Thread: Fairey Overdrive on LT95 - Oil

It fills to the level of the xfer case, and shares the fluid to some degree. But when the xfer case fluid level drops, the fairey tends to donate it's fluid, leaving the fairey dry.

The fairey overdrive on the LT95 is different from the series OD with lubrication.
The LT 95 OD shares the transfercase oil by catching the oil vapour and oil throw off from the gears of the transfercase and funnelling the oil into the OD via two holes and the shape of the OD housing nose which fits inside the transfercase.
The excess oil the OD catches is returned via the needle bearing in side the OD gear.(this helps cooling and life of the OD compared to a series OD)
You have correctly intial filled the OD and then just check your transfercase oil as per normal.
If for some reason you lose the transfercase oil, the OD will survive as it will still hold some oil, even if the transfercase is empty.
Only use the OD in top gear and it will last along time.
Note some of the later LT95 ODs had a extra oil catch hole machined into the middle of the housing to improve oil shareing between the Two gearboxes even more.

Originally Posted by captainslow

I'm using Castrol VMX80 in the transfer case.
The Fairey manual recommends EP80

You should be using V8 engine oil in the transfer case/overdrive combo - it is what is recommended by Landrover.

What have you got in the gearbox - should also be engine oil.

Garry

Thanks gents. Ron, you're description makes perfect sense. I couldn't find that information confirmed anywhere so I'm most grateful. I was hoping that it was exactly as you have described. The OD works really well behind the 4BD1 and the LT95 - cruises very nicely at around 90k/hr.

As to the oil choice - I followed a very intense debate on this forum about oil choice and decided to opt for the VMX80 manual transmission fluid because this was proposed as having similar viscosity to the 20w/50 manufacturers recomendation but specially formulated for manual gearboxes (an option that wasn't available when the box came out). It seems like there are plenty of valid options, just don't use EP90.

Thanks again gents.
Pete

When you fill the transfer case, fill it via the filler for the Fairey and leave the filler bung out of the transfer.
When oil starts to come out of the transfer filler, both the transfer and Fairey are full.
Regards Philip A

Looks like you are on top of it all.

Originally Posted by garrycol

You should be using V8 engine oil in the transfer case/overdrive combo - it is what is recommended by Landrover.

What have you got in the gearbox - should also be engine oil.

Garry

I have been using castrol VMX80 in the gearbox for a long time.
It greatly improves gearshift action.
Oil specs have moved on a little bit since the old four speed was designed and the VMX 80 is a improvement over engine oil in this application.
VMX 80 is thin enough not to worry the gearbox oil pump and doesnt worry bushes ect.
I still use a GP50/60 engine oil in the transfercase, but I suspect some new oil could improve life, but most likely at a price.

Ron, I've used VMX80 in both the gearbox and the transfer case (and therfore the overdrive). The reason that I've done this is because I thought that the gearbox and transfer case may "share" a bit of oil.

Is this fair game or would you advise against it?

Cheers
Pete