Thread: Defender TD5 gearbox oil?

We use Syntrans in the gearboxes and either Syntrax (synthetic) or 80w/90 gearoil in the transfer case. Earlier t/cases always ran on the 80w/90, only with Discovery II did the recommendation change to synthetic (as far as I know).

I run Penrite MGO75 in the gearbox, Syn 75-90 in Diffs and TC and HPR in the Engine....

Excellent performance and value for money.

Originally Posted by BigJon

We use Syntrans in the gearboxes and either Syntrax (synthetic) or 80w/90 gearoil in the transfer case. Earlier t/cases always ran on the 80w/90, only with Discovery II did the recommendation change to synthetic (as far as I know).

What oil change intervals do you use for Syntrans and Syntrax? I understand that MTF94 is semi-synthetic and it gets changed at 40k.
I have Syntrans/Syntrax and thought 80k changes might be appropriate.

Thanks.

Originally Posted by Graeme

What oil change intervals do you use for Syntrans and Syntrax? I understand that MTF94 is semi-synthetic and it gets changed at 40k.
I have Syntrans/Syntrax and thought 80k changes might be appropriate.

Thanks.

the problem I have with extended drains in the R380 and LT77 is their limited oil capacity vs contaminent build up. Have close look at oil drained out in a clean container in sunlight. The amount of brass, etc is very apparent. Also remember that the bretaher/vents are unfiltered.

In large trucks with large oil capacities, Syntrans is good for 400,000km with used oil analysis. UOA's just aren't worth doing with such a small sump.

Transfer case oils at 40 000km, regardless of type. Gearbox oil every 20 000km. I never stretch any service intervals on my own vehicles, regardless of lubricant type. It is much cheaper to change oil than recondition or replace major components.

I have just ordered 3x3 of castrol oil, syntrans and syntrax at about $20 per litre. The 20 litre drums were $278 and $298 respectively. At lot cheaper if you can use that word than the one litre bottles but without someone to split it with the oil will probably be contaminated by the time I get round to using it all.
Cheers Scott

Originally Posted by BigJon

Transfer case oils at 40 000km, regardless of type. Gearbox oil every 20 000km. I never stretch any service intervals on my own vehicles, regardless of lubricant type. It is much cheaper to change oil than recondition or replace major components.

Thanks BigJon, I think. I may have to rethink my strategy - $75 in gbox oil every couple of months is a bit hot. Might have to use-up the rest of the MTF94 drum then start using some of the Mobil 424 oil I use in my farm equipment. But then I rarely change gears so longer intervals might not be such a problem.

I have a service schedule for the Disco MY02 onwards that shows gearbox oil changes at 40K, same as Xfer case oil.