my front diff says 75w90 gear oil on it, i was wondering if 80w90 gear oil would work, the reason i ask is i can get 80w90 for a couple bucks cheaper, also how much oil does the front diff hold? thanks for any help

 

its fine, just fill it tell it overflows.

 

I use 80/90 gear oil, no prob. Its either 1.6 front / 2.2 rear. Thats for an 88 4cyl. (ifs front)

 

sorry i forgot to say i have a 90 4runner v6 3.0 5sp 4x4
so pennsoil 80w90 gl-5 gear oil will work fine? i thought it might but the dealer said
" they recomend 75w90 for a reason"

 

GL-5 is perfect and 80w90 is perfectly fine (that's what I run, but in synthetic).

 

it wont make difference, mabey as them what the reason is? ive been running a 50 50 mix of water and whatever grease the po had in it in my 87 since this summer waiting for it to crap out on me so i have some motivation to put the solid axle under it but so far its been staying strong haha i dont recomend that tho

 

80w-90 GL-5 is fine for the diffs and transfer case.

GL-4 oil is better for the manual transmissions. The only dino version I've found is Sta-Lube sold at Napa.