I'm not drilling your decision. If you want to do it then fine. I'm arguing that royal purple is not all its hyped up to be. In college we did analysis on all major brand oils including some cheapo brands. And you might be surprised how royal purple placed in our tests... And I will say Mobil 1 full synthetic placed the highest out of all the oils tested . Motorcraft was right up there with royal purple

 

If its as good as motorcraft, maybe a little better then im a happy camper. Like i said, i got it cheap on sale, cheaper then mobil 1. Plus its made in TX, woo!

 

Lol then it has to be good!

 

Looks like the cheapest I can get the diff cover is $120. I guess that's not a bad deal.

 

It's probably a good investment though

 

that heck with that 120$ cover unless your getting one that will work with a watts link.

 

I'm putting in a Trutrac and new girdle in my 5.0. I have 2 bottles of RP, I guess ill need more. It's actually at the shop right now.

 

Not sure about watts link clearence, but the Boss cover has internal and external fins that just have to help with heat dissipation.





It does clear the stock panhard obviously.



This is what I use to seal plugs 'n stuff.

 

Looks good!

 

When you complete the fluid change, let us know what the old fluid looked like and if you saw any metal shavings when you drained it. I was thinking of doing this just to get rid of the original fluid and put fresh in for longevity. Thanks.

 

All differentials should have some metal in them as the ring and pinion wear in. Once they are worn in changing the fluid is a great idea. so don't freak when you find fine metal particles in your oil. It's normal

 

FULL of metal shavings. They fluid was dark dark almost black and quite smelly. lol.

3 quarts of ATF fixed that though..

Only kidding. Royal Purple doesn't smell bad. Idk...why or why not..
I added 2 squirts of friction modifier.. no noise at all.
The magnet was very much so doing its job. It was so **** cold I forgot to take pictures.I added the ford racing diff cover, installed quite nicely. It is SO much more heavy and durable than the stock one. Flimsy is a good word to describe the stock one.

 

(The bottle of Ford Racing friction modifier was $3.99 at the ford house) Just FYI

 

Guys, if you see the crap that will come out of a rear end or manual tranny after the first couple thousand miles, you would think this is not a bad idea.

Yeah, I know, most people never change their rear end or tranny oil and most never have any problem. I like to change them out early, then make a 40,000 mi or so run before changing again.

Put any good quality oil you want back in, its not a debate about better oil than factory to me, just get the wear in crud out. Thing is though, the high end synthetics don't cost more than buying the factory stuff from Ford, so why not go with Redline, Amsoil, Royal Purple or such?

 

In our tests Mobil 1 beat our redline amsoil and royal purple

 

Crap....now another thing I "need" to do. I thought you were crazy doing this on a new car, but I kept my comments to myself. Now that I've heard what came out, I think that's a good precaution to take. Going to hold off till spring though.

On a side note, we just did the front and rear diffs on my Jeep a couple weeks ago. I used Amsoil thanks to way2qk4u2c, and now the thing don't feel like I threw an anchor every time I let off the gas.

 

If you want to put the aluminum cover on, order the replacement cover for a GT500 rather than the FRPP part. Same piece, different box. I got mine from Tousley Ford for under $70 shipped.

I did not drill the cover for fill/drain plugs but I did move the vent from the left side axle tube to the hole already drilled and tapped on the top of the new cover. That was the point (for me) of point the cover on - move the vent to the center and move it up higher so it won't spew when the diff fluid heats up at an autocross or on the track. You'll need to find a short cap screw (bolt) to seal the hole on the axle tube.

You won't get a gasket with the aluminum diff cover but you don't need one. Use a good quality RTV gasket material from a tube. Ultra Copper is good as is Ultra Black. Both are from Permatex and are good in high temperature applications.

Finally, I filled my diff with Redline 75w140 gear lube. It does not need a friction modifier in clutch style LSDs like Ford used on your GT.

Carry on...ned.

 

No joke, you could see all the metallic sparkle as it flowed out. Magnet was full too. For the $38 in fluid it cost, it's well worth it.

 

Here's a little bit of what flowed out after 1200 quiet miles on mine. I think it was good quality time with my car to change it out. Not expensive for me since the cover was factory.

 

Hi

I have a 07 mustang v6 manual trans with 24k miles, just bought it, I am planning to flush motor, transmission, gear lube. Break oils, I have heard that royal purple is good, I would like to know if any other brands are better than rp, also the best oil change shop I can trust. this is my first mustang and can't do it myself.

Thanks