View Full Version : Dangit! Axle Seals Blew 3K after Rebuild!

12-20-2007, 04:55 PM
The other day I noticed the lower bearing caps a little wet, but no drips. I thought maybe the grease was just oozing a little liquid out.

Today I wanted to install the fancy allen-head diff fill plug. I looked in to make sure the level was ok (.5" below opening). I stuck my finger in there and pulled out soup:eek:!

This sucks. I spent 8 hours per side, installing new everything from wheel bearings to trunion beatrings to birfs from OZ. I thought I made damn sure those axle seals were driven in square, and used all the little tricks from Romer's write-up.

Question: Since I basically just did the work 3K miles ago, I don't think I'm going to pull the knuckles off, since the trunion bearings and the wiper kit are newish. I want to pull the axle/birf assy, clean everything, install the new axle seals and leave the trunions alone. I have read that the lower trunion bearing is low rpm and won't mind the bath of synthetic oil and grease mixture, and it will eventually get grease on it anyway with gravity in mind. Sound OK?

It should take alot less time, since the wheel bearings are fresh; maybe add a little grease.

I am going to change the fluid tonight with just dino for now. I would change it every month or so to keep things fresh. I want to wait for better weather later in the winter. Any thoughts on waiting a couple months?

BTW, the inner axle shafts had some grooving on them. Probably not the best for the seals, right?

Good time to do gears right? WRONG! No money now.

12-20-2007, 05:53 PM
Well, your grooves could have contributed to the mixing.. but probably not as bad as it sounds from your description. A little wetness on the lower bolts is normal, a lot of wetness isn't. How bad was the goop inside the diff before you did the job, is it possible that grease that's causing your soup now was already in there?

I would drop the gear oil, fill with dino, drive for a while then drop the gear oil again and see if it looks better than the last time you drained it. If there's improvement, go ahead and "flush" it one more time, after more driving. You could also take off the wipers from the knuckle and inspect the area below them, to see if your felt is holding back any gear oil. Don't worry about driving a couple more months.

12-20-2007, 07:24 PM
When I regeared I left the knuckles on. Ben told me he does that to his trucks sometimes as well.

12-20-2007, 07:29 PM
The wipers are dry, at least from gear oil. There is a light film of grease on the bell. The diff oil was changed at 117K (baseline, me new owner), and at 128K during the job. It definately does not look like new mobil 1.

I am changing the fluid out tonite and will report in the am.

12-20-2007, 07:34 PM
Check your axle breathers to be sure they are allowing the axle to vent freely.

12-20-2007, 07:38 PM
I removed the breather "box" and extended the lines into the engine bay with 1/4" low-pressure fuel line.

12-20-2007, 11:14 PM
Well, I drained out dark grey gravy. Time to call Marlin in the am to "encourage" them to get those fancy axle seals made up for the 80's axles.

What is everyone using for seal drivers? I used a black piece of PVC, but I think I will have my dad turn something wooden on his lathe. Is there an SST for the seal?

12-21-2007, 08:14 AM
Yes there is an SST. I usually use a 1 x 1 square wood block or something similar, but the PVC should work fine if it's the same diameter as the inner race.

FWIW I'm tearing mine down after about 8K and would have left the knuckles on, 'cept I think I have to take them off to measure the axle tube and everything to make sure it's centered.

12-21-2007, 10:23 AM
Did you use Toyota Seals. I have heard stories on mud of people using aftermarket seals with problems. I think there was a thread a year ago where someone comnpared a NAPA to a Toyota Seal and the Toyota one was definitly better quality.

12-21-2007, 10:25 AM
Bikeman, I also use a 1.5" piece of PVC.. if you can get your dad to face the end on a lathe so it's nice and square all the better, but not critical if you're careful. Drive that thing for another month, then drop the gear oil again.. I bet it's a lot cleaner next time.

Jenny Cruiser
12-21-2007, 11:33 AM
I had a similar experience after my first job. Breathers fine, goop in the diff, but little or no diff brew in the knuckles. I flushed the mofo three times before I tore it back down to be sure it wasn't preexisting goop. I seated new seals about .5 -1 mm shy of what they are supposed to be. Playing with the seals might have helped a bit, but didn't cure the problem. Still had soupy diff.

My 94 had a weeping ps knuckle and clicking birf (records show the axles were serviced only 14K before by a non Toy shop) that was bothering me. When I tore it down there was no moly in it, just diff fluid. Seeing that I replaced both spindles and birfields with new Toy parts. I also changed how I packed the knuckle/birf. Instead of assembling the whole thing and then squirting the moly in I put it in the knuckle, birf and all before reassembly so I know exactly how much is in there. It's tricky to put everything back together (wipers and all) without making a mess, but it works for me. I only put enough moly in the knuckle to fill it to about 60% of capacity. I also offset the seals like before as well if the axle is grooved. I got the idea of putting less moly in the knuckle off of mud, but it was seeing that clean birf in my 94 that convinced me to try it. Result, no more goop in my diffs on the last three jobs. No diff fluid in the knuckles either. :thumb:

12-21-2007, 01:27 PM
Thanks for the feedback. I tried to get ahold of someone at Marlin. No go.

02-21-2008, 07:20 PM
Well an update: I replaced the seals today with factory ones. There was not much left of the grease in the knuckles. I had done 3 drain & fills. Today I seated the seals about an 1/8" shy this time. I hope it works, and if it doesn't, someone else will do it while they are installing 4.88's!

02-21-2008, 11:06 PM
I gave up. My truck's right side leaks. It leaked when it was jkimmel's axle too.
I think the knuckle isn't centered on the right side because the housing is probably bent.

I run 265,000 mile old wheel bearings. Gear oil comes out when I take off the lock-out hub's cap! Sure it isn't right, but it doesn't seem to matter that much. It has been this way for 30,000 miles. It can't be THAT wrong. Even the big rigs have conversion kits to switch old greased trailer axle bearings to run in oil. The only problem is if it ever runs out of oil.

I wouldn't sweat it. Just keep the oil level up.

02-22-2008, 08:53 AM

I know a fella who can make short work out of straightening that thing.