Thinking about changing my stock rear gears, was wondering if it is necessary to run the stock 75w-140 again or can I change as long as I get something that will work with the limited slip?
Ok to change viscosity on gear oil?
- Thread starter KonaGT
- Start date
Why? You thinking thicker or thinner?
Royal Purple 75w140
I put in Amsoil severe gear 75w110 when I did my gear install 95,000 miles ago
no issue, I'm thinking of dropping it down to 75w90
Here is the thing I never under stood about Ford
they want me to run some of the thinnest engine oil out there, ( for fuel economy )but want me to run gear lube from a cement mixer. ( hurting the gain from the engine oil)
no issue, I'm thinking of dropping it down to 75w90
Here is the thing I never under stood about Ford
they want me to run some of the thinnest engine oil out there, ( for fuel economy )but want me to run gear lube from a cement mixer. ( hurting the gain from the engine oil)
Well I checked around at the local parts stores today and I can't get anything in a 75w-140 and I am wanting to change my gears tomorrow. So I don't have time to order anything.
You can run anything you want in there.
The question is how will a lighter gear oil effect the ring and pinion and bearing life?
That is something I would prefer not experiment with since the 75W-140 is readily available.
Unless you are racing in a class where every hundredth of a second is a huge deal, I don't think it's work risking buying new stuff.
I'd rather everything last as long as possible in there.
You can use any 75W-140 that is synthetic. Here are the best 3 you can use.
Amsoil Severe gear 75W-140
Royal Purple Max Gear 75W-140
Red Line 75W-140
Amsoil Severe gear 75W-140
Royal Purple Max Gear 75W-140
Red Line 75W-140
Easy helps keep gear an rearend noise down a tad.
I use royal purple 85w-140 I went with a little thicker.
Maybe a tad more viscous cold, but will be close to the same viscosity when hot.
Well been using it for about 20k no issues
Found Royal Purple 75w-140 locally so I used that.
Took me all day to swap the gears but I got it done and it doesn't make any noise yet lol.
Took me all day to swap the gears but I got it done and it doesn't make any noise yet lol.
That is always good news!
Tell me about it. I don't have very much patience and setting these gears up tested what little I have. If they made noise or something was wrong when I was done the car would probably be for sale.
Lol
what are the difference between 75W140 and 85W140. any reason to use one not the other? or are they specific for certain way you gonna use the car for?
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