Amsoil question

[Ryan]

Hi guys.

I placed an order for some 75W90 "severe gear oil" for replacing rear diff oil. Now they don't have any in stock as they were sent the wrong item. What they do have is 75W140 which they say just has a higher temperature rating.

Is it OK to use this in our rear diff?

Cheers!

Ryan ("Ingletor")

[Kenneth]

Hi guys.

I placed an order for some 75W90 "severe gear oil" for replacing rear diff oil. Now they don't have any in stock as they were sent the wrong item. What they do have is 75W140 which they say just has a higher temperature rating.

Is it OK to use this in our rear diff?

Cheers!

Ryan ("Ingletor")

Best wait to heard from Don (Amsoil) as I am sure he will enlighten you.

[Ryan]

/me waits patiently for Don. BTW - they didn't have any 5W30 engine oil but they do have the 0W30 which I've ordered.

[bradc]

0w30 is even better

[amsoil]

SVO is what I consider to be overkill in Aston DBR9's who are main customers for this product. Even Le Mans cars only use the SVG . There is an inbetween oil called SVT (75w-110) which would be preferable. IMHO I would ask about FGR 75w-90 (GL4/5) then the SVT and finally the SVO.
The reason for such a thick (when hot) oil is to maintain protection in extreme heat conditions; the heat will actually thin down the oil to be near to the 90 part of the 75w-90, but at a higher temperature. All these oils are the same thickness when cold/cool its just that the 75w-140 thins down less.
Hope this all makes sense to you.

[Ryan]

(post deleted)