grYthshAde

I know, I know, you're thinking, "Great. Another new kid who doesn't know how to use the search bar. This damn generation..." but really, I need this question answered and I cannot, for the life of me, find out.

SO!

I have a 1999 Jeep Cherokee Classic. I need to put new hubs in, and she's due for a brake job soon anyways, so I thought I would kill three angry sparrows with one Napa bill and do those jobs, plus replace my axle U-joints while everything's open. I only have limited access to a garage, you see. So I need to buy new hubs and rotors, and I know for a fact that I have the old style composite rotors and accompanying hubs. I don't think either of those parts have ever been changed. I also know that Cast rotors are, generally, better quality than those that are composite. Bearing that in mind, this is my question--

If I change BOTH the hubs and the rotors to the new style, 1999.5-2001 Cast type hubs and rotors, will there be any problems? Or will the Jeep never even know it happened?

XJ Sam

I would assume they would be the same, but I would also wait for another member to chime and confirm.

The steering knuckles are the same regardless of hub/rotor type. So either hub will bolt directly to knuckle using the same 3 mounting points where the 12pt bolts are.

Also, regardless of hub/rotor type, the calipers are the same as well. Since everything seems to be same except the hub and rotor, I would think that as long as you match them appropriately, you shouldn't have any fitment issues.

grYthshAde

That's what I was thinking, I had called Napa and confirmed that the calipers where the same. I was just wondering if anyone else had done this previously and knew if it did or did not work.

TwoXJS

You could call NAPA again and ask if the hub part numbers are the same.

EDIT: I just looked for myself and they have two different part numbers between a '98 and 2000 hub assembly. I physically can't SEE a difference aside from a different color bearing retainer, but that's about it. Bolt patterns are most likely the same, maybe the newer ones are a bit larger or something.

superbee1970440

I believe that I read somewhere that the brake abutment brackets are different. I can't remember where I read that though.

I think that the offset of the hub is slightly different and one pushes the rotor out further, by just enough to cause a clearance issue between the rotor and the abutment bracket/knuckle.

grYthshAde

No, the hubs are different. That's why you have to match a Cast rotor with a Cast type hub and a Composite rotor with a Composite type hub.

XJ Sam

By "brake abutment bracket" I'm going out on a limb thinking you are referring to the carrier bracket for the brake caliper. If that the case, I wouldn't think that would matter since they both use the same brake caliper part number. Most decent calipers you buy with come with new carriers. If the caliper part number was the same, but the carrier was different, how would they know which carrier to include?

In my opinion, I think the rotor hat size is the only difference. One rotor probably has a larger bore, maybe a bit taller as well and it must be matched with the proper hub. The overall diameter of the hub is probably the difference between the two so you need a rotor that machined to the proper size to fit the hub. Again, only speculation, but I don't see any other brake/steering parts that differ other than the hubs and rotors.

superbee1970440

Maybe I'm wrong then.

Theres a NAXJA thread that talks about all of the rotor/hub differences. read post #3. http://naxja.org/forum/showthread.ph...e+rotor+height

XJ Sam

Read the post and it looks like it confirms what we were discussing.

The hubs themselves are what's different. Different lug stud sizes and a couple other things to accommodate the right size rotor. That hat size of the rotors have different heights to account for the proper hub assembly. According the information he posted, calipers and knuckles are the same.

So, as long as the OP matches his new hubs and rotors, he should be able to run either or. If he has composites now, he would need to buy the cast rotors and hub assembly for cast rotors. Everything else should be the same.

superbee1970440

Yeah, that's why I posted it. I guess I should have said "I'm wrong" instead of "maybe I'm wrong".

grYthshAde

Thanks guys! I'll be doing that next week then. Woo upgrades!

grYthshAde

UPDATE: It did, indeed, work to use the newer style hub with newer style rotor on a Jeep that takes the old hub/rotor assembly.

greenmtboy

Thanks a bunch for the follow-up!... I had the exact same scenario and am planning to upgrade to the cast rotor/hub combo. Glad to hear you were successful.