Both Rear Axle Seals blew out

cadpwrdyj · Jul 8, 2009

I have a 2001 Ford f150 SuperCrew 4wd that I tow with. I was bringing the Jeep back home and at some point in my trip, both rear axle seals blew out. I had rear end dope all over the side of the truck and the jeep. I have already replaced the seals, but I am trying to figure out what caused them both to go at the same time. Checked the vent tube, its free from any obstructions and is not clogged or stopped up. Checked the bearings, there is no play in those or noise. What was left in there when I popped the cover looked just as clean as the new I put back in. The only thing I noticed was some sludge on the axle shafts toward the seal/bearing end like the axle shaft had gotten hot, but there was none in the chunk. The truck does have 137,000 miles on it, and I could understand if one starts leaking due to age, but both at the same time just concerned me that I might have a problem besides just a failing seal. I've towed with it quite a few times over the years and never a problem other than needing a diesel under the hood. Any ideas?

s10me · Jul 8, 2009

were the seals out of the housing, or still in the tubes

EOR MFG · Jul 8, 2009

Did you cross any water? Stream or creeks with the rear at operating temps?

cadpwrdyj · Jul 8, 2009

s10me said:
were the seals out of the housing, or still in the tubes

The seals were still in the housing, but the rubber and the spring on the oil side was all out of shape. Which made me think bearings, but they were fine, no whine, no slop, and no heat marks on them or the axle shaft other than normal shiny wear surface. Other than sludge about 8 inches from where the axle rides on the bearing marks toward R&P side nothing out of the ordinary to my untrained eye.

EOR MFG said:
Did you cross any water? Stream or creeks with the rear at operating temps?

Nope, the only part that wasn't asphalt was the dirt road going up to park and unload at Mountainside.

The only thing that was out of the norm, is that I-59 is rougher than most dirt roads I have been on, and the truck and trailer were bouncing pretty good for a good stretch 5 or so miles, I slowed it down, but the road was just crap. Not sure if all the bouncing might have played into it. I haven't really worked on axles that much just trying to make sure I am not missing something. Also, I am not sure what was in there, but it calls for synthetic so that's what I put back in there. Maybe coicindence or fluke? I usually find that never to be the case, but I dunno...thx