75w140 instead of 75w90

[Jake_Wade]

I have a 2008 Silverado 1500 extended cab. 75W90 is the recommended rear diff oil.

I dont pull a trailer alot but it does get very hot here in Louisiana. Would 75W140 give better protection/longer bearing/gear life?

Or should I just refill with 75w90?

Thanks!

 

[Barkleymut]

Its hot in 80 percent of the country in the summer, run what the manufacturer recommends

 

[oggb]

I'd drain/refill with 75w-90. The rear differential is generally the last thing you need to worry about killing in a truck that doesn't haul/tow heavy loads on a very regular basis.

 

[Barkleymut]

and it ain't so much the heat.....its the humidity!

 

[chubbs1]

Stick with the 75w90. Use a high quality brand and you will be more than good. I recommend Amsoil for gear oils.

 

[oilboy123]

If running synthetic I would stay with the 90wt.

 

[Tros]

Use what the manufacturer recommends. If I am remembering correctly, GM put synthetic gear oil in their pickups from the beginning. Don't quote me on that though.

 

[Pablo]

Originally Posted By: Jake_Wade
I have a 2008 Silverado 1500 extended cab. 75W90 is the recommended rear diff oil.

I dont pull a trailer alot but it does get very hot here in Louisiana. Would 75W140 give better protection/longer bearing/gear life?

Or should I just refill with 75w90?

Thanks!


No. Use Amsoil 75W-110.

 

[dubie2003]

Instead of spending 20 a qt on the 140, spend 10 a qt on the 90 and change it twice as often if you feel the need. There is no pint in going 'thicker' u less your overall driving habits would benefit from it.

 

[MetalSlug]

If you need it right away, use mobil 1 75w90, and if you can wait and get online, use redline 75w90.

 

[Turk]

Originally Posted By: Pablo
Originally Posted By: Jake_Wade
I have a 2008 Silverado 1500 extended cab. 75W90 is the recommended rear diff oil.

I dont pull a trailer alot but it does get very hot here in Louisiana. Would 75W140 give better protection/longer bearing/gear life?

Or should I just refill with 75w90?

Thanks!


No. Use Amsoil 75W-110.


+1

 

[Jarlaxle]

Originally Posted By: dubie2003
Instead of spending 20 a qt on the 140, spend 10 a qt on the 90 and change it twice as often if you feel the need. There is no pint in going 'thicker' u less your overall driving habits would benefit from it.


Walmart has 75W-140 for about $11.50/quart.

 

[meep]

my two favs are mobil 1 and amsoil. i've also used valvoline syn, but the mobil and amsoil actually have a different "feel" and the pedal... hard to describe, which I didn't get with valvoline. I run the amsoil 110 in a vehicle spec'ed for 140 and it's been a great fluid. by that I mean I've done some wheeling with it, lots of tire spin on rough climbs, and fluid always looks clean when I check it.

 

[LckydevL]

I would think the only reason to go to 75w140 would be that you tow a heavy trailer most of the time.

 

[Loobed]

Originally Posted By: Jake_Wade
I have a 2008 Silverado 1500 extended cab. 75W90 is the recommended rear diff oil.

I dont pull a trailer alot but it does get very hot here in Louisiana. Would 75W140 give better protection/longer bearing/gear life?

Or should I just refill with 75w90?

Thanks!


I have a 2001 GMC similar to yours. I have tried a few different 75w-90 oils, and I think Amsoil Severe Gear 75w-90 is one of the best. I have not tried RedLine, but I might try it on the next change. I don't like Valvoline or Mobil-1. The factory fill also works great, but I don't know who makes it, and it costs too much from the dealer.

You will need 2-1/2 quarts for the rear and 2 quarts for the front. The front takes 80w-90 dino, but you can use 75w90 synthetic. I changed my front differential to synthetic, but didn't get any mileage increase.

 

[Jarlaxle]

Originally Posted By: LckydevL


I would think the only reason to go to 75w140 would be that you tow a heavy trailer most of the time.


I did it per Jeep's recommendations for towing with a Cherokee. (Defaulkt recommendation is 75W-90.)