Differential leaks inspection

[eng90]

Hey guys,

I found some minor leaks on the diferential...what is the proper way to where exactly the car is leaking from ??

 

[302 Hi Pro]

Only 5 places for possible live axle diff leaks that I can think about. In order of probability,

A: Pinion Seal
B: Axle Bearing seals (Right and Left side inspection required). That's 3 locations.
C: Vent valve, top of Left side axle tube
D: Rear inspection cover

Best to hoist the car on a lift as axle bearing seal leaks are sometimes hard to spot. But if you're finding drip spots in the center of the car on the garage floor, check the pinion seal.

Hope this helps,
302 Hi Pro

 

[blacksheep-1]

A couple of tips, first off don't panic over removing the pinion nut and seal, then trying to reset the "pinion preload" to factory spec, you won't be able to do it unless you remove the carrier, which is a lot more work. You have 2 choices, you can block the wheels and using a torque wrench to remove the nut and measure the torque to do it. Then replace the seal and nut and retorque to whatever you started out with...or, you can just rattle it off with an impact wrench, replace it and rattle it back on (don't go crazy!!) and go on your way.
When you install the new pinion seal, place a dab of aviation permatex around the outside of it where it mates to the housing for a little insurance.
With regards to the diff cover, when you remove it, place it on a flat surface and using a small hammer, pound the bolt holes flat against the the surface. This will even out the indentation created when the cover bolts are tightened down, This is not such a problem now days, but back when gaskets were used it was a must do to make the new gasket seal.

 

[RR2334]

Don't hammer the diff cover if it is aluminum. I used the Lube Locker gasket from LMR and it works very well.

 

[blacksheep-1]

You can hammer it flat, there's no other way to straighten it, just make sure it's on a flat surface.

 

[302 Hi Pro]

You can hammer it flat, there's no other way to straighten it, just make sure it's on a flat surface.

Are you thinking about the stamped steel rear differential covers when you mention hammer the edge on a flat surface?

I have a cast aluminum finned rear cover on my 12 Boss, and this method would crack the casting. Plus it's not necessary on cast covers with machined mounting surfaces.

I have successfully used this method on cars with stamped steel diff and valve covers that used gaskets, but not so much on auto trans pans.

My next rear diff cover will be CNC machined billet aluminum by Cortex Racing. Looking forward to that mod.

302 Hi Pro

 

[blacksheep-1]

I wasn't sure what he had, although it would never cross my mind to hammer on a cast cover. Run a flat file over it and check it with a straight edge maybe. But yes, tin or aluminum stamped pans need to be checked for straightness every time.
Sorry for any confusion