Hi Don,
I use the Penrite Pro Gear 75w-90 in T/case and diffs.
Although the Lube Guide suggests Gear Oil 80w-90 the Pro Gear is a full Synthetic GL5 which I believe is better up here for the heat.
But it is a fair bit more expensive.
Cheers,
Paul.
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If its Penrite it's good.
I've always used Penrite for everything but I've got Trans Gear 75w-90 semi synthetic in the transfer case. IMHO semi or full synthetic is always better than straight mineral. I use Pro Gear 80w-140 full synthetic in my diffs (as one mechanic said to me, "I think that's a bit of overkill", but, like the gearbox, the Salisbury's do run hot).
Another interesting point is Penrite recommend their semi-synthetic HPR15 diesel over their full synthetic HPR15 for the 300tdi as the semi-synthetic has better soot suspension qualities than the fully synthetic.
I fired off an e-mail to Penrite Technical department:
I have a 1996 Defender and have religiously used Penrite Pro Gear 70w-75 in the R380 gearbox. There has been a shift away from Pro Gear for the R380 to Castrol Syntrans 75w-85 by both private and better specialist Land Rover service workshops as it reputedly gives a better, smoother shift with a higher temperature protection rating. As you will know, the R380 gearbox has an inadequate oil capacity which makes the box run hot, especially in slow offroad situations. I was just wondering what you recommend to give better protection and shift quality at high temperature (as in offroading) while still providing the cold viscosity required by the gearbox oil pump.
Here is the reply:
Based on your enquiry regarding your vehicle our recommendation is:
ProGear 75W-85 (Formerly known as SIN Man Trans).
Hey Guys, reopening an old post.....
I might have made a blue in that I too thought that the Defender Gearbox (R380) ran a ATF for the Gearbox and some months ago, I bought some to service my R380, but as yet haven't gotten around to replace the Gearbox Oil. From what I've read, I now should not be using ATF in my R380 Gearbox?
or can I? I live Queensland so no real cold weather as such.....
I have it in two of our Hi Ace vans manual gearboxes,including the one i drive,no problems so far.
FWIW,the Toyota stuff OEM(which is not available,even from toyota) does 200 000km,but the problem is they don't change at at the 200 000km,so buy around 280000km the vehicle has one whining gearbox[bigsad]
it maybe "ok" but it definitely isn't anywhere near as good.
seen it too many times now.
once gear changes start to slow down using the nylon, change to syntrans and after a couple of weeks the difference is obvious.
have yet to see it not improve a box running nylon..
always prepared for a first time tho :p
Found the following on the castrol website:
Manual Transmission
Service Refill Capacity: 2.7 Litres. See note 416 below.
https://www.aulro.com/afvb/images/im...017/04/523.jpg
CASTROL ATF DEX III
An automatic transmission and power steering fluid for use in GM automatic transmissions pre 2005 and in many automatic transmissions where DEXRON® (II or III) or MERCON® performance is required.
NOTE 416 states:
416With R380 manual transmission. For severe applications or towing use CASTROL SYNTRANS 75W-85.
My question: What is classed as "Severe applications"? -- Is 4WDriving classed as Severe?
driving in heavy traffic every day is classed as severe :p
Rob, MTF94, a 75W-80 dedicated manual transmission fluid superseded ATF as the R380 fluid from 1996 or 7, it was Land Rover's factory and dealer fill from then on.
There's heaps of info here in The Good Oil on why, alternatives, etc.
I prefer Penrite and have been running it, however when I could not get Penrite I did run Nulon and found it to be fine. When changed did not appear to be any overheating - burning of oil, colour had not changed. Syntrans is ok as well but way overpriced and no better than Penrite IMHO.