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

Originally Posted by barney

the lt 85 and lt95 are two very different gearboxes.
the reason the '95 needs the lighter engine oil is that it uses a mechanical oil pump to circulate the oil which is driven by a nylon coupling (don't ask me why). this coupling cannot handle the extra load put on it by a thicker oil and often strips out, making the pump inoperative and thus shortening the life of your previously bulletproof gearbox. the manuals tell you which oil to use, is doesn't get any more black an white than that.

NO - The LT95 and LT85 are pretty similar in that respect, they BOTH have a fibre/plastic gear in the oil pump - so the same goes for both. Only the LT77/R380 have a metal gear. The lower viscosity is also required so the oil reaches all parts of the box.

Engine oil is FAR LESS THAN IDEAL. It is better than EP90, because it is less viscous, but proper low viscosity gear oils are MUCH BETTER.

Mal Story (Maxi-Drive) reckons that the stories about the shafts/gears breaking are overrated. He said the only boxes he has seen (in his many, many years of rebuilding them) with sheared gears, were a couple of LT95s taken to the snow with EP90.

the manuals tell you which oil to use, is doesn't get any more black an white than that.

the manual's also tell us to use ATF in R380's, yet a 75W-80 gear lube has been factory fill since at least '98......
TSB's however tell a different story.

Oil technology has progressed somewhat since the mid eighties........

thanks everyone for the fantastic response.

I should have indicated the army data plate with the 110 indicates as follows:

engine OMD115
Gearbox OMD115
T/fer box Castrol FMX
PTO OMD115 (not that I have one)
Axles OEP220
Swivel Pin Housing OEP220
Power steer OX46 or OX47.

I had no idea what these meant.

Hi Peter,

Has yours got the taper roller brg conversion done to the transfer case? I was under the impression that all AMF Landies got this. Anyone confirm this?

JC

Gidday all,

Yes all Perentie 110s have the tapered roller bearing T/case. Very easy to retrofit into the civilian model. If they tell you it won' fit, they've never done it.

I have.

The oil pump drive gear was a bakelite shaft. The army did a mod which replaced this with a steel shaft. No more proflems with oil pump drive gear not working.

Tony

No unfortunately not army box (as indicated by bolt head at rear of box).

It does appear to have a high speed transfer. Box feels pretty good.

thanks

Peter

Castrol Syntrans is the BOM! It's advertised at 75-90W but it thin like water. The G/box an T/case in mine don't ever get hot, no cold shift problems what so ever. Can't recommend it enough.

Cheers

Originally Posted by Larns

Castrol Syntrans is the BOM! It's advertised at 75-90W but it thin like water. The G/box an T/case in mine don't ever get hot, no cold shift problems what so ever. Can't recommend it enough.

Cheers

Syntrans is 75W-85 (11.9cSt @ 100*C) Syntrax is 75W-90 (14.something cSt @ 100*C)
Both are excellent manual gearbox fluids.