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ZJ Ball Joint Write Up

51K views 36 replies 27 participants last post by  rcguymike 
#1 · (Edited)
Well I'm gonna finally give back to the forum after all this time of using everyone else's write ups. The ZJ's ball joints are definitely not the easiest, especially after 15 years of rust, but after you learn to do the first side the second is a breeze. This is for a D30.

First off I DO recommend doing one side at a time to use the other as a good reference. Also, go with quality ball joints, I have always used Moog chassis parts and have been very pleased.

Chock the rear tires and jack up the front end. Place jackstands under the axle far enough away from the ends of the axle so as they don't get in the way. Remove the front tires, and you should have this (minus the black dog)...



Next, you will need to remove the brake calipers and tie them up. They are removed by unbolting the two 13mm bolts on the backside of the caliper. One on the top end and one on the bottom. Here you see the one on the top end looking down...



I opted to tie the caliper up on the lower control arm to keep it out of the way...



Now the rotor will just slide right off...most of the time.



Next, I opted to remove the whole hub assembly with the axle shaft still connected. There are three 13mm, 12 point bolts on the backside of the assembly, arrayed around the axle shaft connection. These will be rusted unless your hubs have been remove recently. I had to use a 3/8" ratchet and pipe because I had misplaced my 1/2" drive 13mm. Also use a bunch of PB blaster taking these out and reinstalling them to make it easier on you.

Here are the top two bolts on the backside of the hub with the third one on the below the axle shaft connection...



This is what the bolt looks like that you're pulling out...



Now here is a really neat trick I learned from mrblaine on stu-offroad. To remove the assembly get a 3/8" bolt 2 1/2" long with a matching nut (grade 8 preferably). This will be placed between the outer axle shaft ear and the axle housing. Now with the vehicle turned on but not started, have someone else turn the steering wheel toward the outside of the hub assembly. There will be pressure while turning the wheel but keep turning until the assembly pops right out. Here is the setup...



You will know when the hub pops out because you will be able to pull straight out on it and the whole assembly should come right out (including the axle shaft). More than likely it won't pop, just give way and smoothly come out of the axle housing. Also, in pulling the hub, the rotor dust shield is released. You should be left will something like this...



Now you will need to remove the knuckle. First you need to remove the TRE attached to the steering arm. Remove the castle nut on top almost all the way but leave a few threads on. Now hit the side of the knuckle where the TRE joint goes through. After a while it will give up and fall out. You can either tie it up or let it set on the ground. It's a good idea to antiseize the taper of the joint before reinstalling to avoid headaches in the future.

Next remove the two castle nuts on the ball joints. The top is a 7/8" and the bottom is a 1-5/16". Leave the nuts on the ball joint studs a couple threads to catch the knuckle when it releases. The ABS sensor is held in with one 8mm bolt on the inside of the knuckle, you need to remove this before the knuckle. To release the knuckle it usually takes a few good whacks, straight down on the knuckle. Once it releases, remove the nuts and the knuckle completely. Now you have this...



It's time to press the existing ball joints out. I recommend a good sturdy press because of the forces being put on it and a breaker bar. Which ever way you go (rent or buy) it should come with instructions on how to use the adapters, but it is pretty straight forward. The removal adapter has a notch cut in the side so you can see what's going on and it will completely surround the bj and sit flush on the A-arm. The installation adapter won't have a notch because it will sit on the new ball joint's lip around the edge when it is pressed in. Here is the setup for the removal of the upper ball joint...



Once you have the press setup and snug, it is time to break out the breaker bar (or impact). It will take some force and the bj will probably not pop on it's own, get the press tight and then hit the top of it with the sledge or deadblow, the bj should give a little bit, then crank and hit as needed (it's not going anywhere). Keep cranking the press until it is completely out. This is what it'll look like once it begins to come out...



Now it is time for the removal of the lower ball joint. You might have to jack the axle up some more so you can get the press upside down and have room to crank it. Use the same procedure to remove the lower as you did the upper. This is the setup...



Next, the new ball joints need to go in. It never hurts to put press-in parts like bushings, ball joints, etc. in the freezer for a couple hours prior to installation. This way they will contract a bit and go in easier. Don't put the grease zerks in the ball joints until it is pressed in, so they won't get in the way of the installation adapter. Make sure to spray some WD-40, PB Blaster or use grease to lubricate the hole where the new ball joint will go.

You will need the adapter made with a bottom angle to account for the angle the ball joints are at (this will keep them going in straight), and the large press fitting that will fit right over the top of the bj and sit on the lip. If the bj looks to be going in crooked, STOP and fix the adapter so that widest part is facing outward. This is true for the top and bottom ball joints.

The bottom bj is pressed in with the same press orientation that was used for removal, with the adapter on top and the press fitting on the bottom (sorry no pic). The top is also pressed in with the same orientation that was used for removal, with the adapter on the bottom and the press fitting on the top. Like this...



You will need the breaker bar for cranking the press in the installation process. Crank it until the lip on the ball joint is flush with the A-arm surface, then simply remove the press. You should end up with two new, perfectly pressed, ball joints. Like this...



Now you need to install the grease zerks on the ball joints along with the rubber boots. Make sure to grease very well.

Now you need to install everything back in the same order it came apart, using the other side as a reference. Like the TRE, it is a good idea to antiseize the taper of the ball joint shaft to prevent the spindle from seizing in the future.

Torque the bottom castle nut to 75ft. lbs, the top castle nut to 70ft. lbs, the TRE to 35ft. lbs, the three 13mm bolts on the backside of the hub to 75ft. lbs., and the two caliper bolts to 11ft. lbs.

- Don't forget the cotter pins in the castle nuts
- Don't forget the ABS sensor on the inside of the knuckle
- When tightening the 3 12-point hub nuts down, do them evenly
- Check grease zerk to axle shaft clearance when reassembling

I recommend blowing everything off with an air compressor before you put the wheel back on, in order to remove any debris. Also, you will probably need an alignment to set your toe if there was substantial play in the old joints. I got really lucky here, I didn't have to use any heat. However, chassis parts are infamous for needing a bit of "persuasion".

And that's all there is to it. I hope this helps everyone out, and feel free to comment on anything you think I left out. :thumbsup:

Good Luck,
Seth
 
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#5 ·
good right up, but when i did mine i had to torch the bolt that hold the hub on, since they were rust welded, now that was a PITA!!
 
#6 ·
Great write-up. I will be doing mine soon and have already bought the press.

Thanks a bunch.

Jay
 
#7 ·
good write up, i went into mine blindly, first side took 2 hours second half hour. but there was so much grease an **** on mine, on the first side i tried pressing the bottom off the wrong what, so i basically jammed it in further, and broke a breaker bar in the process.
 
#9 ·
Ya, I forgot to add that too makes it alot easier.

Crank till it's tight then hit the top of the press and it should give a little bit, then crank again and hit again. Repeat as needed.:thumbsup:
 
#10 ·
OK, I have a stupid question. I presume that when you hit the top of the press, you are striking downward on the end with the hex, or on the opposite end, depending on which way the joint will be coming out, right?

Jay
 
#11 ·
You're hitting the top of the press (the side without the screw). The side that actually pushes the ball joint out.
 
#19 ·
If you get the tools from a local auto parts store like o'reilly or autozone, make sure you have the 4wd ball joint adapter. Makes life heck of a lot easier! I did this not too long ago and it took me a total of 5 hours.
 
#21 ·
Well my balljoints just arrived and I am hoping to grab a press from somewhere in the very near future. Nice write up, should help save some knuckle skin at the very least!

Thanks
 
#23 ·
Just a thought. As I don't have a balljoitn press, and trying to find one in the Middle East will be like looking for rocking horse doo doo, would I be able to use a large C clamp and some deep well sockets to the same effect? If not I will have to send it in, which is not what I want to do!

Thanks
 
#24 ·
the inner C isnt really an A-Arm but otherwise a good writeup... im just nitpicking with the A-Arm thing haha


ALSO i dont recommend hitting the bolt on the TRE to get it out unless you are replacing tie rod ends because this can damage the threads.... if you hit the side of the cast arm on the knuckle that the TRE goes into it a few times with a mini sledge it will pop out the TRE .. you can also put a nut (not a castle nut) on the threads of the TRE and hit the TRE... this way the sledge hits the nut and not the bolt and doesnt damage the threads


some balljoints i got recently that are very nice quality and a good price are XRF balljoints.. some research on the truck sites and on pirate4x4 will yield very good reviews
 
#26 ·
I agree with CLNinja never hit the stud of the TRE with a hammer like he said the best way to get it off is to leave the castle nut on the stud just a full turn or so and hit the flat spot of the steering knuckle on the side with a mini sledge. If you're good it will drop out with one hit, sometimes two or three. Then just hold the TRE up with your hand while you unscrew the castle nut off then lower it right to the ground. In my opinion this is the best, quickest, and cheapest way to remove a TRE, as using a pickle fork damages the boot and hitting the stud can damage the threads or possibly the actual tie rod end. I learned this from an experienced ASE mechanic / union carpenter that works on vintage military vehicles every day and I almost didn't believe him when he told me this til I did it myself. And for the hub I like that trick. I used an 8 ton 3 jaw puller but that involves pulling the 36mm axle nut off 1st. Also you know what works really good for penetrating oil - buy a bottle of simple green degreaser with a spray trigger, dump the simple green into an empty washer fluid jug or something to save it and fill the simple green bottle up with ATF and lacquer thinner 1:1 and shake it up. You now have a homemade penetrating oil with 2 different spray patterns on the bottle that works better than liquid wrench, pb blaster, or wd40. I've also heard of acetone instead of lacquer thinner. I used this homebrew mix tearing down a rusty old D30 from a junkyard and it worked well for me, soaked all bolts, hubs, ball joints, and u joints overnight. Actually got my hubs off just using a mini sledge without any trouble.
 
#27 ·
What ball joint press did you use?
I borrowed the OEM 27023 kit from AutoZone. None of the adapters are slotted or angled with nothing the right size to press the upper in. The separate 4WD adapter kit is for a Dana 44 and was useless. It fit the upper but was too tall to work with.
I did not disconnect the tie rod end. Just swung the steering knuckle out of the way and supported it.
Used Dana Spicer ball joints. Got these from justdifferentials.com for $110 - both sides including delivery cross country.
Thanks for the write up...
 
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