Thread: what gear box oil to use

you'd be hard pressed to find Dex IID now as it was superceded by Dex III (which is also backward compatable with Dex II) which has since been superceded by Dex VI.
With all due respect to Bowler, an ATF is good for an AT tranny, but it's charcteristics don't suit a manual transmission with synchro's, and in my experience shift quality deteriorates badly and noise increases markedly in 35*C+ ambients with 11cSt + manual trans lubes, let alone trying a 7cSt ATF.
As Inc said, most transmision builders in Oz void warranty if an ATF is used in a rebuilt R380.

I've also tried quite a few oils and brews including MTF 94 and Redline's finest and have gone back to Syntrans for its better upshift performance. It's also Castrol Oz's prime recommendation for hard use in the R380 and is their prime recommendation for competition use and various Euro prime movers needing a 75W-85 trans lube. It's a very good lube.

I use the Penrite Sythetic ATF in both the LT77 ('88 Range Rover) and the R380 ('97 Defender). I tried the Penrite light gear oil in the LT77, but that was took chunky through the gear changes even driving across the Nullabour! The tech advise from Penrite was that the Synthetic ATF had better high temp stability than the light gear oil. It pretty well priced at about $30 for 4 litres (maybe a bit more retail).

Well I changed my gear oil today. That is after buying a T55 torx bit. What a pain that is to get a socket handle past the drive shaft and exhaust
I drained out some nice red ATF. When I took the filler plug out the fluid was higher than the filler! At first I thought it must have gotten some transfer case oil in it but the fluid was still red. However when I changed the transfer case oil last week it was very low. However it does leak quite a bit.
I ended up using the VMX80 instead of Dexron III. One reason being the Qlders here recommended it and the other being we needed the Dexron III in our forklifts this week
I haven't driven it much since changing the oil but it is a great improvement. I didn't think there was anything wrong with it before. It was just a little notchy but no different to the Rodeo I had before that. However when I did drive it I did a few quick changes to see the difference and the notchiness is pretty much gone.
It had a bit of a whine on the highway before but I haven't tested that out yet.
So far I am pretty happy with the change.

Thanks for the info.

My D2 improved in smoothness of changes and quietness so much with Syntrans that I then put Syntrax in the TC. It hushed the whine that was just starting to be heard.

Just done over 12000 kms with Dexron III in the box,this thread and other remarks worried me so I dropped it out.
Damage done,plug magnet looked like krusty the clown,metalic cloud in the fluid and some small small chips/ hardfacing to boot!!
Refilled box with Castrol Easy Shift 75/90,whish me luck and more overtime.

Originally Posted by scottyp

Hi all'

Its my first service for my 96 defender and I'm very proud, but when I looked at the online manual it recommends using ATF dexron 11D for the gearbox. Is that not automatic transmission fluid, anyway' :?

What sort of oil are you using.

for the diffs I used castrol EPX 90 GL5

Thanks in advance

Scottyp

Hi I use penrite oil in the main box the one recommended by them for landrover, beautifull smooth changes hot & cold, and i use mobil 80w- 140 in the diffs and transfer case, you would Be amazed at how it quietens things down! Better for it too.

Cheers Sumo

Originally Posted by Utemad

It had a bit of a whine on the highway before but I haven't tested that out yet.

After having done a few hundred kms with this oil I can say that the whine in the gearbox has not changed at all.

Still happy overall though. Best thing is it was free

Just done 1000kms after changing the box fluid on friday,but the damage was done and we left fith gear behind in Perth. Rolled home in forth ok,only one hour later than normal.
As a new box isin order perhaps I might give that Syn Redline a go