know it's the front side of the rearend, but is there a specific name for the seal? Is this an expensive job to fix? I won't be dropping the driveshaft myself, as I assume that's what has to be done.

2002 F150. Took it 10k miles to start leaking something. Only seems to be doing it when parked on an incline, nose down, but the puddle in the pics accumulated after only 3 hours.

Supposed to tow 4k+ lbs of boat this weekend 100 mi roundtrip, but don't know if this is something I should run out and fix tomorrow or if it can wait until next week.

Appears to be leaking at the top. I can see where the fluid has been slung onto the gas tank. Rearend was just serviced in March of this year.

 

Rear pinion seal.

 

Yep. The important question is ....why?

Since those tend to last for ever under normal conditions.

 

Taking the drive shaft off is easy, just those 4 bolts and prop it in an ice chest, 2x4, what ever you got. Or just let it hit the ground. I didn't want to take the chance at having mine come out of the transfer case.

If you want to take it to a shop, just tell them your rear diff is leaking where the drive shaft connects to it.

If the rear end was just serviced 4-5 months ago, I would take it back to the shop and ask them what's going on. They might decide it was an error on their part and do it for free.

 

Take the plug out of the top of the diff and put your finger in there. If you can touch fluid you're fine for your trip, no worries. If you can't, buy some fluid and put some in then don't worry about it till you're ready to drop a few hundred for a shop to fix it.

 

Actually the Pinion seal is easy to replace. It may have been done half *** or it may have been a bad one out of the box.

If it were me, -

1. Check fluid level and color w/finger, just so you know.

2. Check the breather, - for it's existence, possible plugging or incorrect mounting causing possible contamination.

3. Check U-joints.

4. Check slip yoke, trans to rear end alignment ( if you can read a tape, that's easy)

5. drain and replace with PROPER fluid and new seal.

 

Just had mine fixed. I'm assuming mine started leaking due to dirt and mud. But I went ahead and changed carriers and gears while i was under there.

 

I second that motion.

 

Thanks for the guidance, guys. Got the rear pinion seal replaced today (no time to mess with it on my own, nor do I trust myself when it comes to that type of thing) for < $200.

 

Huh I always checked with an Allan wrench. Never thought about it being easier to just shove my finger in