2003 LSD - Pinion Seal Blew On Interstate - Rear Diff Ruined?

[BarryCarey]

Hey All,

Was on the interstate today and the rear pinion seal blew out. It lost a good amount of fluid, but not all of it. I can still stick my finger in the fill port and touch fluid pretty close to the top.

However, there's a pretty significant grinding at slow speeds, both straight and turning.

Is the rear end toast?

I was going to replace the seal and oil. However, if there's a good chance the rear end is toast I'll look for a replacement.

Vehicle: 2003 Explorer EB 4.6L - LSD rear end.

 

[SoHK_alumni]

Odds are, the pinion bearing is toast and that's what caused the seal to blow out. Would also account for the noise in the diff.

You might get lucky with just a new seal, bearing, race and crush sleeve, probably worth a try unless you can find a great deal on a used diff assembly.

 

[BarryCarey]

Odds are, the pinion bearing is toast and that's what caused the seal to blow out. Would also account for the noise in the diff.

You might get lucky with just a new seal, bearing, race and crush sleeve, probably worth a try unless you can find a great deal on a used diff assembly.

Thank you for the info. Can a bad pinion bearing make a substantial grinding noise? To me it sounds like gears grinding, but I'm not very familiar with diffs.