WJ knuckle and unit bearing swap with custom RCV axles

[wkoehn]

Needing to upgrade steering in my 99 XJ daily driver. This is a mild overland/camping build but I want something solid and would really appreciate better brakes. I'm leaning towards a WJ knuckle swap but I have been a bit turned off by the idea of needing to drill out the WJ rotors and weld on spacers, etc... So I called up RCV and asked one of their engineers if I could get a CV axle set built with the XJ inner axle shafts and the WJ outers. He claimed this should be no problem and I could then simply use the entire WJ knuckle, unit bearing, brakes and all with no modifications. I know this isn't the cheapest route I could take, but are there any downsides here that I'm missing other than needing to move to the 5x5 bolt pattern? I haven't found any documentation in quite a bit of searching online. I don't need the strength of the RCV shafts in this application, maybe there is a cheaper stub shaft option that would accomplish the same thing? I'm aware I can reuse the XJ unit bearing and turn it down to fit the sport trac rotors, but I'd much prefer to stick with all WJ parts for ease of replacement down the road.

 

[Evan03]

You dont need to weld on the spacer. I didnt

Drilling the rotor realy isnt as scarey as it seems. The rotor isnt using the stud to center.

Use spray paint to mark xj bolt pattern on wj rotor.

Then center a small pilot drill the bext you can on the spray painted hole location's work up to stud size in 3 or 4 steps then go a drill bit over sized.
You may need to slightly wobble out a few holes or go another drill size bigger to get drilled rotor to fall over studs. The rotor is hubcentrick so the stude holes arent critical.

Wj steering is badass. Just make sure your track bar ends up parralell to draglink. Use a stinky fab or similar kit so it ends up correct

 

[wkoehn]

You dont need to weld on the spacer. I didnt

Drilling the rotor realy isnt as scarey as it seems. The rotor isnt using the stud to center.

Use spray paint to mark xj bolt pattern on wj rotor.

Then center a small pilot drill the bext you can on the spray painted hole location's work up to stud size in 3 or 4 steps then go a drill bit over sized.
You may need to slightly wobble out a few holes or go another drill size bigger to get drilled rotor to fall over studs. The rotor is hubcentrick so the stude holes arent critical.

Wj steering is badass. Just make sure your track bar ends up parralell to draglink. Use a stinky fab or similar kit so it ends up correct

Thanks for that confirmation, but I really would like to move to the 5x5 pattern as I'm planning on swapping rear axles at some point also and can easily use 5x4.5 to 5x5 spacers for now. I agree that drilling rotors isn't scary, but I'm a bit stuck on this idea of keeping consumable parts bolt on for the future.

 

[RCP Phx]

You don't even need to drill any rotors. There rotors that already have 5 on 4-3/4" pattern. Also there is no need to modify the steering/trackbar just up-grade the xj steering components, I run the Currie Corrcet Lync with my WJ set-up.

 

[XJlimitedx99]

While I can understand your desire to stick with bolt-on parts, you're gonna pay for that heavily with the custom shafts. Drilling the rotors is really no issue as the hole locations and size are non-critical.

Moving to the 5x5 bolt pattern will also incur the cost of new wheels, and either new rear axle shafts (to move to 5x5) or adapters in the rear with spacers up front to match the width.

 

[wkoehn]

Appreciate all the input, but for the sake of the argument let's imagine that I have a rear axle set up with 5x5 already and new wheels ready to go. RCV did mention something about this being the same stub shafts as they would use on a TJ? What I'm really curious here is if there is something cheaper than going with the RCV custom axle shafts if I'm determined to go this route. I'd love to stay with u-joints if some combination of inner and outer axle shafts would fix the alignment issues that come with using the WJ knuckles without a spacer.

 

[XJlimitedx99]

Appreciate all the input, but for the sake of the argument let's imagine that I have a rear axle set up with 5x5 already and new wheels ready to go. RCV did mention something about this being the same stub shafts as they would use on a TJ? What I'm really curious here is if there is something cheaper than going with the RCV custom axle shafts if I'm determined to go this route. I'd love to stay with u-joints if some combination of inner and outer axle shafts would fix the alignment issues that come with using the WJ knuckles without a spacer.

That doesn't really make sense because the TJ and XJ use the same RCV part number. He probably meant to say WJ stub shafts.

Unfortunately the WJ shafts use CV style joints, so you cannot mix factory WJ stubs with XJ inners. I am unaware of any other stub shafts that will work.

 

[Goose_XJ88]

I thought the WJ unit bearings had the same spline count and fit on the XJ shaft.
I recall a few people doing autocross jeeps that (I thought) bolted a WJ bearing up without a spacer and ran with it. Only need the spacer for an XJ bearing.

Pretty sure it was foxwar71 but unfortunately all the pics are gone in his thread and he hasn't logged in since Sept 2022.

https://naxja.org/threads/rosss-other-dumb-jeep-for-the-street.1126685/

 

[RCP Phx]

What rear axle do you have with 5x5?

 

[wkoehn]

What rear axle do you have with 5x5?

hypothetical scenario here, sorry

 

[wkoehn]

That doesn't really make sense because the TJ and XJ use the same RCV part number. He probably meant to say WJ stub shafts.

Unfortunately the WJ shafts use CV style joints, so you cannot mix factory WJ stubs with XJ inners. I am unaware of any other stub shafts that will work.

Yeah that would make sense, I see what you mean on the part numbers that helps clear that one up at least!

 

[RCP Phx]

What axle do you have, most HD axles are dual pattern drilled?

 

[wkoehn]

I thought the WJ unit bearings had the same spline count and fit on the XJ shaft.
I recall a few people doing autocross jeeps that (I thought) bolted a WJ bearing up without a spacer and ran with it. Only need the spacer for an XJ bearing.

Pretty sure it was foxwar71 but unfortunately all the pics are gone in his thread and he hasn't logged in since Sept 2022.

https://naxja.org/threads/rosss-other-dumb-jeep-for-the-street.1126685/

Yes, this is exactly what I've been trying to track down. I did find this but it seems like people are still using the spacers to get the alignment correct when keeping XJ axles with WJ unit bearings: https://naxja.org/threads/bolt-on-5x5-hubs.1157864/ I'm not against this approach, weld the spacers on once and I'd be done.

 

[wkoehn]

What axle do you have, most HD axles are dual pattern drilled?

I've got the dana 35 right now, probably swap in a 8.25 with dual pattern axle shafts or an 8.8 with spacers?

 

[Evan03]

Some if the early wjs had ujoint shafts. I dont think they are any different than tj xj shafts other than they have tone rings on them.

The wj knuckles swap to crossover steering seems to be very complicated on the internet but is actually pretty straight forward ounce your in there.

Wj knuckles, spicer wj balljoint(unsplined), spacer. And the 5x5 uniti bearings not 5x4.75xj

The patriat or something rotors are 5x4.75 and work with wj brakes. Ohhh brakes. You need wj calipers and banjo bolt for brake line. I think k i also sourced caliper mounting bolts.
Ohhh i think i used 1/4 spacers to center caliper on rotor. Unsure if this will be needed running wj rotors.

In my opionion the currie correct link steering is beefy but isnt much of a upgrade for steering angles.
Its just beefy stock xj steering. The wj is true crossover steering with better street and offroad manners.

Lol see why its so confusing

 

[wkoehn]

Some if the early wjs had ujoint shafts. I dont think they are any different than tj xj shafts other than they have tone rings on them.

The wj knuckles swap to crossover steering seems to be very complicated on the internet but is actually pretty straight forward ounce your in there.

Wj knuckles, spicer wj balljoint(unsplined), spacer. And the 5x5 uniti bearings not 5x4.75xj

The patriat or something rotors are 5x4.75 and work with wj brakes. Ohhh brakes. You need wj calipers and banjo bolt for brake line. I think k i also sourced caliper mounting bolts.
Ohhh i think i used 1/4 spacers to center caliper on rotor. Unsure if this will be needed running wj rotors.

In my opionion the currie correct link steering is beefy but isnt much of a upgrade for steering angles.
Its just beefy stock xj steering. The wj is true crossover steering with better street and offroad manners.

Lol see why its so confusing

Probably time to go pull some parts and see what fits

 

[75SV1]

I have done a WJ setup with WJ hub bearing units. The same height as 2000-01 XJ units. I do use the weld on spacer. Also, 07-08 Dodge Nitro rotors are bolt on for 5 on 4.5. I did use the spacer adapters on the rear. My rears are Ford 8.8. I did do the Yukon axles on one. Those have 4.5 and 5.5. I could drill & Tap them for 5 on 5. I don't see the need for RCVs, unless heavy wheeling. Although I do plan at some point to get some. I could see a custom set of them, so as to not need the weld on spacer. I did look into stub shafts for lengths, so as not to use the spacer. I couldn't find specs for the dimensions to figure that out.

 

[wkoehn]

I have done a WJ setup with WJ hub bearing units. The same height as 2000-01 XJ units. I do use the weld on spacer. Also, 07-08 Dodge Nitro rotors are bolt on for 5 on 4.5. I did use the spacer adapters on the rear. My rears are Ford 8.8. I did do the Yukon axles on one. Those have 4.5 and 5.5. I could drill & Tap them for 5 on 5. I don't see the need for RCVs, unless heavy wheeling. Although I do plan at some point to get some. I could see a custom set of them, so as to not need the weld on spacer. I did look into stub shafts for lengths, so as not to use the spacer. I couldn't find specs for the dimensions to figure that out.

Awesome info! My biggest priority is to keep commonly replaced parts easily available. Your method seems like the best solution I've found so far. You are using the stock XJ inner and outer axle shafts then, right? And I would need the spacers on the caliper also? I picked up WJ knuckles and calipers and ordered new WJ unit bearings, ball joints, and brake rotors/pads so I'm kinda committed at this point

 

[wkoehn]

I have done a WJ setup with WJ hub bearing units. The same height as 2000-01 XJ units. I do use the weld on spacer. Also, 07-08 Dodge Nitro rotors are bolt on for 5 on 4.5. I did use the spacer adapters on the rear. My rears are Ford 8.8. I did do the Yukon axles on one. Those have 4.5 and 5.5. I could drill & Tap them for 5 on 5. I don't see the need for RCVs, unless heavy wheeling. Although I do plan at some point to get some. I could see a custom set of them, so as to not need the weld on spacer. I did look into stub shafts for lengths, so as not to use the spacer. I couldn't find specs for the dimensions to figure that out.

I've also been looking into the stub shaft options. IRO has a set of chromoly axles for the WJ to convert to ujoints. Of course they wouldn't sell me just the stub shafts... It's easy to find CV joint axle sets for ZJ and WJ, so if these were rebuildable it might be possible to combine the outer WJ stub with the inner ZJ axle to create the poor mans version of the custom RCV shafts I quoted.

 

[75SV1]

I did use stock XJ axles shafts. Also, you will need 1/4 spacers or washers for the caliper bracket, and WJ lower ball joints. IRO sells the washers, and others. I did machine some spacers with a shaft for a set of knuckles. I haven't installed them though. Also, added adjustable steering stops, like an XJ knuckle.