Gear Oil for Front Diff on a free-wheeling hubs?

Hello,

I just picked up a 96 Tacoma, I wasn't sure how the 4wd system works, but after reading the owner's manual last night, I realized my Tacoma has the free-wheeling hubs, not the Automatic Differential disconnect (ADD). With that said my owner's manual recommends 80W-90 for my front differential for NON-ADD for a change, along with 80W-90 for the rear.

Now my Haynes book, has the same oil viscosity recommendation for the rear, but for the front it says

$30 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90. Just wondering which one is correct? I just bough a gallon of Valvoline dino 80W-90 and just want to make sure it'll be OK for the both differentials. I plan on using Redline MT-90 for my manual transmission fluid, and probably dino Valvoline 75W-90 for the transfer case. The cost of gear oil isn't cheap lol.

I just wanted to double check the correct gear oil viscosity for the front. The dino Valvoline 80W-90 does say it works for hypoid. Not sure if I'm overconcerned and splitting hairs with these oils.

Thanks in advance!

 

it really dont make a difference

just avoid royal purple

 

Why's that?

 

I have used Royal Purple for years and have had no trouble at all

 

found to have the absolute worst wear of all the gear oils tested, Lucas is what ecgs reccomends

 

good to know too late for me at this point 115K so I guess ill just keep using it at this point

where can you see wear results?

 

Don't use royal purple ever under any circumstance!!! Likely the worst gear oil ever made. 15k diffs with royal purple look like they have 200k on them. It thins out and provides no gear cushioning and does not control heat.

he reccomends 85-140 lucas.

never too late to change also make sure the trans has gl-4 not gl-5, gl-5 has been known to eat brass

 

I just changed all those fluids today. I went with amsoil. There is a dealer here on TW that gives a great discount, making it the same, if not less then most of the stuff you get at the autopart store, minus their own brand.

Went with GL5

$30 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90 for the diffs, and GL4 75w-90 for the trans and transfer case.

 

Ok I'll change it soon then

 

Is the GL-5 oil OK for my transfer case? I already picked up Redline MT-90 which is GL-4 for the manual transmission fluid.

 

I run Amsoil everything (yes, even coolant) and have a combined 315,000 on my two Tacomas with no lubricity issues.

 

The MT90 is a great choice for the 5-speed. And yes, GL-5 is OK in the t-case, its only the manual transmission where you don't want to use GL-5.