Front axle eating seals

[Seth_O]

I am in the process of installing my 3rd front axle seal on the passenger side in about 14mos. I have looked in vain, but don't see anything that is obviously causing the problem. I just find that every few months, and few hundred miles, I have a steady drip of gear oil on the inside of my wheel.

I have found only the below 2 areas that stand out as being different than I would expect: the first pic is the seal retainer; it has some obvious grooves in it but they haven't changed since I bought the truck - so whatever caused them has been fixed. The 2nd pic is my axle shaft, there appears to be an area to the right of where the axle seals that is a little rougher than the rest (circled in red.) I can barely feel some roughness to it, but I think it sits inside the sealed area.

Open to feedback on what I can do to remedy the situation as I am getting tired of replacing this thing. Tearing the knuckle all the way down looses it's novelty after the first couple of times.

 

[Tow4]

I had a pinion flange that had a scratch on the seal surface. I was going to put a speedy sleeve on it but decided to see it I could sand it smooth first. I used 800 and 1200 grit to sand it and then some metal polish to finish it up. Came out fine and hasn't leaked.

If you decide to sand it, make sure you sand all the way around so there's not a flat spot.

 

[KsM715]

That wear mark on the shaft may be just rough enough to cause your problems. I would get that polished out and see if the leak persists.

 

[gungearz]

Possible for an untrued axle shaft... Or the hub isn't perfectly trued and gives a slight unnoticed wobble. Just enough to blow a seal. Did you torque everything per the torque specifications in the TM's...?

 

[kcwell27]

Idea

Could it maybe be the axle building pressure from a blocked vent line?
And maybe that seal is the weakest link.

 

[Seth_O]

Thanks for the input all. I will sand the shaft down. I thought about a speedy sleeve, but not sure I want to go that route. I was careful to tighten to spec and in a cross-wise fashion. Good thought on the vent, now may be a good time to install the breather lines to the air intake like I've been thinking about.

 

[searls84]

I had the exact same problem with my passenger side seal going bad. Went out three times in 8 months. I replaced the axel/transmission/t-case vents with breather lines. cost about 20$ in parts if I remember correctly. That cleared my problem up! Been leak free for over a year! Also make sure you aren't over filling it with oil.

 

[Motorcar]

That seal retainer also works as a thrust collar, the opposite being the back of the hub which keeps the axle from lateral movement. Inside the hub is a bushing that looks like a kingpin bushing that keeps it from flopping around during rotation. I don't like the looks of the spot on the axle, but the seal shouldn't be riding there by it's relationship to the seal retainer...it should be riding the polished area next to the flange. But then what caused it? If all is right with end play and bushings then venting may be an issue. Just asking the question not trying to step on toes at all, the seal is being installed facing the right way? Otherwise it would wick out geal oil just from the axle shaft rotation.

 

[gringeltaube]

...... but the seal shouldn't be riding there by it's relationship to the seal retainer...it should be riding the polished area next to the flange.....

Depending on seal type and construction the seal lip could be riding as far as 17mm away from the shaft's collar; about one third in lenght of total ground area.

Edit: Also, that wear mark could have been caused at an earlier time, from an encased seal, plus sufficient vertical movement of the knuckles (= excessive play betw. kingpins and plates).

I would follow Jeff's suggestion in post #3.


G.

 

[m-35tom]

are you using new seals? by that i mean NOT new old stock which in the case of seals can be a bad idea. my money is on the vent, but that can be easily verified, don't just assume, check it.

 

[Heavysteven]

I vote clogged vent.

 

[davey8943]

Seth,

I had the exact same problem, but I saw the "rough ring" the second time I took my front axle apart.

My thoughts were exactly like Ray's above (post #2) but when I took it to a machine shop, they quickly pointed out that the splined end was much bigger than the ground surface we were thinking about sleeving!



I ultimately carefully sanded it down "a few thou" and it hasn't leaked a drop since.

Good Luck!

Dave

 

[Seth_O]

are you using new seals? by that i mean NOT new old stock which in the case of seals can be a bad idea. my money is on the vent, but that can be easily verified, don't just assume, check it.

My plan at this point is to smooth the rough area, install a new seal (ordered from Boyce last week) replace the vent with a breather line and reassemble. I really, really don't want to have to get in there again.

 

[Clay James]

Had this exact same problem. Replaced my spindle and kingpin bushings, replaced all the vents with remote breather lines and it still leaked. The last time one of the seals even fell out of the retainer. The replacement seals are all Chinese made and just suck. I gave up on them and went to a new style USA made seal that allows for some axle deflection. Custom Off-Road Equipment Been over a month and a few hundred miles and no leaks. So glad I fixed it, it was driving me nuts replacing them and having them pour gear oil after one trip.

 

[Seth_O]

Breather doesn't seem to be problematic, I could easily puff air through it from the inside once removed.

I stripped the knuckle down and found one of the thrust washers on the axle scarred up pretty good. I will likely replace it.

I have a new axle seal from Boyce in my hands, but want to double-check the orientation of it. The one I pulled out was flat/metallic side facing away from the pumpkin (so beveled metal side facing towards the vehicle ) - can some one confirm that's the correct way? Seal looked fine, and with a good axle breather I'm going to be irritated if the issue is that I installed it incorrectly in the first place. I spent probably 1-2hrs searching the web, but couldn't find anything that clearly delineated the correct orientation for the seal.

Started sanding the axle shaft today, rough area is a little worse than I thought and sanding it out is proving to be not as quick as I had hoped.

Appreciate any feedback on the seal orientation issue.

 

[gringeltaube]

No matter what type of seal you have; install it this way (see below....)

G.

 

[Seth_O]

I have always kind of struggled to get this knuckle buttoned up correctly (the outer spindle has been a bit tough to get to bolt down properly) and I just realized there are 2 thrust washers on the axle (always seemed like a part of the axle to me.) Are those side-specific? I.e. one on the inside of the u-joint and different one on the outside? The TM doesn't mention if it matters (although it is clear that the beveled side goes towards the joint,) but I had someone say to me in passing that one is thicker than the other.

 

[steve6x6x6]

Let me put it this way, you are not using locking hubs and the axle shafts are under continues duty? The bushing in the spindle is wore out and the axle shaft falls down and rubs on the steel frame of the axle seal. After removing the axle seal you will see where the axle shaft has been rubbing on it. I chuck up the axle in the lathe and polish the seal surface and install a new bushing in the spindle and seal. Have built over 200 deuce fronts.

 

[Seth_O]

I took the flap disc to the rough axle thrust washer and seal retainer. Ultimately it didn't get them as smooth as I would have liked, so after some research I ordered new take-out parts from Red River in TX. Their prices were hands-down the best I could find. I asked for good take-out, and received NOS. Some pic's of the bits, new parts on top, old on bottom.

 

[Seth_O]

I also took Steve's advice and punched out the spindle bushing and installed new.