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L.Mark
11-13-2013, 02:10 PM
Quick question...I get the car back tomorrow with hopefully all the ghosts problems fixed. But my mech said I'm leaking out the differential. It had just a mild leak awhile back and it just slipped my mind with all the other more pressing stuff with the car. Is there a specific grease I should go back in with??? Thanks for any help!!!
fordmike65
11-13-2013, 02:35 PM
Grease or diff fluid? 75w-140 Motorcraft synthetic works well & recommended by FoMoCo
wannaMM
11-13-2013, 02:40 PM
Do you need the friction modifier with the fo-mo-co juice?
L.Mark
11-13-2013, 03:04 PM
Grease or diff fluid? 75w-140 Motorcraft synthetic works well & recommended by FoMoCo


My mech said take the cover off get the old grease out and put new in...I have never dealt with this so I'm flying blind and going on what he said...:). He also asked if it was a posi rear end, I thought it was limited slip???
junior
11-13-2013, 03:09 PM
I think you need to se a mechanic who knows "traction-lock" rear ends. (Any high performance Mustang shop). The diff has oil in it. preferably fomoco...what fordmike said.
fordmike65
11-13-2013, 03:10 PM
Posi~LSD. He meant diff fluid(oil). Use synthetic 75w-140. I always add a bottle of Motorcraft friction modifier. Some here say it's not needed with synth fluid, but Ford manual still states to use it, so I do. Good insurance anyway for proper LSD operation.
whitey
11-13-2013, 03:19 PM
Takes about 2.5 quarts, plus the friction modifier. You can get a gt500 diff cover and it will have a drain plug also, thats why i have one. If your going to get a gt500 diff cover you're going to need about $15 in hardware to install it....pm me if you go that route.
babbage
11-13-2013, 03:26 PM
Quick question...I get the car back tomorrow with hopefully all the ghosts problems fixed. But my mech said I'm leaking out the differential. It had just a mild leak awhile back and it just slipped my mind with all the other more pressing stuff with the car. Is there a specific grease I should go back in with??? Thanks for any help!!!


If its leaking you probably need to replace the pinon seal. I doubt its leaking from the cover mating surface. Amsoil gear oils are high quality.

What did you have fixed?
Marauderjack
11-13-2013, 03:26 PM
Posi~LSD. He meant diff fluid(oil). Use synthetic 75w-140. I always add a bottle of Motorcraft friction modifier. Some here say it's not needed with synth fluid, but Ford manual still states to use it, so I do. Good insurance anyway for proper LSD operation.


^^^^What he said^^^^ and it is not considered "grease" but fluid as stated!!:beer:
JOEMERC
11-13-2013, 05:21 PM
Tell your mechanic you want to get the 6 quarts of grease thats in the oil pan and see what he says,lol
L.Mark
11-13-2013, 08:21 PM
If its leaking you probably need to replace the pinon seal. I doubt its leaking from the cover mating surface. Amsoil gear oils are high quality.

What did you have fixed?

I had the fuel pump fixed and some wiring in the engine bay redone.
L.Mark
11-13-2013, 08:22 PM
Takes about 2.5 quarts, plus the friction modifier. You can get a gt500 diff cover and it will have a drain plug also, thats why i have one. If your going to get a gt500 diff cover you're going to need about $15 in hardware to install it....pm me if you go that route.


ohhh I like that. When the finances settle I will pm you on that...I'd also like to get a tranny pan with a drain plug...
L.Mark
11-13-2013, 08:23 PM
^^^^What he said^^^^ and it is not considered "grease" but fluid as stated!!:beer:


I could have heard wrong, he's a little gruff on the phone...either way I'll clear up what he means tomorrow morning...

Thanks for the info!!!
jaywish
11-14-2013, 06:03 AM
How many miles on the car? I ask because it may be time for new clutches. Are you near 100K? If so I would replace them while you are in there. Others will have different opinions as to when the need replacing.

Grease/oil I have heard older mechanics call it grease, no big deal. it is oil though.

Depends on how much of a leak you have if it is worth replacing the pinion seal.

You should check the axle up and down play before you even open the rear. There should not be any.
Vortech347
11-14-2013, 08:33 AM
A pinion seal takes about 20-30 minutes tops to replace. The dif cover about an hour if you give it some cure time before re-filling.

75w-140 is what you want to run.

Since there isn't a lot of gear oil in there any leak should be addressed.
L.Mark
11-14-2013, 01:21 PM
How many miles on the car? I ask because it may be time for new clutches. Are you near 100K? If so I would replace them while you are in there. Others will have different opinions as to when the need replacing.

Grease/oil I have heard older mechanics call it grease, no big deal. it is oil though.

Depends on how much of a leak you have if it is worth replacing the pinion seal.

You should check the axle up and down play before you even open the rear. There should not be any.


Talked to him today and yes he means oil but says grease. Threw me off cause he used both in the same sentence...:)...I'm only pushing 80,000 with no problems...
L.Mark
11-14-2013, 01:23 PM
A pinion seal takes about 20-30 minutes tops to replace. The dif cover about an hour if you give it some cure time before re-filling.

75w-140 is what you want to run.

Since there isn't a lot of gear oil in there any leak should be addressed.

Good call...I'm thinking without seeing it yet that its probably the seal leaking??? But we'll see.