd drain the oil first. If it is really contaminated than you'll know. Patrol's transfer box is usually bullet proof. If the chain is worn it can be replaced. Its more noticable when in 4WD mode.

You can change to sligthly thicker oil if in hotter areas as in colder places Nissan recommended ATF fluid instead of gearbox oil 75W-80. It is also recommended if you have auto hubs.

What you are describing sounds like gearbox though especially because RD28 uses weaker/smaller gearbox than its other cousins ZD30 or TD42 which is more prone to failures.

Regards

Edited October 2, 201411 yr by Rumcajs

While your under the bus give the uni joints a few pumps of grease.

You could be looking at a pre failure joint noise. Grease will pack it for a short time so if the noise goes but comes back in a few kilometres then I'd be investigating further