I work at a BMW dealer in CT and I brought my 2004 disco into our shop and replaced the differential fluid with the fluid we use for all of our SAV's; it is Castrol SAF-XJ. I learned today that it is 75W-140 and I checked the Land Rover manual which recommends 75W-90 for the diff fluid.

I did the change about a month ago and so far everything has been fine.

Any thoughts about whether or not I should get this stuff out and replace it with 75W-90 ASAP?

Just wondering if anyone might know.

Thanks.

 

Leave it. Many guys with high miles step up to the more viscous fluid anyway. And working at the bimwah shop allows you easy access to replacement radiator tee bleeder screws....

 

The better fluid for both the diffs and the t/case is a 85/140 for a lot better wear protection, change to it when you can.
Since you just recently purchased the Disco, you might want to read my major service list posted at the top of this section and do it all, especially the front drive shaft, check it, if it doesn't have 1 grease fitting on each of the front 3 u-joints, it needs to be rebuilt or replace ASAAP because of their high failure rate that will usually damage the tranny in the process of breaking.

 

Mike-
I started doing all of the things on your sticky thread. I started with the serpentine belt, then the thermostat and cap, the wires and plugs (and coil pack). Then I replaced the ENGINE (no I'm not joking). After that I did the front and rear dif fluid and transfer case fluid. I took your advice and replaced the drive shaft (from Great Basin Rovers). At some point shortly after that I replaced the starter.
In 20 days I will have owned the truck for one year and I am still not finished with all of the things on the list.
Next up is the transmission fluid and filter and I am thinking about doing the O2 sensors. I have an occasional weird banging noise underneath somewhere...sounds like a bushing of some sort. I would like to replace the shocks but I need to pace myself on this. Its been a rocky road. I am hoping that over the long term it will be worth it as I plan to keep it for a while.

 

Sorry to say it but the 75-140 is perfectly fine, especially in the Castrol.
It will flow better when cold than a 85w- but still protect like the -140.

 

Check the rear flex coupler for the wierd noises.

 

Little help with the location of the rear flex coupler?

 

Where the rear u-joint on the rear driveshaft would normally be. So right in the front of the rear pumpkin. They used this as a vibration damper over a common U-joint, ironically when it starts to fail it causes much vibration.