Guys, Book says for rear diff oil Motorcraft SAE 75W-140 and for manual transmission oil Motorracft Mercon V ATF oil. My question is how hard and fast on only using Motorcraft oils. Has anyone used a sub (Redline, royal purple, etc) and had any issues or gained better results. Getting ready to change mine and want opinions..

 

Update: I went with Redline for both trans and rear diff...seems to shift easier..

 

I went with Mobil 1 syn ATF for tranny not much different than what came out of it, did not look to bad 55000 miles.

 

I tend to use Amsoil whenever possible.
Just did a rear-diff fluid change on the fiancee's Shelby.
It got Amsoil 75-140 fluid, and both of these, trying to quiet down a dull whine during slow turns.
It worked! She's quiet now!

 

Finally got around to changing mine. I bought this
I used 2 of these plus the 4oz ford friction modifier. After getting it all in, I saw in small print on the oil bags that they already contain friction modifier. So do I have too much modifier?

 

Won't Hurt a Thing!

I Don't Know if They Are The Same as Back in The Day But That Vintage FORD Stuff Smelled Like a Dead Dinosaur!

KC

 

Thanks. Yes, it stinks really bad. Worse than dinosaur dung.

 

yeah I think you will be OK .... if you find that you are getting "one wheel peel" then it might be too much friction modifier

 

I used that same stuff. I talked to Valvoline about it and they said do not use friction additive with this particular blend.