TJ Dana 44 rear axle seal leak driving me crazy

I received my warranty replacement from Crown for the bearing and retainer ring, tossed the seal from the kit and am now using National 9912 seal. Roughly 100 miles since the install, including some mild offroading, and the driver side is bone dry. Thank you National!

My passenger side (which still has the Crown seal) is now showing signs of a very, very minor leak. Probably not enough for me to bother even replacing, but a nuisance nonetheless. The whole Crown kit is so cheap, you may still be better off buying it and just replacing the seal with National or something else...but I do not recommend Crown's axle seal!
 
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Bringing this back up
Havent used the TJ much lately, I bought a 2001 XJ that I did a lift and some suspension upgrades to.

Getting back to the TJ in the next week or so,

So I have measured the rear axle shaft in every manner possible, it is not bent,

I cant see the axle being bent as it was brand new, and I have not wheeled it all and it probably has 1000 miles on it tops.

I have another brand new Timken Bearing and I have a national brand seal, and the Timken brand seal.
Has anyone had better luck with one of these seals over the other ?

I used the Timken 9912S seal last time and it didnt even make it 500 miles without leaking again so I am leaning towards trying the National brand seal this time around

I know this is a common issue, but there has to be some sort of magic formula to it
or just keep changing them till the issue goes away ?
 
I wonder if re-using the four retainer nuts/bolts has anything to do with it. The FSM specifically says do not re-use. I know many people do, maybe with a little loctite, but is it possible that they don't create the same clamping force at the same torque value during reuse? I replaced the four nuts/bolts last time I did a rear axle seal a couple of years ago and it has not leaked since.
 
I wonder if re-using the four retainer nuts/bolts has anything to do with it. The FSM specifically says do not re-use. I know many people do, maybe with a little loctite, but is it possible that they don't create the same clamping force at the same torque value during reuse? I replaced the four nuts/bolts last time I did a rear axle seal a couple of years ago and it has not leaked since.
I replaced the nuts the last time I did it, but I will certainly replace the nuts and bolts this time around and keep my fingers crossed
 
My .02¢. if you buy on amazon you get screwed. I had a buddy buy brand new Timken 9912S on Amazon and the were some knock off BS that leaked right away. I happened to have a spare set of seals and bearings and the seals were way different than Amazon. The true Timken seal should have two ridges around the circumference. I'm hoping that @rasband can post some pics of the difference. The TRUE Timken seals feel beefier and heavy duty vs. Amazon crap.
 
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My .02¢. if you buy on amazon you get screwed. I had a buddy buy brand new Timken 9912S on Amazon and the were some knock off BS that leaked right away. I happened to have a spare set of seals and bearings and the seals were way different than Amazon. The true Timken seal should have two ridges around the circumference. I'm hoping that @rasband can post some pics of the difference. The TRUE Timken seals feel beefier and heavy duty vs. Amazon crap.
thats interesting

i have bought stuff on amazon before and when it shows up it was not the brand that i ordered

but the seals i ordered were in a timken box and the 9912s that i have
does look different than the national brand seal that i have

im honestly leaning towards the national brand this time because i havent used that brand

also my leak is coming from between the center of the seal and the axle shaft
NOT from around the outside of the of the seal and the differential housing
from my understanding the timken 9912s does a better job at sealing around the outside of the seal and the differential housing than the other brands

is that correct ?
 
Also it’s worth while to make sure your breather tub isn’t blocked. As the diff gets hot it needs to release pressure. If diff breather is plugged then the seal is the next area to blow out that pressure.
 
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I just replaced the seal in my son's Jeep. I used a Spicer part. Spicer 35239. I figured they probably were spicer parts to begin with. Ordered them on Amazon. They came in Spicer labeled bags.

 
I don't think that alone would cause a leak - the initial torque applied should be the same, and while overtime they may loosen up slightly, it would take much longer than 100 miles.

Anecdotally, I added brand new stover nuts when my driver side initially started to leak with the Crown seal. I re-used these nuts when I went to install the National seal, and no leak.

Given the personal experiences of no less than 3 of us on the forum, and maybe more, I can make no other conclusion than National is the brand to go with on TJ axles. I noticed on the seal's packaging, National stated something about a proprietary sealing technology. When I read this, I figured it was snake oil, but maybe there actually is something to it.
I wonder if re-using the four retainer nuts/bolts has anything to do with it. The FSM specifically says do not re-use. I know many people do, maybe with a little loctite, but is it possible that they don't create the same clamping force at the same torque value during reuse? I replaced the four nuts/bolts last time I did a rear axle seal a couple of years ago and it has not leaked since.
 
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My .02¢. if you buy on amazon you get screwed. I had a buddy buy brand new Timken 9912S on Amazon and the were some knock off BS that leaked right away. I happened to have a spare set of seals and bearings and the seals were way different than Amazon. The true Timken seal should have two ridges around the circumference. I'm hoping that @rasband can post some pics of the difference. The TRUE Timken seals feel beefier and heavy duty vs. Amazon crap.

This was so frustrating (also thank you!), here’s a side by side. The left is the garbage from Amazon, the right is from the BFH garage (I think he used summit for that order). I’m mostly moving on from Amazon, shipping speed be damned.

Mine was missing ridges you can see in the right and it was substantially lighter.

FF475C18-531F-4F8A-AEB7-70E72AC28AC9.jpeg
 
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You're using the correct retainer and it's facing the right direction. Are you axle shafts scored where the seals ride? If they are that could be the source of your leak.

If not, try smearing some RTV around on the perimeter of the seal before reinstalling it. Use a Gear Lube appropriate RTV like Mopar RTV, Permatex Gear Oil RTV, or Permatex Ultra Black. In that order.
my Dana 44 on my LJ is leaking at the axle housing (not the axle) where the seal presses in. Apparently the previous owner chipper the axle housing when he replaced the seal. Is there a fix Without replacing the entire Dana 44? I already tried getting the chipped area smooth and putting a new seal.
 
my Dana 44 on my LJ is leaking at the axle housing (not the axle) where the seal presses in. Apparently the previous owner chipper the axle housing when he replaced the seal. Is there a fix Without replacing the entire Dana 44? I already tried getting the chipped area smooth and putting a new seal.
With that damage, I'd place a bead of Permatex Gear Lube RTV or Mopar RTV onto the axle tube opening's seal seating surface for the seal to seat into and expect it to seal it.
 
So ive been going around in circles with the passenger side axle seal leaking on my TJ Dana 44 rear

Ive changed the seals out 3 times already on them

each time ive cleaned the axle area down with emery cloth
cleaned the inside of the housing
and all that good stuff
and used brand new seals

the last time I bought a totally new axle with new seal, bearings and retainer plate and i thought i had it all sealed up

the last time it was good for about 250 miles
and than i just noticed a drip coming from it this am

does anyone have any suggestions or anything to look for or do that im not doing here with this

my tj is in super nice shape
and i absolutely cant stand having vehicles that leak

definitely dont want to build another axle
i just built this one from an LJ with disc brakes, new gears, new yukon carrier and new axles.

thanks for any help
I don’t know where this thread stands but if you don’t get the right flanges and put them in correctly you’re not going to get any relief I went through the same deal
 
thats interesting

i have bought stuff on amazon before and when it shows up it was not the brand that i ordered

but the seals i ordered were in a timken box and the 9912s that i have
does look different than the national brand seal that i have

im honestly leaning towards the national brand this time because i havent used that brand

also my leak is coming from between the center of the seal and the axle shaft
NOT from around the outside of the of the seal and the differential housing
from my understanding the timken 9912s does a better job at sealing around the outside of the seal and the differential housing than the other brands

is that correct ?
Have your rear brakes been changed from drum to disk? If so are you still using the same flat axle shaft retainer bracket that came with the drum brakes? If that's the case, that's why you can't get the seal to seal. You need to replace that flat retainer bracket with the type made for disk brakes that has a raised lip around the center opening to push and keep the seal fully seated.
 
I bought a TJ with a rear axle seal leak. I did some research to redo seal myself and also had a quote from a shop. I ended up seeing some post about revolution shafts. I changed min out for the Dana 44 and no leaks since.
 
Have your rear brakes been changed from drum to disk? If so are you still using the same flat axle shaft retainer bracket that came with the drum brakes? If that's the case, that's why you can't get the seal to seal. You need to replace that flat retainer bracket with the type made for disk brakes that has a raised lip around the center opening to push and keep the seal fully seated.
Jerry and all, just for some observational input. I have a TJ Rubi with about 308k and have been suffering from this seal issue as well. I had to have the rear dif carrier bearings replaced at around 250k and replaced the original wheel bearings at the same time just because they were old. They were not leaking but one of the carrier bearings were sounding bad so I figured there would be trash in the gear oil because of that. I used Timken bearings and seals and they started leaking shortly after the install. I bought a new set of axles, bearings, seals and retainer plates just to make the change out quick and easy. I again utilized Timken Bearings and seals and they are leaking again. I had purchased another set of bearings and seals but have been putting things off until I can better determine the cause of the seal failure. I also used permatex gear oil silicone on the last install as a precaution. I have read here that the National seals seem to perform better so I bought a set just to compare. The National seals utilize a unique two piece design in the metal ring that compresses slightly to expand the rubber seal on the outside of the seal when the retainer plate is tightened. The inner seal design that seals the rotating axle also looks like a better design than the Timken. The original seals went for around 275k miles so there must be something different with the Timken that is inferior. I would sure like to see a set of original seals just to see to OEM design. I beleive they were Spicer but not sure. I would like to have one of them to compare. The Timken seals and packaging I have look legit, but the seals themselves are manufactured in Indonesia. The Nationals are Mexico so I guess that's just where we are with everything today. I'm going to install a new set of Timken bearings with the National seals and keep my fingers crossed. I am pretty confident the superior design of the National seal will cure the issue. I'll update in a few weeks after i get them changed.
 
Have your rear brakes been changed from drum to disk? If so are you still using the same flat axle shaft retainer bracket that came with the drum brakes? If that's the case, that's why you can't get the seal to seal. You need to replace that flat retainer bracket with the type made for disk brakes that has a raised lip around the center opening to push and keep the seal fully seated.
Jerry and all, just for some observational input. I have a TJ Rubi with about 308k and have been suffering from this seal issue as well. I had to have the rear dif carrier bearings replaced at around 250k and replaced the original wheel bearings at the same time just because they were old. They were not leaking but one of the carrier bearings were sounding bad so I figured there would be trash in the gear oil because of that. I used Timken bearings and seals and they started leaking shortly after the install. I bought a new set of axles, bearings, seals and retainer plates just to make the change out quick and easy. I again utilized Timken Bearings and seals and they are leaking again. I had purchased another set of bearings and seals but have been putting things off until I can better determine the cause of the seal failure. I also used permatex gear oil silicone on the last install as a precaution. I have read here that the National seals seem to perform better so I bought a set just to compare. The National seals utilize a unique two piece design in the metal ring that compresses slightly to expand the rubber seal on the outside of the seal when the retainer plate is tightened. The inner seal design that seals the rotating axle also looks like a better design than the Timken. The original seals went for around 275k miles so there must be something different with the Timken that is inferior. I would sure like to see a set of original seals just to see to OEM design. I beleive they were Spicer but not sure. I would like to have one of them to compare. The Timken seals and packaging I have look legit, but the seals themselves are manufactured in Indonesia. The Nationals are Mexico so I guess that's just where we are with everything today. I'm going to install a new set of Timken bearings with the National seals and keep my fingers crossed. I am pretty confident the superior design of the National seal will cure the issue. I'll update in a few weeks after i get them changed.