Front differential axle seal leaking again!!

[clfaus]

Hi everyone, first time poster at this site. A lot of you guys have helped me out over the years on the old site, so I'm hoping for a little advice here.

I have a 2005 Trailblazer and the front differential axle seal (driver's side) keeps going bad on me! I first replaced it at 105,000 miles and everything was fine for about 8,000 miles then I noticed it leaking again, so I replaced it again. Now here were are, only 5,000 miles later and it is leaking again!! Any ideas on why I keep going through these seals? Anyone else had problems with the seal failing in such a short amount of time?

When I installed it last time I made sure that it was completely flush with the differential and that it was in correctly. Any ideas would be helpful!

Thanks!

 

[strat81]

It's possible the CV shaft is damaged where the shaft contacts the seal and it is abrading the seal, eventually causing a leak.

However, I noticed an issue with mine that looked very much like a seal leak but was in fact a leak from the fill cap. I filled the front diff until it overflowed and sealed it back up. The problem with that is that I didn't have the vehicle level when I did it. The fill hole was pointed up slightly, so when I leveled the vehicle out, the fluid level was higher than the fill cap.

Solution? Leveled the vehicle during the fill operation, sucked out a tiny bit extra, and put some yellow (oil & fuel resistant) pipe dope on the fill cap threads. Wah-la! No more leak.

 

[AtlWrk]

Agreed. My first thought would be a damaged CV axle but the amount of damage needed probably should have been obvious when you had the shaft out.

Another thought:
It looked like my axle seal was leaking until I got everything torn apart and cleaned up--only to realize it was actually the pinion seal leaking. It ran down and forward coating the diff case under the axle and the frame below. Since the pinion seal is relatively hidden unless you're under the vehicle I just assumed it was coming from the axle.

 

[triz]

I had mine replaced 2x but it was probably around 75k before I had to do it again.

 

[clfaus]

Thanks for the replies. I'll check the CV axle for any damage when I replace the seal. I'll check the other things suggested as well. Probably won't be able to get into it until next weekend, but I now I know a couple of things to look for. At least I'm getting pretty good at this repair now that I've done it twice in the last year, ha ha.