The rear pinion seal on my truck is leaking pretty bad. Will it be ok as long as I'm not using 4 wheel drive or do I need to get it fixed asap?

Using 4wheel drive will not hurt a thing. I would pop the fill plug off(its rubber) the back of the diff cover and see if the oil is low from time to time. You should be able to stick your finger in the hole and touch the oil without putting your finger all the way down and in .

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if it does not make a puddle when you park it but just a little drop or just a wet diff then i would just keep an eye on it
and fill as needed
if it is just a wet diff than dont worry at all because i have never seen a chrystler or a dana diff stay dry for mor than 2 or 3 years

Not the differential I mean the rear seal on the transfer case.

still the same answer if it aint a puddle then its ok to be a little wet

What he said.

_________________
LOST KJ'S
Where are you going???
Current Jeep: 2004 Jeep Liberty
-Atlantic Blue
-Air Ride Rear Suspension ; OME/Rustys Lift ; Powertrax Locker ; Moog Lower Ball-Joints ; 245/70/16 Yokohama Geolander A/T-S's on MOABS ; Flowmaster 50 SUV
Lost #007082
http://www.cardomain.com/id/jeepjeepster