New, Need wheel bearing help please

Hey, just registered and can't find the search function. Anyways, I have a 1999 Cherokee and need to replace the wheel bearing assembly. My question is: How do I know if they are composite or full cast? I have found a site online that sells them and they have 2 different types.

Thanks for the help!!

If they list both for a '99 they'll likely both fit, one just costing more and 'maybe' lasting longer. I'd stick with Timken brand hubs.

Where you at in IL? I'm near St. Louis, www.sija.org .

Cool, thanks man. I live just right across the river from you, in O'fallon.

Composite or full cast? That sounds more like rotors than hub assemblies.

In any event, you'll also need a 36mm socket for the axle nut (175 ft./lbs.) and a 12 point 13mm socket for the hub bolts (3 @ 75 ft./lbs.)

Yup, cast or composite is referring to the type of brake rotor that you have. There are different hub assemblies for cast rotors and composite rotors.

Bounty Hunter said:

If they list both for a '99 they'll likely both fit, one just costing more and 'maybe' lasting longer. I'd stick with Timken brand hubs.

Where you at in IL? I'm near St. Louis, www.sija.org .

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No, they won't both fit.

The composite rotors have a thinner "hat" where the studs for the lug nuts come through. The outside surface (the "wheel mating surface) wants to be the same, so the hubs have a different offset. Hubs designed for the composite rotors will NOT work with the full cast rotors, and hubs for the full cast rotors will not work with the composite rotors.

The change from composite back to full cast was made in mid model run on 1911. The only way you can tell is to pull a wheel and look at your rotors, or call a dealer with your VIN number and have them look up which part your XJ calls for.

So will I have problems running '93 steering knuckles, rotors, and calipers on my '88 MJ with the '88 hubs?

I'm not in St. Louis, just near it on the IL side. Waterloo to be exact.

I am going to say "most likely" since I have found out the PITA way that there are AT LEAST three (3) different thickness's of brake hubs. You know, the part that gets caught between the hub and the wheel. The rotors from '84-86 are one set, the '87-90 are another, and the '91-to not sure, are completely different in center thickness, with each set getting thinner. Here is a BIG clue to tell if you will have trouble- put the rotor on then, mount your tire. If the tire has MORE drag to it than before, if you turn it by hand, then the rotor is the wrong one. Trust me on this. Since this happpened, the guys at all the parts houses in town now know almost as much about the brakes on the XJ/MJ as the rest of us that actually own one do. Hope this helps, Ren

I ran into this in the spring, but I was doing alot of front brake work, so I just bought new cast rotors and the bearing assemblies that were compatible with cast. I don't know if that would be a solution for you or not, good luck.

A "cast" rotor is cast all of a single piece. There will be no change in material between the disc and the hat (the centre part, where the hub goes.)

A "composite" rotor has a cast disc and a wrought and machined centre section, and careful observation will show that the "hat" is pressed into the rotor disc - and the surface texture of the hat and the edge of the rotor disc will have visibly different textures

I believe that all the cast rotors are the same size, but there are two different hat sizes for composites. Measure the distance from the table surface to the bottom (inside) of the hat and to the top (outside) of the hat, and so label them on your notepad. Take that with you when you go to get rotors.

It is possible to change hub assemblies, but they're a little spendy. If you anticipate doing a lot of brake overhauls for whatever reason, it's probably not a bad idea - as I recall, the cast rotors cost rather less than the composites (less labour, less machining, no stamping and fitting of the hat, ...)

5-90

You need to get the right ones for the Job. '99 model year should have cast rotors, take a wheel off and look at the face of the rotor the wheel bolts to. If it looks like the rotor is machined out of one piece of metal, the face is about 1/4" thick, and the edge of the face is nice and square, it's a cast rotor. If it has a rough finish, a very thin face thickness and an obviously radiused edge, it's a compsite rotor.
Part # 53007449 is for compsite rotor pre '99
Part # 53007449AC is for cast rotor '00 on.

Check out this thread, the guy here has just bought '99 hubs for his '97. maybe you could hook up and help each other out with a swap.

http://www.j33p.org/board.cfm?ID=2078

Thanks for the info!!

To bring back an old thread:
I have an 88, bearings went bad.. I want to switch to the newer, stronger 99 bearings.. the rotors now rub.. I was contemplating changing the entire setup from the ball-joints out. It seems like this would work to solve the rubbing problem.. I have a donor axle so price is not an issue, but do any of you guru's now if it will work (without too much trouble.. I have a snow run in 2 weeks)
thanks,
brian