diff oil?

[jotec]

i have a 06 montero. i bought castrol 75w-90 synthetic gear oil for the diffs. as anyone tried the synthetics in their trucks with any success?

 

[jotec]

oh it is gl5 also

 

[scrubber3]

To be honest, it really doesn't matter with these unless you bought synthetic for longevity purposes. More than likely there will not be any difference in anything but that. I could see where it may make a performance difference with an LSD differential as for as the friction goes. On an open or manual locking differential..... not so much.

BTW I have synthetic in my rear diff and it's fine.

 

[jotec]

i dont know if it is because my fluid had never been changed (or so im assuming) or because its a thinner weight, but it does seem smoother now that i have changed the fluid. it usually has a worse vibration feel in the pedal a little above 2k rpm. maybe im just use to the vibration and imagining it is better.

 

[Inyo_man]

I've been running Amsoil Gear Lube 80W-90 in the diffs. for over 100k with flawless performance.
Never once have I had to add any LS additives.

BTW My transfer case has seen nothing but Amsoil 75W-90 Sever Gear since I've owned the rig (flawless performance as well).