[Tech Writeup] Replacing the seals on your Dana 30

[GrimmJeeper]

This is my first writeup. I am posting it here, in the local chapter forum because i am tired of good writeups getting lost in the massive amount of new posts in the OEM and Mod-Tech sections. I would like to see a socal tech section, written up by us local guys. i know most of you guys know quite a bit about our XJs, and it would be great to have a place to keep track of it all.

Now, with that said, feel free to move this to the national tech forums if someone feels it doesnt belong here, im just trying to be a Rebel let me step off my soapbox and get to the writeup.



This is why i decided to tear into this job:



i noticed this leak about a year ago, just seeping a little bit. i never really thought much of it, just kept the fluid topped off. all of a sudden one day it started leaking heavily, so i know it was time i had to do something about it. the hardest part about this job was the fact that the seals are located inside the axle housing... so the whole front end needed to come apart. (hooray).

here is what i started with:



a tube of silicone to make the gasket for the diff cover, a couple quarts of gear oil (it takes just under 2 quarts to fill the D30), some brake cleaner to clean out the housing once it was all apart, and the carrier bearings (just in case they were bad. Napa part number BR72.) also, not pictured, the seals, Napa part #11899 (both sides take the same seal.

First, get the front axle up on jackstands, and remove the front driveshaft.



then remove the brake calipers, and support them somehow so they arent hanging fornt the brake hoses. i set mine on the lower control arms, but sometimes you need to use a coathanger or bailing wire to hang them up. pull off the rotors and set them aside. now is a good time to check your brakes and see if they need replacing. mine were fine.

now remove the bolts holding the diff cover on:



be sure to look extra cool by smoking while you do this:



use a screwdriver to pry the bottom edge of the cover away from the housing and drain the oil, or whats left of it. my leak was bad, less than half a quart came out. its helpful to leave the top cover bolt in just a few threads so the whole thing doesnt fall off and spill your oil drip pan when you pry it loose.

now that you have the cover off the easiest way to check your carrier bearings is to place a large prybar under the ring gear and try to move the carrier.



mine had no play at all. thats a good sign, i get to take the bearings back and save some money

the next step is to remove the axleshafts so we can get the carrier out. sounds easy right? this was the hardest part of the job and took us the better part of 2 hours. my jeep is 13 years old and it spent most of its life in ohio. thats right, you guessed it, the rust monster had a long time to work on my unitbearings.



start off by spraying all the bolts with PB Blaster. if you are a smart guy like me you will forget to do this the night before to make it easier on yourself. remove the 3 bolts holding the unit bearing on and give it a few good whacks with a deadblow hammer (the kind with the lead shot inside, NOT a solid hammer). if you are exremely lucky, or if your unit bearings have been off before, they will pop right out and this point and you can skip ahead. i was very much not lucky.



we even had a hard time turning the bolts loose.



sometimes tapping the ratchet with a hammer helps when pure buffness fails.



once all the bolts were out the unitbearings still would not move at all. ok, on to plan B. plan B consists of putting all the bolts back in about half way, and putting a cheapo socket on the head of the bolt that you dont want anymore. hit the socket with the hammer a few times good and hard and see of the unitbearing breaks loose at all. if not keep going from bolt to bolt, hitting the socket with the hammer until it starts to move.



this takes awhile but it works. make sure you hit the socket NOT the bolt itself. if you try to cheat and just tap the bolts you are going to ruin the threads on the bolts and possibly the threads inside the knuckle.

make sure your friends stand around and play air guitar and talk about how bad the cheap beer you brought is:

[GrimmJeeper]

once you get the unit bearing loose it will come out with the axleshaft attached, all as one piece. there is nothing holding it on but the unitbearing so dont worry just pull it out and set it aside.



once you get it out it should look like this.



you can see the surface where the unitbearing was rusted to the knuckle. get some sandpaper and clean up this surface, wipe it down good, and rub it down with some grease or anti-sieze compound. this will make life much easier if you ever have to take the axles out again.

the next step is popping the tie rod loose so you can get the carrier out. take the cotter pin out, remove the castle nut, and put it back on about 3 turns. then hit it with a hammer till it comes loose. this way you dont ruin the threads on the tie rod end buy hitting it directly with a hammer.



remove the bolts holding the carrier caps on. there should be markings stamped into the carrier caps, and the axle housing, so you know which side is which. make sure you do not mix up the caps, they are not interchangable. if yours dont have markings get a punch or a scribe and mark them and the housing. mine had a J stamped on them right side up on the pass side and horizontal on the drivers side.



at thise point the carrier should pop right out, just give it a good tug. if not you may need to pry it a bit or get ahold of a case spreader. mine came right out.



remove the carrier and set it aside, being careful to not mix up which bearing race goes on which side.take the races off and look at the bearings and the inside surface of the race. if the surfaces look rough, scratched, or pitted in any way, you need to replace them. mine were fine, so i get to save some money, and alot of time, by not replacing the bearings.



the next step is removing the old seals from the housing. the easiest way to do this is insert a piece of pipe or a broomstick in from the outside of the axle and knock them inward. they should pop right out after a few good whacks.





now take a break and go eat some lunch and work on the next jeep in the driveway.

[GrimmJeeper]

man, that was some good carne asada, now back to work.

clean the housing out as good as you can. get the brake cleaner and wash it out completely. dont forget to clean the axle tubes out. we did this by shoving a rag into the tube from the inside, then using the broom stick from before to push it all the way to the outside of the tube. do this a few times, shaking the rag off each time and shooting some brake cleaner in there. once youve got it all cleaned out wipe out the surfaces where the seals sit and it should look like this:



make sure to clean all the old silicone off the diff cover and the housing, i used a scraper and an abrasive disk mounted to a drill, the kind you clean old gaskets off with. a wire wheel on a grinder works very well too. make sure you clean all the little pieces of silicone out of the housing after this step.

rub a small amount of fresh gear oil all over the seal to make it slide in easier, and to pre lube the rubber seal surface so the axles dont tear the rubber when you put them back in. put the seal in from the inside with the horn shaped side facing towards the outside.



this part will take two people, but hey, thats why you bought so much beer right? place a 36MM socket against the seal, and slide your broomstick in from the outside of the axle tube. line the stick up on the socket...



and hit it with the hammer to seat the seal. it will take awhile of tapping and repositioning the broomstick against the socket to get it to seat completly. once you get one side in move to the other one and do the same thing. make sure the stick you are using is small enough in diameter to fit through the seal for when you need to do the other side. we had to switch to a piece of conduit pipe to get to the second side.





once you get the seals seated make sure to knock over the bottle of gear oil just past the edge of the drip board, then use brake cleaner to make the stain bigger.



clean the bearings and races for the carrier off with brake cleaner to make sure you didnt get dirt on them when you were checking the bearings, then put it back together and pop the carrier in. put the caps back on and get out the torque wrench. tourqe the cap bolts to 60ft/lbs. you really need to use the tourque wrench here, you cant get away with just making them as tight as you think they need to be. improper torque settings on these bolts will cause uneven wear on the bearings, and more problems for you down the road. do it right the first time.



slide the axle shafts back in slowly, making sure you dont tear those nice new seals you just spent all day putting in.line up the bolt holes in the rotor backing plates and the unit bearings. make sure you are putting the backing plates back on facing the correct way. if you dont get them on right the calipers won't go back on and you will have to tear it all back apart.



place a nice even bead of silicone on the diff cover and let it sit for about 30 seconds to get tacky, then pop it on and tighten it up.



put the calipers and rotors back on, put the tierod back on the knuckle and tighten the nut to pull it back into place, put a new cotter pin in it, and you're done!



refill the axle housing until oil just starts to come out of the hole, and put the plug back in. put the tires on, take it for a drive, and enjoy your leak free housing.

[lamula]

Nice writeup Grim I liked the Photos at the critical points.
I think the challenges you had,rusted parts and frozen bolts etc.,is what we all run into. I hate manuals that show things coming apart so easlly and it takes me all day.

[GrimmJeeper]

Originally Posted by lamula

Nice writeup Grim I liked the Photos at the critical points.
I think the challenges you had,rusted parts and frozen bolts etc.,is what we all run into. I hate manuals that show things coming apart so easlly and it takes me all day.

thanks, it was really great to have the guys there that knew what they were doing. i'd have been lost if i was going by the book.

[Skwerly]

SWEET man, nice work on all that posting!! I agree, a local tech forum could be very beneficial! Besides, for those who come on and go to the `newest posts` part, they'd show up anyhow as tech and not much would change maybe!

Good ideas, good job, and good post man! Now go find a job.

[Leep]

Good write up grimm. I wished that I had done the same thing when I changed my disco to a non-disco setup. It is not that hard, just knowing what to get and what to take apart to do the job.

Leep

[Gerr]

best part of a local tech section is we can share where we got our parts from locally and you know theres some one local you can ask questions to that you may have already met

[GrimmJeeper]

thanks guys, i spoke to the powers that be, and got the reply that "tech doesnt belong in the local forums" so this post will be moved soon, and no dice on a local tech forum. hopefully though we will get a sticky post linking to tech articles sometime. i just hope the sticky police dont come down on us again

[Clean Racing]

Grim. for as much as you run azuza, you should really get a set of alloy tube seals to keep some of that sand and muck from ruining your new inner seals.. Just fyi.. nice write up..

[tcm glx]

Nice job Grimm!!

[OjXj]

Very nice write up - lucky I came across it - I was noseying in the SoCal forum - got bored of mine! Man - just how many friends did you have there? - there's like a different guy in almost every pic!

So you didn't do the outer axle seals also? I guess it will be easy to do now that you've done the hard work.

Thanks

[mattyj]

Good job Grim.... nice write up with some humour! And i see you had the "A-Team" over there helping ya!

[GrimmJeeper]

Originally Posted by mattyj

And i see you had the "A-Team" over there helping ya!

oo ooo i get to be Mr. T!!!!

[scottmcneal]

nice write up.. I will need this soon...