i have a 99 5.4 lariat. My rear diff is slowly leaking so i need to replace the gasket and i figured while im at it i should get a new cover to but i have no clue what axle i have, on the inside of the door it says H9 but that does not come up as an option on all the sites that are selling them. IT has 12 blots. Also im looking at the covers at they go from $20-$230 im guessing the $20 ones are crap and i dont want to spend $300 lol so is a $100 one good or no?

 

Ford 9.75", and it doesn't use a gasket - it uses RTV. H9 means it's a 3.55 limited slip, 75W-140 full synthetic fluid required, and with the LS you need a 4 oz bottle of friction modifier from the dealer.

If you replace the cover, get a Mag-Hytec.

 

What's rtv and i was trying to advoid getting a mag-hytec because they were so expensive

 

This>>> http://www.permatex.com/products/aut...sket_Maker.htm

 

You're in luck then because the stock one is reusable.

 

Yeah, but not that exact stuff - this is what you need:

http://www.permatex.com/products/Aut...tv_sealant.htm