Rear diff leaking - pinion seal

[DEERE G]

I was just about to post to ask if anyone other than me had to replace a rear pinion seal.
I have 18,000 miles on my 07' with the Chrysler 12 bolt rear. I just replaced the seal this past Tuesday. Everything looked real good as far as pinion angle and condition of things, The seal was just leaking. The fluid level was barely below the fill hole. I thought it would have been a lot lower with the amount of diff. fluid in my garage and on the rear diff.
Is this a common problem?

[Matt]

Yeah it's not hard to do... but you'll need a beam style in-lb torque wrench, the click-style won't work. Definitely want to make sure that you get the correct rotational resistance or else you can ruin the bearings/gears (too tight will damage the bearings, too loose will damage the gears due to pinion slop). So the price for the torque wrench is well worth it...

Money well spent: http://www.amazon.com/2955-Torque-Wr...1438124&sr=1-3

[Matt]

Actually... 0-60 in-lb may not be enough. That's what I would use if i was installing new gears. But for just replacing the pinion seal you'll also be turning the ring gear/carrier/axles... so you may need this one instead: http://www.amazon.com/KD-Tools-2956-...1438304&sr=1-4

[07JeepXK]

I never ended up using a torque wrench and I really didnt go by the instructions for the whole rotational resistance. Haven't had any problems since the install and that was over a year ago.

[Matt]

That sure is an expensive risk.... glad its been working out for you though. Hopefully you got lucky and got the preload correct. If you start developing a humming noise in the rear I would recommend not letting it go too long. I've seen pinion bearings seized from too much pre-load and its not pretty. And it's always the same story "yeah its been making that noise for a while, i just thought it was the tires"

Gears and bearings are something i'm extremely careful with. And I will not install them on anyones vehicles except for mine just for the simple fact that it doesn't take much to screw it up, and when you do screw it up it's not cheap.

[07JeepXK]

Yeah I hear you. My friend who gave me a hand doing it has been doing pinion seals for 10 plus years now and hasnt had any problems. He told me it will be fine. If the rear goes then i'll just install a dana 44 that comes in the 2wd HEMI XK's along with an ARB locker!

Also I put over 25,000 miles on a year along with off roading. I think it would have failed by now. Who knows.

[Matt]

Ah... well that's a completely different story! Gears are an art form.... I'm sure your friend checked the torque based on his years of experience by way of "feel". The torque method is there for guys like us who don't do gears all the time.

Its kind of like re-packing hub bearings on a vehicle... it takes some experience to learn the proper "feel" when tightening up the assembly.

I wouldn't ever advise an inexperienced person to set pinion bearing preload by feel. But someone who's very experienced is a different story.