Thread: Oil Recommendation for LT95 4 speed box and Isuzu 4bd1

Sorry to BUMP this thread as a brand new member (and as my first post), but I have an experience I would like evaluating:

2 months ago, I noticed oil migration FROM the transfer box of my LT95 INTO the main gearbox. I did some research and heard great noises about Blue Devil Transmission seal conditioner. Around this time I also read this post on LT95 oils, and plumbed for the only synthetic I could find here: Redline MT90.

2 months and 3500miles later, and oil is now hemorrhaging from my LT95 input oil seal and dribbling out of my bell housing like the preverbial trail of cookie crumbs. This seems to be related to a more significant failure of the transfer/main gearbox oil seal (as the dribbling becomes much worse when the main gearbox becomes over full -- which now does not take long!).

What I am curious about is:
Do any of you think this Blue Devil Transmission Oil Seal Conditioner is at fault, or is the MT90 culpable -- or was it a tag-team effort?

Is there anyone who has run Redline MT90's in their LT95 without drama (I also have a Fairey Overdrive bolted in there)?

-- I have found a relatively good (from what I can see of the general gear condition) LT95 from a guys shelf (though it was stored for some time covered and without oil), and will be throwing it in this week -- so I would like to know whether or not to stick to the MT90 (which actually reduces cabin noise by almost 20DB!!!!!!!!!!), or return to Castrol GTX (with which I had no problems.

It might be worth pointing out that my rangy (Jen) has just flipped the 1,000,000Km mark -- so I am not ruling out co-incidence.

Thanks in advance!

In the lucky country we just join both 'chambers' of an LT95 together with bog standard plumbing fittings and let them both share the viscous love.

Plenty of info if you search.

cheers, DL

Just a comment - the oil from your bell housing is more likely to be leakage from a warped cover on the oil pump on the front of the box than from the front seal, although both are possible. Easy to fix - once you have the box out!

John

Originally Posted by djam1

DONT put 90w gear oil in the transfer if you do the GL5 oil will destroy the shims in the transfer and it will all turn to rubbish.
Rover recommedned engine oil at 20w 50 the army uses 15w 40 castrol.
These boxes are incredibly tough 20w 50 seems to have them last up to 500,000 ks.
Be very wary of modern uninfomed advice.

Wow

hi there, I go by the range rover workshop manual and use 20w/50 multigrade engine oil in both transfer case and gearbox. I also use the same 20w/50 in the engine. But I don't like when I am 4wdriving up a long steep hill loaded up with camping gear, I just feel that the 20w/50 is not protecting the gears like a gear oil,or manual transmission oil would. I buy a cheap 20w/50 and change it more often than required.
thanks from peter

Specialist gear oils are 'specialised' for extreme pressure and sliding surfaces, such as are encountered in hypoid gears and to some extent in spiral bevel gears. These are not used in these gearboxes. Manual gearbox oils are specialised for optimum performance of synchromesh clutches, and there is a case for this improving gear changes in the boxes in question. But they were designed to use engine oil, and it is difficult to see why even severe use would lead to lubrication failure.

More frequent oil changes are not going to hurt, but I am doubtful that they offer more than peace of mind.

John