"Pinson" Seal Home replacement or Pro?

[Some1esle]

While getting my oil changed at the local Wally World TLE, they declined the differential oil check becouse of Damaged Parts/Leaking Pinson Seal... Now they have changed the oil and did the full check the last three times.. The last one was the 20 soemthing of July, that's what 6 weeks, and just under 3K miles. Does that seal go bad that quick? Said it was "Running" Oil, I had not seen any traces of leakage from the read diff area ever... Would I be incorrect in saying that if it was "Running"/"Throwing oil up on the bottom of the truck" now that There may have been some visible seepage 2900 miles, and 6 weeks ago? I'm unsure please enlighten me.
Also, any link to replacement proceedure? I'm pretty mechanically proficient. I wrench my own bike, change breaks, water pumps, intake mods, starters, alternaters and such. Would this be a job for someone with my skill level, or should I leave it to the pros?
Thanks in advance.
Rendell

 

[fourwd1]

If your pinion seal is leaking there should be some evidence. Spray on the underside where the DS bolts on, or running down the underside of the diff. Otherwise what makes the think there is a leak? And why are you having the diff oil changed every 3K mi ?

And replacing the seal is a DYI if your handy, and so is changing the diff gear oil.

 

[Some1esle]

During the engine oil change they check all the fluids. Sorry I didn't mean to imply that I was having the Diff oil changed every 3K. what I meant to say was that as they check the oil, they check all fuild levels and lube at all the lube pionts. The guy at The Wally World Tire & Lube Express declined the differential level check since it appeared to be a bad "Pinson" seal. I added quotations around the word to show the miss spelling that he had on the service receipt. I'm not the words best speller as you may have noticed if you've read any of my posts. However, when I'm trying to write an offical document I will use spell check. Also, he even asked me when I inquired about if I knew what a "pinson" seal was.
Anyway, The origonal question was if how fast the seal would be going out? and would have had some evidence of leakage during the previous check 3k miles earlier?
Thanks for you assistance, and any further assistance or opinions would be greatly appreciated.
Peace

 

[fourwd1]

If the seal were bad/going bad it could start to leak at any time.
Have you looked at the diff to see if there is a leak, or evidence of one?

As for How-to instructions, look here

 

[Some1esle]

Yep, was leaking.... The dealer shop quoted me 1/2 hour to replace, and $7.70 for the seal. That comes out to about $50 in my book, and I can get it done while I'm at work. I have had way too much crap to do lately, and $50 to replace it sounds fair. Steve the Mech at the Dealership is a pretty straight up guy, and mostly honest as far as I can tell. He's done me right so far... So I drop it off in the morning.. I'm guessing it could go bad in a moments notice.
Thanks for the link, and had time to do it right now dowing it my self would be the trick.