I traded my Jeep for a 17 silverado 1500. I have Amsoil 75w90 that I can use in my front diff, but wonder if 75W140 will be ok in my rear G80? I bought this for my Jeep, never changed it.
GM diff fluid.
- Thread starter WillB
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You don't have enough Amsoil for the rear ? That's going to do the high RPM work.
I have owned GM 4WD's for many, many years (have 2017 & 2018 now) and never went above 75w90 … mostly Mobil 1 or Delvac 1 75w90
I have owned GM 4WD's for many, many years (have 2017 & 2018 now) and never went above 75w90 … mostly Mobil 1 or Delvac 1 75w90
Thanks. I will order more 75W90, will use the 140 in mower gearbox.
Does the G80 require any additives?
Does the G80 require any additives?
Originally Posted by 4WD
You don't have enough Amsoil for the rear ? That's going to do the high RPM work.
I have owned GM 4WD's for many, many years (have 2017 & 2018 now) and never went above 75w90 … mostly Mobil 1 or Delvac 1 75w90
^^ I use the Delvac 1 75w90 in my G80 locker. It doesn't contain LS additives.
You don't have enough Amsoil for the rear ? That's going to do the high RPM work.
I have owned GM 4WD's for many, many years (have 2017 & 2018 now) and never went above 75w90 … mostly Mobil 1 or Delvac 1 75w90
^^ I use the Delvac 1 75w90 in my G80 locker. It doesn't contain LS additives.
Originally Posted by WillB
Thanks. I will order more 75W90, will use the 140 in mower gearbox.
Does the G80 require any additives?
The GM grape scented stuff does have some LS modifier. But there are plenty of people using Delvac 75w90 that doesn't have any modifiers in it.
On the flip side there are a lot of people using Amsoil severe gear on their G80's, the Amsoil has LS additives in it.
I talked to a blender about it when I was researching what to use in my 3500HD. The spec for the Grape scented 75w90 does call for LS additives in a very small dosage.
Thanks. I will order more 75W90, will use the 140 in mower gearbox.
Does the G80 require any additives?
The GM grape scented stuff does have some LS modifier. But there are plenty of people using Delvac 75w90 that doesn't have any modifiers in it.
On the flip side there are a lot of people using Amsoil severe gear on their G80's, the Amsoil has LS additives in it.
I talked to a blender about it when I was researching what to use in my 3500HD. The spec for the Grape scented 75w90 does call for LS additives in a very small dosage.
If we were talking about Texas, I'd vote for 75W140, but the OP is from Innisfil, Ontario. 75w90 is fine. I have 200,000 miles on my diiff using Synthetic 75w90.
Originally Posted by 4WD
You don't have enough Amsoil for the rear ? That's going to do the high RPM work.
I have owned GM 4WD's for many, many years (have 2017 & 2018 now) and never went above 75w90 … mostly Mobil 1 or Delvac 1 75w90
Same, and doesn't the newer GM's suggest 75w85 for the rear now? I simply put Mobil 1 75w90 in and call it a day. No issues.
I'm a bit anal with my maintenance...I change it once a year whether it needs it or not. Drive about 26,000 a year anyway.
You don't have enough Amsoil for the rear ? That's going to do the high RPM work.
I have owned GM 4WD's for many, many years (have 2017 & 2018 now) and never went above 75w90 … mostly Mobil 1 or Delvac 1 75w90
Same, and doesn't the newer GM's suggest 75w85 for the rear now? I simply put Mobil 1 75w90 in and call it a day. No issues.
I'm a bit anal with my maintenance...I change it once a year whether it needs it or not. Drive about 26,000 a year anyway.
Originally Posted by Snagglefoot
If we were talking about Texas, I'd vote for 75W140, but the OP is from Innisfil, Ontario. 75w90 is fine. I have 200,000 miles on my diiff using Synthetic 75w90.
Should be more than fine, his truck calls for 75w85.
If we were talking about Texas, I'd vote for 75W140, but the OP is from Innisfil, Ontario. 75w90 is fine. I have 200,000 miles on my diiff using Synthetic 75w90.
Should be more than fine, his truck calls for 75w85.
What's mind boggling is that the owners manual for a 2017 Silverado 1500 does not list changing the differential fluid as a maintenance item.
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Originally Posted by BlakeB
Should be fine. I think those call for 75w85, but 75w140 shouldn't hurt anything.
![[Linked Image]](https://www.bobistheoilguy.com/forums/attachments/usergals/2020/03/full-79604-42426-24049b4e_ad9b_4e62_b695_871fbe346355.png "[Linked Image]")
I live in a tropical climate with high temp all year round. Would I benefit from switching to let's say 85w-140 if my manual calls for 85w-90? Thanks!
Should be fine. I think those call for 75w85, but 75w140 shouldn't hurt anything.
I live in a tropical climate with high temp all year round. Would I benefit from switching to let's say 85w-140 if my manual calls for 85w-90? Thanks!
I just did my front/rear differentials on my 18 last weekend. The front calls for 75w90 and the rear 75w85. I used Vavoline Full Synthetic 75w90 on both differentials. 75w85 is difficult to find and expensive and is barely any different from 75w90. I think they do the 75w85 for CAFE on these trucks. When I had my 15 I did the same thing and had no issues there either.
You could probably run 75w140 as well, I really don't think it will make much of a difference either. Probably doesn't need it unless you are constantly towing heavy loads or racing the truck.
You could probably run 75w140 as well, I really don't think it will make much of a difference either. Probably doesn't need it unless you are constantly towing heavy loads or racing the truck.
![[Linked Image]](https://www.bobistheoilguy.com/forums/attachments/usergals/2020/03/full-79604-42474-afab017a_ac56_490e_bce9_55061433de21.jpeg "[Linked Image]")
80w140 Petro-Canada in my 3 trucks and Chevron in 2 company trucks. All GMC/Chev
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