Had stealership change the diff fluid and now have a leak at the seal on the front of the rear differential.

How difficult a job is it?

Can i just add fluid to replace what comes out when we remove the old seal or do I need to drain and refill with new fluid?

My truck is a 2002 1500 with 4X4 and limited slip differntial---if I add fluid do I have to add the firciont additive or can I just add the needed amount of synthetic gear oil?

Thanks for any help --

 

Take it back to the dealer, tell the service tech that it wasn't leaking prior to them working on it and you want them to fix it. Locate your work order if the mechanic didn't state diff leak on his visual inspection they should fix it. BTW you have to drain the diff in order to pull the diff cover and replace the seal

 

Gentlemen, I have notice a increase of sh*t like this occuring more and more when vehicle are taken in for service. I am quessing times have gotten so tough that these guys are just doing whatever they can to grab a dollar. I don't like it! Rant.....

 

Are you talking about the seal around the cover or the pinion seal? Either is something that can be done yourself but if you suspect it was something that they (stealership) did then I would take it back.

 

no way they screwed up a front seal by changing the diff fluid. it might just be that you were low on fluid so didnt see it, now that they filled it up it's leaking again.

 

I was thinking that too feej but wanted to make sure he was talking about the pinion seal. Ya know "front" can be many different things to different people, lol.

 

The pinion seal is a tedious task but is not that hard. If you don't tighten up the nut precisely then you can have major failures in the differential.
You begin by marking the nut. Mark it with a scrath preferably. Both the nut and the mating surface. When you break the nut loose, you MUST count the turns it takes to unscrew it. Pay attention where the marking is when it's ready to come off on it's last turn and make a note of where it's positioned at that point as it may be a hlaf turn and that's where you'll start when you put it back on. Pry the seal out(not particularly easy with the pinion shaft sticking out but its been done many times and you'll have to work it all the way around. Put the new one in and evenly tap in all the way around. When you put the nut back on begin where you noted the nut came off and install it with the same amount of turns unti you are back the the EXACT amount of turns it took to take it off and you should be lined up with your original mark.(make sure youroriginal mark isn't made on the seal...duh..lol or the washer itsle f that can turn at any time the nuts loosened.) When you get to that point, you'll want to tighten the nut one clock position. Like from 1:00 to 2:00, no more than that!

You'll prob get fluid spilling out when you take the seal off. What i like to do is put the front up in the air and chock the rear wheels. this will put the fluid at the back cover and you won't get any leaking. plenty of room to work under there like that. You'll need to take the driveshaft off ofcourse. Just a couple of 13mm start bolts i believe???? Not to difficult but you'll wanna spray some penetrating oil on them a day prior.

Good luck. PS..I'd buy 2 seals as you may damage the first one installing it.

 

I had my leaking pinion seal changed by a "friend" that has a mobile truck repair business. He used his air gun on the pinion nut before I could stop him. I knew the threads needed to be counted and I figured he did too but I was wrong. He torgued the crap out of the nut. I have a whine in the rear end now but since I live in Missouri and he lives in Florida, I am stuck with my "friend's" work. It's been 6,000 miles since he fudged it up and it hasn't expoded yet but I wanted to go to 4.56 gears anyway. LOL.

One thing to note if you are doing the job yourself, the old nut and washer are separate pieces on the shaft. The new nut will come with a nut/washer made as one unit. Make sure you pull the old washer out before you install the new nut/washer combo. At least that's what was on the 2004 4X2 pinion seal.

 

Thanks for the replies and details--I really appreciate it. I had not seen the note about the special tightening for the nut/washer. The hint about buying an extra seal makes a lot of sense also.

BTW--it is the pinion seal that I was trying to describe.

Again--thanks for the help.

 

You MUST use the old nut/washer combo when you put it back together. No need for a new one, especially since it will change everything including how many turns it will go on and the thickness of the washers. bad idea..IMO when changing the seal. That nut should be perfectly fine for the life of the vehicle unless the threads get cooooked for some reason?

Overtightening and you have a noise, this means that your pinion cup bearings are over exerted with presure and will wear out and throw metal flakes all through out your gears. Once they nickel coating on the bearing surface is worn off, they will wear very quickly.
Also, the overtightening of the nut will change the pinion depth and that will achange the ontact pattern and raise the pattern to the top of the ring gear. That will cause wear. And you cannot just loosen that nut up now either. The crush collar has been crushed to a certain point of no return. Your SOL and the only way to fic the problem is to tear everything apart and install a new crush collar and re-spec everything.

it's not a matter of IF, but WHEN you will have failure in your rear diff. It can get bad enough to actually weld the pinion shaft to the bearing and create all kinds of havoc back there. i would not ignore your problem until you have a problem, but get it fixed as soon as you can afford to. This is why you leave experienced techs for the precision tasks.... that's fo sho.