I was out on a trail this weekend in deep mud and had my Jeep stuck. I had to lock the rear and rock it out to get free. I noticed this morning that the lower portion of the rear diff had a layer of fluid on it which seems to originate at the drive shaft entry into the diff and have a small drip. Any thoughts on what I broke?

 

does it drive fine? do you have a picture it is worth 2000 words these days?

 

Change diff fluid and let it sit for awhile with plug out. Refill and drive watch to see if leak returns. Water would have flooded area around pinion output bearing which gets lube from diff and generally small amounts of oil pool up in this area. The water would have pushed some of this oil out.

 

Stock diff covers? When I dragged my stock rear diff cover over a rock, it bent the bottom lip of the cover, which hung below the pumpkin That caused a seeping leak. Check your diff covers...they may have been damaged.

 

your looking at your pinion...pull the driveshaft off and check that your pinion nut is still 'good 'n tight' and that there is no play or slack in the pinion by giving it a good yank...obviously rotation of the pinion is fine...but anything else is a problem....but I bet all you have is bad seal...if it's not leaking too bad and it is just the seal, I'd just not worry about it and just top it up at diff lube change time

 

I am betting it's the pinion seal......I went thru a few of them......first one was messed up from my installer, seal was damaged from install of the new drive shafts.....then had another shop replace it, ended up finding out the pinion had scuff makes on it which caused the damage.....then another brand new seal installed, and failed....breaking apart to the touch, it was brittle.....then another one installed, and a speedy sleeve to ensure smooth surface to ride on.....so far so good..knock knock......