Differential fluid change - do I need friction modifier?

I'm at Auto Zone. Gonna change rear diff fluid. What do I need?

3 quarts of 75w-140 synthetic for stock cover, 5 quarts for mag-hytec cover. I always buy one extra quart just in case. If you have stock cover need new silicone to seal it back up as well.

Awesome. Thank you!

Don't forget the hookers and blow.

Hey Pirate, I got the canister purge valve on the engine ticking loudly, no Check Eng. light. Should I get a new one or just wait til it throws a light? Ford parts wants $60 for a new one.

Madcowranch said:

Hey Pirate, I got the canister purge valve on the engine ticking loudly, no Check Eng. light. Should I get a new one or just wait til it throws a light? Ford parts wants $60 for a new one.

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Just switch it out. Online Ford OEM is $20 IIRC. I have a spare that I will sell you for what I paid for it

Hey, don't our differentials require some kind of special additive? Something about their limited slip design, if I remember right.

are you still there? if you wait there a little longer, a few more people might chime in.......

Sorry I was off with the price (bought this almost a year ago). But here's the cheapest $36 if you have Amazon prime: Amazon.com: Motorcraft CX-2369 Fuel Injection Auxiliary Valve: Automotive

I paid roughly $40 for mine

---------- Post added at 10:32 AM ---------- Previous post was at 10:23 AM ----------

Ruger said:

Hey, don't our differentials require some kind of special additive? Something about their limited slip design, if I remember right.

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This is what the owner's manual says about the front diff: 1.8L of Motorcraft SAE 80W-90
Premium Rear Axle Lubricant

and for the rear diff: 2.6L of Motorcraft SAE 75W-140
Rear Synthetic Axle

Ordered off of Rock Auto last night. Thanks Humvee.

*** Busa.

Russ, I don't think we have LS diffs?