2006 GT 8.8" rear diff fluid capacity

[406guy]

I have a 2006 GT with the stock rear end. The cover was leaking and it was replaced by the previous owner with an aftermarket cover that has heat sink fins, a drain plug, and a fill plug. (I think this is a Ford part..previous owner said it's what comes on the Shelbys of that year)

I am going to change the rear end fluid. Any tricks or hiccups I might run into? Do the plugs have gaskets/washers I will need to replace?

Can I get away with using 2 quarts or will I need 3?

I live in a cooler climate, so I'm thinking of going with 75w-90, either the Royal Purple or Red line GL5. Both of these already have the friction modifier in them.

 

[skwerl]

Go ahead and buy 3 just to be safe. It doesn't go bad sitting on the shelf. Should have no issues with the drain and fill plugs.

 

[tjm73]

Ford calls for 4.25 pints or 2.125 quarts (2.0 litres) 75W-140 synthetic gear oil plus 4 oz friction modifier per the 2006 owners manual. It's on pages 227 & 229 with the note about the modifier on page 230.

 

[406guy]

Ford calls for 4.25 pints or 2.125 quarts (2.0 litres) 75W-140 synthetic gear oil plus 4 oz friction modifier per the 2006 owners manual. It's on pages 227 & 229 with the note about the modifier on page 230.

Checked mine and your right. The manual does call for the heavy gear lube... That's funny, I would have thought 75w-90 would have worked fine for it....

 

[tjm73]

Owner's manual has a lot of useful info it.

 

[stkjock]

Owner's manual has a lot of useful info it.

too bad so many fail to use it as a reference first.

 

[406guy]

too bad so many fail to use it as a reference first.

The owners manual is of laughable quality on this car..it feels like an old Archie and Jughead comic. But I do agree that it has much useful info and is surprisingly well written.

I looked in my Chilton's service manual, it also says to use 75W-140. I've chosen Redline synthetic, as it seems to work well in my other vehicals drivetrains.

Thanks for the info.

 

[07 Boss]

There is a plug on the drivers side. It's kinda hidden. Technically you're supposed to fill the diff until the oil comes out of this hole. It should be level with the midpoint of the axles.

When I used the royal purple with the friction modifier I found I had to add a bit anyways. I used to do 2 pts and them the 4 oz of modifier. Now that I run an Auburn I use 75-90 dino oil.

 

[tjm73]

Technically you are supposed to put 2.125 quarts in and then add the 4 oz bottle of friction modifier. That's the factory spec. But the fill till it comes out that hole also works.