Thread: Maxi Drive Recommended Diff Oil

from the Oil guru (Rick130) Im using Castrol Syntrax in the front (rover) and Castrol SAF-XA rear alxe ,both are synthetic and I have MD lockers in both. I like the fact that Castrol make a good oil for each application in my truck, so I shop at the one spot and buy in 20ltr drums....to save a few $$$

Btw you can use the Syntrax in the lt230 also.

Advice on where you get your syntrax in 20L drums would be of interest please.

I get mine from Gibbs Trucks Parts. They have a few outlets in SE QLD. I priced around all the "auto" shops and they couldnt come close to being better than a 1 ltr price...then priced QLD Diesel Spares and thought I was on a winner.....until I rang Gibbs and they were about $100 a drum cheaper I buy my filters from them also.

Thanks for the posts - but can anyone tell me why you would put a transmission oil in the front and a diff oil in the rear?

What properties make them more suited to have different ones in each?

And reading the spec sheet to the syntrax it says not to mix with mineral oils are reduces properties - I suspect that means I need to flush the diff - qu is how?

Skiboy

Sorry, I forgot to add that my rear is a Sals. Different gear design, hypoid, requires a different oil. It runs hotter due to the shearing action of the teeth...... I think haha

Any decent 75W/80W-90 GL5 is ok for a standard Rover diff with a maxi.

Syntrax is a 75W-90 GL5 transaxle fluid so good for hypoid diffs (originally developed for the transaxle in the TWR Jaguar XLR-9/10/12 cars) and more than good enough for a Rover CWP.

One trucking industry consultant I know used it in Eaton truck diffs and found increased service life and lower operating temps, all against Eatons advice (IIRC their prime recommendation was an 80W-140 ?)
He proved it so well a slightly different blend (Syntrax E) is now an approved and recommended Eaton/Rockwell fluid.

For maximum durability and shock loading in comp use I'd use Neo 75W-90RHD or Redline Shockproof, (and maybe Motul Gear 300) but be prepared for sticker shock.

If you're changing fluid a lot, Caltex diff fluid with their Borate ester additive package is really good (Delo ESI 80W-90)
Apparently it's as good or better than most blenders full on racing fluids.
Lubrication Engineers also make very very good mineral based diff oils that outperform a lot of 'synthetic' fluids.


As Serg said, I prefer the heavier 80W-140 diff oil in a Sals as they get damned hot, particularly if you use a cast diff cover.
It's a shame that no one in Australia blends to the SAE 75W-110 spec, it's a really good viscosity compromise.

Repco have a sale on this weekend.
I just stocked up on some oils most are 20% off
Repco brand hypoid 80w-90 GL-5 $29.99 for 5 litres.

Originally Posted by rick130

Any decent 75W/80W-90 GL5 is ok for a standard Rover diff with a maxi.

Syntrax is a 75W-90 GL5 transaxle fluid so good for hypoid diffs (originally developed for the transaxle in the TWR Jaguar XLR-9/10/12 cars) and more than good enough for a Rover CWP.

One trucking industry consultant I know used it in Eaton truck diffs and found increased service life and lower operating temps, all against Eatons advice (IIRC their prime recommendation was an 80W-140 ?)
He proved it so well a slightly different blend (Syntrax E) is now an approved and recommended Eaton/Rockwell fluid.

For maximum durability and shock loading in comp use I'd use Neo 75W-90RHD or Redline Shockproof, (and maybe Motul Gear 300) but be prepared for sticker shock.

If you're changing fluid a lot, Caltex diff fluid with their Borate ester additive package is really good (Delo ESI 80W-90)
Apparently it's as good or better than most blenders full on racing fluids.
Lubrication Engineers also make very very good mineral based diff oils that outperform a lot of 'synthetic' fluids.


As Serg said, I prefer the heavier 80W-140 diff oil in a Sals as they get damned hot, particularly if you use a cast diff cover.
It's a shame that no one in Australia blends to the SAE 75W-110 spec, it's a really good viscosity compromise.

Thanks Rick - not sure I follow all the advice (novice here).

So bottom line what would you use esp as we may not have the water leak sorted yet so might be changing more frequently?

Any does anyone know what to use to flush this out with?

Ie best bang for buck with excellent protection.

SKiboy