Differential Oil Additive
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Differential Oil Additive
I just finished putting in a rebuilt 3rd member in my 77 RAnchero 500. New 3.73 gears with limited slip. Someone had toild me that I need to put some kind of "limited slip addiitive" to the gear oil. I am currently putting in Lucas high performance 80/90W gear oil. Anyone know? How many quatrs of oil does the rear end take?
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From: So Cal
Assuming your limited slip is like modern(says 90s and newer), you could use limited slip additive from StaLube. It comes in large toothpaste tube type containers. Don't know how much your Ranchero would need. Usually 1 tube is enough for a car type differential, two tubes for something like the 250/350 uses.
Some gear oils claim to already be compatible with LS so you may not need additive. If your rear end chatters in slow speed turns, then you need additive.
Wild guess on how many quarts for your diff is maybe 3 qts, but I have NO experience with your model.
Good Luck,
Jim Henderson
Some gear oils claim to already be compatible with LS so you may not need additive. If your rear end chatters in slow speed turns, then you need additive.
Wild guess on how many quarts for your diff is maybe 3 qts, but I have NO experience with your model.
Good Luck,
Jim Henderson
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I went to the Ford dealer and got what they call FEHP Friction Modifier. 4 oz for $6. It looks like the number is XL-7. NO directions on the label for how much to use. It refers to the owners manual or workshop manual. I did look again at the label for the LUCAS 80/90W high performance gear oil. It says that is is good with limited slip diffs, no addiitives needed. I think I wil put this on the shelf right now and see if I get any "noise" from the rear end. My car won't be on the road yet for about a month (going to paint in two weeks,so I will find out then.
Thanks for the inputs everyone.
Thanks for the inputs everyone.
