Which oil for diffs?
Cargo Master
Joined: Oct 2008
Posts: 3,330
Likes: 13
From: Eaton, CO
I've been on top of it and monitoring it. I keep adding more little by little. Then it seems fine until a solid run on the highway after it warms up really good. It's annoying.
Post Fiend
Joined: Feb 2008
Posts: 10,977
Likes: 5
From: Lancaster, Pa.
IMO, I know the fluid isn't cheap but at this point, I would change out the Vavoline and start out fresh, maybe going back to the Motorcraft with the 5oz of FM. At least you know thats what the rear calls for, the full 5oz's or very close to it. When I decide to changeout my RP fluid, I,m going back to the Motorcraft, its synthetic but I'll feel better about it being in there.
Post Fiend
Joined: Feb 2008
Posts: 10,977
Likes: 5
From: Lancaster, Pa.
Dang, mine must have been on sale because it was about 9.00 a quart at Pep-Boys, 75-140.
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Fleet Mechanic
Joined: Jun 2009
Posts: 1,346
Likes: 4
From: Connecticut
Yea, I think ill just get motorcraft and add the f/m.. By the way, looked at my front diff cover and its really rusty. To the point of it would take forever to clean it up if I even could. Anybody change out their front diff cover? What it cost?I see some on ebay chrome for 25 bucks but I imagine it would rust quick in the winter.Ill prob go with the oem one. Wish they made a finned one for the front like I got for the back for the same $$$..
Logistics Pro
Joined: Jul 2009
Posts: 3,635
Likes: 3
From: Lansdale, PA
I juSt got my finned cover also and the napa had valvoline for 14.56 and purple for 15.37. So I got 3 quarts thinking it's enough but I guess not. I'll pick up another before I do the swap. Very nice cover. I'm happy.
Cargo Master
Joined: Oct 2008
Posts: 3,330
Likes: 13
From: Eaton, CO
IMO, I know the fluid isn't cheap but at this point, I would change out the Vavoline and start out fresh, maybe going back to the Motorcraft with the 5oz of FM. At least you know thats what the rear calls for, the full 5oz's or very close to it. When I decide to changeout my RP fluid, I,m going back to the Motorcraft, its synthetic but I'll feel better about it being in there.
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Posting Guru
Joined: Sep 2005
Posts: 2,476
Likes: 2
From: Monroe Michigan
When I replaced my diff cover three years ago, the front and back covers were the same price $26.00 for O.E.M
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Fleet Mechanic
Joined: Jun 2009
Posts: 1,346
Likes: 4
From: Connecticut
For that price its not worth the time to scrape and repaint. Ill buy another.. Thanks..
Posting Guru
Joined: Sep 2005
Posts: 2,476
Likes: 2
From: Monroe Michigan
I would say yes, but there is some confusion on this, read this https://www.ford-trucks.com/forums/8...id-change.html and see what you think.
Lead Driver
Joined: Jun 2003
Posts: 8,298
Likes: 25
From: Damon (South East Texas)
Specs call for 6.9 pints for the rear axle.
Posting Guru
Joined: Oct 2008
Posts: 1,825
Likes: 2
From: Az
Yea, I think ill just get motorcraft and add the f/m.. By the way, looked at my front diff cover and its really rusty. To the point of it would take forever to clean it up if I even could. Anybody change out their front diff cover? What it cost?I see some on ebay chrome for 25 bucks but I imagine it would rust quick in the winter.Ill prob go with the oem one. Wish they made a finned one for the front like I got for the back for the same $$$..
Kinda neat,but pricey