Knuckle bearing help!

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Jul 22, 2005
SF Valley, Cali
Hello fellow mudders,

I’m in a bind! For the past day in a half I’ve been trying to install my knuckle bearing racers. I have a 97 fzj80 that I’m doing a birfield rebuild on, the only thing holding the project up is the damn racers. I’ve tried the freezer trick, they’ve been in the freezer all day. I’ve tried the torch, by heating up the axle bell housing and tapping in the frozen race, still nothing. Though I got the race part of the way, it didn’t take me all the way home. I’ve tried PB blast and still nothing.

When I did this job before I don’t recall having this much trouble installing the knuckle bearing racers.

Any thoughts? Tips or tricks?

Thank you



Go to HF and get a proper bearing and race driver set.
Oh to add, the bearings are KOYO bearings out of the SOR knuckle kit, if that makes a difference?
I have it! doesn't work, the brass seems to have a little better control while bashing it in.

Take the bearing driver kit back to HF and trade it for a 4# drill hammer. Jus gotta hit it harder!

I use brass hammer beat um in always works I've tried the race kits and always go back to the brass hammer
i start them with the race kit, but it has to be dead nuts on to start. then i tap around them with a brass drift and 1# brass hammer.
Make sure they are not in upside down... Please don't scoff.
Didn't have a single issue with the cheap HF race driver set that I bought and used. But I did need a nice sized sledge to get the full potential.
Using 3# Sledge with 12" Handle & Big boy Undies, or Tack Hammer and a Pull-up?
Measure the OD of the old ones and compare to the new ones. It's not impossible that the wrong ones got boxed in the right part numbered box. Make sure they should fit before making them fit. Perhaps consider sourcing some from the local parts store to see how the races go in, even if you don't use them in the rebuild. At least it'll be information. If they fit and the SOR ones don't, then measure the difference.
+1 to measuring the old and new to compare.
Ummm...instead of measuring anything the old race and the new race should have part numbers on them...Google that s***! Or if the old ones are KOYO then just compare numbers to the new one. As mentioned, they don't just tap have to hammer those things in! Some use a bearing race driving set, some use a block of thick UHMWPE and some just use a 2# harbor freight all brass hammer like me...I square them up, tap them in a crosswise fashion on 6 points like our lug pattern then once they're started and square I give them heavy hits. If you're worried about damaging the races put the brass hammer sideways across the top of the race and beat on the brass hammer with a bigger hammer...remember, harbor freight has a lifetime warranty on their hand tools
When I get home from work I'm going to check the OD and compare to the new KOYO's. I got one race in out of the 4 but who knows the new ones can be off slightly
Check the ball race socket and make sure you didn't put a groove in it by starting the bearing at a bad angle or something. If it looks smooth then you just need to hit harder. I was worried about denting the thin race when I hit mine in but a brass bar laid flat across seemed to work. Hammered on that.
Just remember that the ID should be slightly larger- maybe .001-.003" smaller than the OD for an interference fit. The old vs. new should be within .002" of each other. If the new is larger than .005" I'd be concerned.
you could try looking up the part number here to see if the spec is listed (somewhere around Pg90) - Ball & Roller Bearings.pdf
I used the HF race driver set myself and it worked fine, I did have the same trouble as you and I had to tap them back out and try again. While making extra sure I tapped them in evenly. That is the key to getting them in. I got mine in without doing any cooling and heating.
I just did the same job last week, Koyo races went to the same spot with bearing driver, so used a bigger hammer, that did it.
Just a simple idea to pull the bearing race in place instead of using a hammer to pound them in place. Make a puller by taking a 18 inch long 1/2X13 threaded rod, cut the rod to length as needed. Run it down through the center of the housing through both bearing bores. Then put your bearing race in place centered on the race drive, hold then in place on the threaded rod with 2, 1/2X13 nuts double nutted together. Then on top of the housing take a piece of steel, 1/2 thick by 2 inch wide, long enough to bridge the bearing bore. Drill a 1/2 inch hole in the center of the steel plate. Install the threaded rod through the steel plate, screw a 1/2 inch nut onto the threaded rod. Now you have a simple threaded puller, just start turning the top nut while holding the lower 2 nuts still. Just as a side note, make sure you use never seize on the threads, doing that will protect the threads, and make turning the nut alot easier.

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