75w85 vs 75w90 Gear Oil

[Mekks]

Looking to do the rear diff on my 22 Explorer ST.

It calls for 75w85 fluid. I already have 5+ quarts of 75w90 Redline....

Should I just toss the 75w90 in? I assume the thinner fluid is just for CAFE numbers???

 

[Snagglefoot]

Ford does have a 75w85 synthetic gear oil. Does the manual specify synthetic? I would say it’s for gas mileage in low loading conditions which it would be in an Explorer as apposed to a F250. Ford’s version states it helps with getting better fuel mileage. Amsoil make a 75w85 synthetic version. Might a well use the 75w90. You’ll just lose a bit of gas mileage and it would be interesting if your mpg drops a whole decimal point.

 

[Big E]

Yes

 

[Urshurak776]

I just did my sons Santa Fe. Also calls for 75W-85. 75W-90 went into both the differential and the transfer case. He's only been driving it for a week since then, but hasn't blown up yet!

 

[JavierH19]

They're almost the same, kv100 for 90 grade is only 2-3 cst more than 85.

 

[NiwradND]

Run 75w90 amsoil instead of 75w85 in Jeep Grand Cherokee for 50,000 miles now. Going back with 75w90 Amsoil on next fluid change.

 

[ctechbob]

I've always used 75W90 in place of what Ford calls for (For the F150 it is Synthetic 75W85). The Ranger didn't care and I doubt the F150 will either.

 

[Snagglefoot]

I saw something interesting in the 2022 Ford Explorer owners manual. Ford says oil changes are simply not required for the axles or transfer case. Having said that you can change the diff fluid every Sunday you want.

 

[Mekks]

I saw something interesting in the 2022 Ford Explorer owners manual. Ford says oil changes are simply not required for the axles or transfer case. Having said that you can change the diff fluid every Sunday you want.

Sounds like a good time. Thanks everyone for all the reply's. Plan on doing rear diff, xfer case, front diff prior to it getting really cold out.

 

[slacktide_bitog]

75w90 will be fine

 

[ctechbob]

Sounds like a good time. Thanks everyone for all the reply's. Plan on doing rear diff, xfer case, front diff prior to it getting really cold out.

Lol, I have that same exact plan.......the significant other keeps tossing wrenches in it. I'm sure I'll finally get to lay on a freezing garage floor and get it done.

 

[oldhp]

2024 GMC Canyon 4x4. GM puts "75W80" in rear gears. I ended up putting Valvoline 75W90 in both front / rear dif's. Didn't lose any MPG according to the trip MPG calculations.

 

[Lubener]

Looking to do the rear diff on my 22 Explorer ST.

It calls for 75w85 fluid. I already have 5+ quarts of 75w90 Redline....

Should I just toss the 75w90 in? I assume the thinner fluid is just for CAFE numbers???

Your Redline will be fine.