I have a 98 ram 1500 and I was replacing the Ujoints on the front end, when I noticed a small amount of fluid leaking on the drivers side axle. I bought a new seal, and I'm planning on replacing it this week.

I inspected the passenger side, and noticed some residue, but couldnt find any active leaking like I could on the drivers side. With 125k and 12 years of life, I thought that this residue may not be a big deal... however, if that suggests that the seal is leaking on that side too, I'll just go ahead and replace that seal too while its all torn apart!

Is some residue normal? or does this suggest both are shot?

 

Mine don't leak a drop since replacing the seals last year.
Mine didn't leak a drop until I changed the u-joints. I assume that the seals just couldn't take the axle shaft sliding over them going out then back in that one time.

Some fluid will roll over the top of the seals when you pull the axle shafts and can take a few days or a little more before it all runs out of the axle tube.

It is a good idea to scrape the axle tubes out with a home made scraper and give them a shot of brake cleaner to dry up what you couldn't pull out with the scraper so you won't think they are leaking when they aren't.

This is my scraper that I made out of a piece of sheet metal and a skinny board.

 

Have you recently changed the diff fluid? If so, if it was over-filled by a small amount, then the seals may weep a little.
If you haven't changed the diff fluid recently, then yeah it's probably the starting signs of the seals going.

 

im getting ready to do my passenger side seal. go to quad4x4.com and get the seal replacement kit, zman really seems to like it, and thats what im gonna buy too. unfortunately for the drivers side seal you have to remove the carrier

 

a quick way to evaluate the condition of the seals is to fill the front diff up to the fill plug, and then watch and wait for a few days.

if you get more leakage than you want to put up with, then you should replace the seals. if there's none, or not much, and/or it stabilizes after it leaks a little, and it doesn't puddle up or bother you - and you can remember to check/refill it as needed so you don't run out.... then leave it be.

if you do decide to replace them, and you've already reassembled everything, then you have to tear it all apart again. if its still apart - by all means, replace both seals, check cad bushings, collar, etc and you'll be good for another 10 years. you do have to remove the diff for the drivers side.

to answer your question - a good seal will not leak any.