Fellow FTE members. I'm in need of some advice. First a bit of background about my situation.

I have a 79 F-150 4x4 that has been lifted with a 3 inch suspension lift and a 3 inch body lift with 40 inch tires. It has a ford 9 inch rear end that is leaking around the passenger side wheel seal. I have taken the truck to the shop and had the seal replaced twice so far and it is still leaking.

I do some mechanical work myself such as replace the water pump, fuel pump, breaks, steering column, drive shaft u-joint's, etc..., but I have never messed with axles front or rear before. I've just paid someone else to do those jobs.

Are there any tricks to get that real axle seal to seal? If not and it won't seal I will have to replace the whole rear axle. If I have to replace the rear axle I will be looking at upgrading both my front and rear axles. I am wanting to go with 46 inch military tires. The military tires are around $200 - $300 each vs the 42 inch civilian mud tires that are around $600 each. I figure in the long run I will save money on tires going this route and I plan on keeping the truck for many years.

If I upgrade the axles I would love to go with 2 1/2 ton Rockwell military axles but the cost of the axles and finding someone to install them and labor cost may be too rich for my blood. What would you folks recommend I do in this situation?
The cheapest route would be to replace the 9 inch rear end with another 9 inch rear end, install a bigger lift, buy 20 inch wheels that will hold the 46 inch military tires and run with that but would I need to change out the gear ratio for the bigger tires? Any advice from seasoned 4x4 vets appreciated!

 

When I replaced my axle seals on my 76, I had to have new "crush rings" pressed on the axle since they were somehow damaged. One wasn't pressed on just right & I couldn't get the passenger side to seal at all. Had the machine shop redo it, and it worked out just fine. Mine had a floating axle so removing it wasn't a big deal. May be something to look at.

 

"Crush rings" eh? Thats good to know! The shop that replaced the seal twice never mentioned anything about crush rings, but it would not surprise me if they didn't know anything about them either.

I will give a shop (different shop) another go at it and I will request they replace the crush rings as well as a new seal. Thanks Dutchman!

 

I hope it helps. I got pretty good at pulling the axle with all the issues I had with mine leaking. If I recall correctly, I was able to remove everything, replace the seal, and have everything back together in under 15 minutes.

I don't have a diagram for it, but here's an example of the part:

http://www.napaonline.com/Catalog/Re...Dp%3d3%26N%3d0

 

military tires???? you need one tons, no questions asked.

 

To be honest I am impressed that you can go 4x'ing on 40s with a 44/9" combo and you are not eating u-joints and shafts like peanuts.
Rockwells are nice but as you mentioned they are spendy.
I think I might try a kingpin Dana 60 (trussed, welded, chromoly, yada yada) and a one ton Dana 80 or 14 bolt out back to hold those 46s up.

 

Easy things first. If the axle vent is plugged, pressure and heat will push oil past the seals. Have you removed/checked/cleaned the vent? They are often plugged.

 

^^^^ +1 I was just coming in to say the same thing. If you keep trying seals and the vent is still plugged, it will still leak.

 

I've owned the truck for the past 3 years and have not done any 4x'ing in it since I traded for it. To be honest, as much as I love the truck, I would not have traded for it had I known all that was wrong with it. The previous owner was in his early 20's and it looks like he just neglected and abused the heck out of the ol girl. I have put almost $4,000 in it since I've owned it and still have to have the transmission and engine rebuilt. (The transmission is slipping some and the engine is strong but smokes a little when you have to mash on the motor pulling up a hill)
I can't say how much problems the PO had 4x'ing in it.

Looks like I have a game plan now, thanks for the advice! I will try to get this 9 inch to seal by having the seal and crush ring replaced. I will also check on the axle vent and see if it is plugged.
I will then begin saving for a 1 ton axle swap like you mentioned above.

 

Blue and White and brian1080 are 100% in suggesting that the vent is clogged. Unless there is some obvious damage to the seal surface of the axle the most common cause of a repeating leak is that.
I don't understand why the crush sleeve was brought up. That is on the pinion and is used to achieve pinion bearing preload. It has nothing to do with sealing the wheel end of the axle.
As you described the smoking from your motor it sounds like you have some worn out valve stem seals. Leaking exhaust stem seals allow oil to get into your pipes. Then, when you hit the throttle, you heat up your exhaust pipes and burn some of the oil out causing the smoke. Replacing the valve stem seals is what I would try first.

 

The thing is about seals on rotating assemblies. They tend to wear grooves in the shaft. It will never seal again. Try gently prying the pinion seal out a 1/8 of an inch or tapping it in further. If there is a groove now the seal will be riding in "virgin" metal and should seal. The crush sleeve just sets pinion bearing preload like rogue said.

 

If there is a groove and I'm not able to move the seal forward or back that 1/8 inch is there a way to fix this groove? Could it be filled in with JB weld? How much would it cost to replace the axle shaft? I figure it would need to get me by for a year before I could replace the entire axles with 1 tons.

 

does anyone have a diagram of the axle assembly to post up? I can't remember the details (my issue occurred over 10 years ago) but the crush sleeve was absolutely involved with an outer axle seal leak. Maybe I'm incorrect in the name, but whatever it's called had to be pressed on.
Here's the link that discusses to some degree my issue:
https://www.ford-trucks.com/forums/1...g-again-2.html

 

I am sure you could speedy sleeve it, if it's available .A speedy sleeve is very thin and slides onto the wear area and is cemented in place. Restoring the shaft. It's fairly cost effective but requires disassembly. if you opt to put in one ton axles and springs, you will need the frame mounts as well since the 1 ton springs are wider than 1/2 ton. They are riveted to the frame and must be ground off and punched out. Fortunately Ford made them exactly half inch. So no reaming is required. (department of transportation requires mods to the frame like that have the holes reamed to the exact size. At least hear in Manitoba)

 

The axles in the Ford f-250s are plenty heavy enough and 4.56 or 4.10 gears are quite popular. Depending on your engine hpband torque. With 42" rubber you would likely want the 4.56 And they were pretty standard in the later 80's behaving the 6.9 diesel with the 4sp Borg Warner. Mine is posi 4.56 and I run 32 inch. Highway about 2100 rpm with a zf-5. I would buy a wrecked diesel cheap and put in those diffs. You can tell from the door code and tag on diff cover what they are.