What are the major differences. I see TJ and XJ wheel hubs are different part numbers pre and post 1999. Are the knuckles unchanged or are they also different? And yes, I know WJ knuckles are completely different from the TJ and XJ. Are there any critical measurable differences between the hubs?

 

Ok, let me ask this question in a different way. Can I use, for example only, 2002 TJ hub bearing, in a 1995 knuckle and use the 95's brake rotor and caliper?

 

The knuckles, themselves are the same 91-up. Early vs later used different hubs/rotors. If you use the TJ bearings you need to use 00-up XJ rotors to match.
There is a thread somewhere around here or naxja about the differences.

 

Apologies for not getting back to this sooner. I originally asked because on a Ford Ranger/Explorer forum, a SportTrac guy used a HP D30 setup under the front, but with 2002 TJ knuckles. And then used the unit bearing from a 2002 Explorer, to keep his ABS functional. Here is the better part. He cut the original brake mounts off the TJ knuckles, and used the rotors and calipers from the same 2002 Explorer. The caliper bracket is bolted to holes drilled in the TJ knuckles. The Explorer brakes are an inch bigger in diameter, and the calipers are 2 piston. So this should be a big improvement in braking for us as well. I want to go to the parts store and measure the TJ and Explorer unit bearing hubs side by side and see if us Jeep guys can just use existing unit bearings to fit the Explorer rotors and calipers.

The thread I pulled this from is here. I want to give this a whirl. Wife is on board for this mod too...

 

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You can see what is cut off the TJ knuckle.

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Showing the TJ knuckle with Explorer unit bearing, rotor and caliper.

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Here you can see it all mounted and ready.

This actually seems simple enough, I can probably do it myself!

 

Did you ever get this to work?

 

That is really sketchy to drill that area of the knuckle to attach a caliper. It is very thin and light duty there. I would not trust it. This is a DANGEROUS mod.

 

Agreed. Still curious how it turned out for the OP though.

 

That area couldn't be any thinner then where our orignal calipers bolt to. And those bolts are pretty small in my opinion. Pretty interested how it turned out.

 

I forgot about this due to wife's health. The guy on the Explorer Forum loves the upgrade. So it is still something I am interested. Although, the 17" DIY big brake thread here in this forum is also most intriguing...