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Ball Joint boot install question


NAXJA Forum User
Colorado Springs
I have a '91 XJ 4WD and removed upper and lower BJ with no problems. I bought TRW BJ at Advance and pressed in both with no problems either. My issue is how does one install the dust boots? The upper boot has a hard metal ring encased in rubber at both ends so it doesn't flex. The bottom one is just all rubber.

I just cannot figure out how the boots install. I'm thinking they have to attach somewhere because how does the grease stay in the joint? Can anyone give me a block of instruction??
Do the BJ have grease fittings or holes for grease fittings?

If you have grease fittings, then you would grease the BJ after you've assembled everything, including torquing down the steering knuckle.

If it DOES NOT have grease fittings or a hole to install one, then you have to follow the instructions that came with the BJ, to the letter and use any grease they supply. No instructions, no supplied grease, then use good quality grease and work it in with your fingers as you move the BJ around, build up lots of extra and put some on the inside of the boot before installing the boot.

In the past, on other vehicles, I pressed the metal ring dust boot onto the BJ with the same tool, and I used to much force and split the boot off the metal ring and it wouldn't seal.

Good luck trying to find just a dust boot, I have yet to find these as a stand alone item. Unless they are some polyurethane/rubber universal replacement, without metal rings that seal up the ends of the boot, the universals do work, but doesn't really seal well, you have to grease them often to displace any water that might work its way into the BJ.

Since then, some BJ, I was able to push the metal ring dust boot on by hand, a little difficult, but I got it on. Sometimes NOT, the ring is just too tight, I use the press tool to get it started, but DO NOT BOTTOM IT OUT, or you'll split the boot like I did, I stop short of seating it fully, then tap it on with a punch and hammer the rest of the way. Do it lightly, its delicate, it doesn't take much pressure to tear away the rubber from the ring.
Rick, does that metal ring fit into the groove in the yoke? If not I don't know what the ring is for as the BJ kit didn't come with a snap ring. All I got was the threaded insert for earlier models, grease fitting, nut and cotter pin.
Sorry confused, I have changed a dozen BJ, but never one on an XJ, well other than a track bar. So go with the advice of someone that has done the job on an XJ.

BUT, all the other BJ I've done, the metal ring is molded inside the dust boot, it fits over the edge of the BJ. There is usually some sort of cut down collar or groove for it on the end of the body of the BJ, where the stud comes out.
Thanks Rick, you are on target. Went to the parts store and with another BJ in hand I can see that the boot slides over the bottom of the BJ and it is a tight fit. Couldn't see that after the install. Then again I didn't get under it to really check as it was getting too dark to see.
Time from Time, wipe those boots clean and spray some Armour-All on them. That will keep them from drying out and coming apart before the BJ wears out.

It won't prevent them from getting the little cuts and cracks, they always seem to get, that let the greases squirt out. BUT, it does prevent them from disintegrating and/or cracking all the way around and just coming totally apart.