I'm not overly mechanically inclined but today I was changing the rear diff and I noticed this. Is this a worn out bushing or something more serious? As you can see, there is spray all over the fuel tank. Also, any tips or easy way to fix this? Thanks

 

It looks like you have a slight leak in your pinion oil seal. There is no quick fix that I am aware of. It's a pretty big job to R&R that part, so just monitor the oil level in your diff more closely from now on.

 

Yep.......I can confirm with Joel_MD that it's definately the Pinion seal.
It is a big job and unless you are a skilled mech and have experience of axle rebuilds etc, leave it to the dealership or garage.
Al.

 

Pinion seal, it's another on the list of common Dodge truck problems that Chrysler has been well aware of, yet has done nothing to remedy...

 

I just replaced mine when I did the diff fluid change. I noticed my gas tank was all wet like that, so was the underside of my bed and exhaust. I wish I took pics to show you, but I just too pics of the fluid change not the pinion seal change.

You have to remove the driveshaft, remove the flange that bolts onto the driveshaft and the pinion seal is behind it. You have to make sure you retighten the big 32mm nut holding the flange the same way you remove it. If you tighten it too much or not enough you can mess with the backlash of the gears, or so I've heard.

 

10-15ft/lbs for an old crush collar like you have is what I have found out there for specs. Going the cheap easy route like you stated is not the correct way, but most garages will do it that way because nobody wants to spend $800 for one lousy oil seal repair. The reason is because the collar is suppose to be seated without the carrier inside the rear diff by the amount of rotational drag.
Now as easier way is to mark the nut and yoke. Then, count the number of turns it took to remove the nut. Replace the seal. Re-install the nut to the position in which you took it from. Tighten it a little bit (less than 1/8 of a turn) past the original markings. This is a better way to do things so to keep near the same drag as before. But the true way is to remove the entire rear diff guts and start from scratch! Of course i wouldn't go that route even if it was my own truck. i would just mark the nut, count the turns and be on my way. No actual need for torquing at that point.
The crush collar tightening is one of the most important things to do in a rear diff to keep everything harmonized.

 

Great Info. Saves a lot of time and $$$

 

oo exciting.

Thanks for the info and I'll try to figure a way to get it fixed. I'm assuming all I need to buy is just a new seal or is there more hardware that needs to be purchased also?

 

thats a great walkthrough dirty dog...i noticed that my tank is wet in the same place, although my diff housing, u-joints, and driveshaft are all spotless and dry. i know from my carfax that the truck was taken back to the dealership at very regular intervals by the previous owner, so i figured that its been fixed once...

 

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