Thread: LT85 Gearbox and transfer oils

Hi all. I rebuilt my gearbox and transfer in my county about 6 years ago and guessing about 50000km since and have pull it out as it was getting noisy. I expected to find the layshaft bearing at the back of the box to be worn out which it was ( i use 5th gear too much as i have a 4.4 v8 in it ) but i have found all of them buggered! While i had it out i am changing the high range ratio. I found all the bearings were buggered as well! I have been running castrol VMX80 in both which is supposed to be a good oil and meets all the specs for both the box and xfer. My truck is an 85 V8 county with the 4.4 leyland v8 all tricked up and efi'ed. Is there anyone out there with a similar vehicle ( i dont believe a 300tdi in a disco in the city would cop the workout that my truck does. Not putting anyones vehicle down!) that is running a different oil that they can recommend that has done reasonable distance? It is fully loaded all the time and often has a ton on a trailer behind going bush ( I have a company car) Tim

Castrol VMX 80 is OK for your LT230 transfer case but not for your LT85 gearbox.

LT85 owners used to use ATF or engine oil but in recent times a lot of the lighter gear oils have proved to be superior.

Among the appropriate oils, Castrol Syntrans 75W/85 has become a popular alternative.

So, from your comments it would seem that your use of extreme pressure differential and gear oil in your LT85 hasn't helped it at all.

The use of EP oils in the LT85 is certainly not recommended by Castrol Castrol Australia - NetLube or in any of the LR handbooks/technical manuals.

Sounds like you're up for another rebuild or a replacement with one of the other alternatives - unfortunately