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The knuckle mounting surface to disc mounting surface is only part of the choice on unit bearings. You have to also consider the centerline of the ball joints to the centerline of the u joint. If the u joint isn't centered when you turn the knuckle the axle shaft will move front to back inside of the axle tube. That means the splined part of the axle shaft will eventually wear or the splined part of the carrier will wear. Also the axle shaft seals can start leaking.
Ok follow me on this one.
The center line of the ball joints is fixed by the U-bracket of the axle housing and short of cutting and welding doesn't change.
The center line of the U-joint is logically set by the length of the axle and all things being equal the relationship of the two center lines doesn't change but hold phone a minute batman.
The axle is only fixed at the spindle nut and the carrier end floats as it must. Otherwise you would have binding as the knuckle rotates.
The distance from the seat of the spindle nut to the inside face of the unit bearing is as noted above is the same in all the unit bearings mentioned above so the only variable that could affect the center line you mention is the spacer behind the unit bearing.
If you were to attempt to bolt up the WJ conversion without the spacer the inside face of the bearing would bottom out on the bottom of the axle splines on both ends and you would exert extreme force getting the unit bearing mating surface flush with the knuckle. End result the axle wouldn't turn. Trust me I tested this.
If on the other hand you made your own spacer that was say way over a quarter inch then when bolted up the axle would in fact float out changing the center line you mention and cause binding.
Assuming any of the unit bearings above and the proper spacer the relationship of the two center lines doesn't change only the need for the caliper bracket.
Another suggestion I had seen was to use the WJ axle. That's a non starter as the WJ is a different wheel base.
The center line of the ball joints is fixed by the U-bracket of the axle housing and short of cutting and welding doesn't change.
The center line of the U-joint is logically set by the length of the axle and all things being equal the relationship of the two center lines doesn't change but hold phone a minute batman.
The axle is only fixed at the spindle nut and the carrier end floats as it must. Otherwise you would have binding as the knuckle rotates.
The distance from the seat of the spindle nut to the inside face of the unit bearing is as noted above is the same in all the unit bearings mentioned above so the only variable that could affect the center line you mention is the spacer behind the unit bearing.
If you were to attempt to bolt up the WJ conversion without the spacer the inside face of the bearing would bottom out on the bottom of the axle splines on both ends and you would exert extreme force getting the unit bearing mating surface flush with the knuckle. End result the axle wouldn't turn. Trust me I tested this.
If on the other hand you made your own spacer that was say way over a quarter inch then when bolted up the axle would in fact float out changing the center line you mention and cause binding.
Assuming any of the unit bearings above and the proper spacer the relationship of the two center lines doesn't change only the need for the caliper bracket.
Another suggestion I had seen was to use the WJ axle. That's a non starter as the WJ is a different wheel base.
I must have mis read where you did measure from hub flange to axle nut seat. If they are all the same then its dealers choice of space caliper or not depending on year of hub. I was/am tempted to run WJ bolt pattern to save from having to drill rotors as you said. (wheel selections seems to be bigger also). But I cant find rear axle shafts that have a 5 on 5 bolt pattern for a 8.8, or C8.25. Lastly I looked at 01 xj rotor hub hole diameter vs wj rotor hub hole and its .2mm difference. So drilling bolt pattern will be less crucial as rotor will self center.
I must have mis read where you did measure from hub flange to axle nut seat. If they are all the same then its dealers choice of space caliper or not depending on year of hub. I was/am tempted to run WJ bolt pattern to save from having to drill rotors as you said. (wheel selections seems to be bigger also). But I cant find rear axle shafts that have a 5 on 5 bolt pattern for a 8.8, or C8.25. Lastly I looked at 01 xj rotor hub hole diameter vs wj rotor hub hole and its .2mm difference. So drilling bolt pattern will be less crucial as rotor will self center.
Sorry if it wasn't clear. The hubs pretty much have to be the same in that respect as the axles are interchangeable for all those years with the exception of CAD and ABS issues.
The XJ/WJ wheels are off by more than 2mm. XJ is 5 lugs on 4.5 inches while the WJ is 5 on 5 inches. I have both and held them head to head and the studs clearly miss by more than 2mm.
I'm currently using 5 on 4.5 spacers in the back and front and plan on replacing the front spacers with 5 on 5 to 5 on 4.5 adapters to keep my stock XJ wheels with the WJ unit bearings but if you want to go with 5 on 5 wheels you could reverse it and use the 5 on 5 spacers in front and 5 on 4.5 to 5 on 5 adapters in the rear.
Sorry if it wasn't clear. The hubs pretty much have to be the same in that respect as the axles are interchangeable for all those years with the exception of CAD and ABS issues.
The XJ/WJ wheels are off by more than 2mm. XJ is 5 lugs on 4.5 inches while the WJ is 5 on 5 inches. I have both and held them head to head and the studs clearly miss by more than 2mm.
I'm currently using 5 on 4.5 spacers in the back and front and plan on replacing the front spacers with 5 on 5 to 5 on 4.5 adapters to keep my stock XJ wheels with the WJ unit bearings but if you want to go with 5 on 5 wheels you could reverse it and use the 5 on 5 spacers in front and 5 on 4.5 to 5 on 5 adapters in the rear.
I was not sure if the axles did change over threw all the years, so that's good to know. Thank You
I know the bolt pattern is different. I was saying the center hole in the rotor that slides over the hub is .2mm different. So it will be hub-centric. the rotor will not rely on the studs to center itself laterally. I have not decided which way I will go yet. Adapters is an option but I think ill stay 5 on 4.5. Easier with the 8.8 swap.
Not sure if this has been resolved or not. On mine I used WJ knuckles, terra flex spacer, 01 XJ hub, WJ brake bracket, WJ calipers (later model) and WJ rotors drilled to 5 on 4.5. No spacer was required to space the caliper and rotor properly.
Not sure if this has been resolved or not. On mine I used WJ knuckles, terra flex spacer, 01 XJ hub, WJ brake bracket, WJ calipers (later model) and WJ rotors drilled to 5 on 4.5. No spacer was required to space the caliper and rotor properly.
same setup i used, my steering looks just like that too. works great.
Not sure if this has been resolved or not. On mine I used WJ knuckles, terra flex spacer, 01 XJ hub, WJ brake bracket, WJ calipers (later model) and WJ rotors drilled to 5 on 4.5. No spacer was required to space the caliper and rotor properly.
Any issues with tie rod end and wheel clearance? What size wheels and back spacing?
Engine: 4.3L with headers and full 3" exhaust system
I used that same set up, with the addition of a track bar that will never break. With those tie rod ends, you cannot use a 15" wheel unless it has very little back spacing. The rim will hit the tie rod ends when turning.
In previous post I stated that the hubs all had the same distance from the bearing seat to the spindle nut seat was the same and that is true for all the XJ hubs I checked but I didn't check that same dimension on the WJ hub.
Looks to be a tad larger. As you can see the cotter pin will barely have wiggle room to get in. I didn't torque the spindle nut but pulled pretty hard with that breaker bar so not going to change much.
However, it all seems to work fine using the WJ hub. Everything turns smoothly with no binding or friction throughout the entire range of motion. Here it is with the WJ to XJ adapters and some test rims.
Quarter inch caliper spacers will be required with this setup. The JKS tie rod length concerned me when I first got it as I thought it was too long. In pic above The toe in is set at 1/4 inch with the drag link adjusted to center the steering wheel and there isn't but one more turn left in the tie rod before bottoming out. Full thread engagement. Yes.
Here's the track bar that I have yet to cut to length.
Next up is to fab up the track bar mount to go here.
Never mind all the rusty stuff. All just trial and error prototyping on my junker.
I'll be curious to see if you end up making the WJ unit bearings work. I'm another one running 00-01 unit bearings, WJ knuckles, redrilled rotors, 1/4" hub spacer but no caliper spacers. I don't get any binding in axle shaft u joints. I used GM TRE's like the ones UCMav posted. If he see's this, he should flip his drag link around, because the high angle TRE should be at the pitman arm, not the knuckle.
I have also done the WJ knuckle swap. Same hardware as everyone else. So much better steering and brakes.
I have 15" steel wheels. Had to do a little grinding on the off-set TRE's.
Getting ready to put on a steering stabilizer to see if it will clear up a little bump steer. My track bar is 5 1/2" shorter than my drag link. Interested in where the OP will put his bracket.
Your track bar looks a little longer. Did you fab up your owe bracket in front of the spring? How does your rig ride? any bump steer?
MH.
Originally Posted by UCMav
Not sure if this has been resolved or not. On mine I used WJ knuckles, terra flex spacer, 01 XJ hub, WJ brake bracket, WJ calipers (later model) and WJ rotors drilled to 5 on 4.5. No spacer was required to space the caliper and rotor properly.
I'll be curious to see if you end up making the WJ unit bearings work. I'm another one running 00-01 unit bearings, WJ knuckles, redrilled rotors, 1/4" hub spacer but no caliper spacers. I don't get any binding in axle shaft u joints. I used GM TRE's like the ones UCMav posted. If he see's this, he should flip his drag link around, because the high angle TRE should be at the pitman arm, not the knuckle.
To the OP, what TRE's are those? WJ?
Yes, WJ TREs. Using the goforitoffroad inserts.
I tried the drag link the other way and it just seemed wonky. Are you saying I should reverse or UCMav?
I have also done the WJ knuckle swap. Same hardware as everyone else. So much better steering and brakes.
I have 15" steel wheels. Had to do a little grinding on the off-set TRE's.
Getting ready to put on a steering stabilizer to see if it will clear up a little bump steer. My track bar is 5 1/2" shorter than my drag link. Interested in where the OP will put his bracket.
My goal is to make the track bar as close to the same length as the drag link as possible and obviously parallel. I can fab as necessary brackets at both ends. I have measurement and am going to cut the tube for the track bar to match length of DL and tack the ends on this weekend. At that point I'll see what fits where and report back.
11-17-2017, 09:18 AM
