The right rotors for my early 1999 XJ?

I've recently purchased my first Jeep and I've been going through it to fix whatever is obviously in need of fixing.

I'd like to replace the brake rotors, however there is confusion surrounding the process. Right now there are cast iron rotors on there, but I was told that anything up to mid-1999 used composite rotors. My XJ was made in February, 1999 according to the door panel sticker.

I went to the local dealer (well not really since chrysler just yanked them) and gave the parts guy my VIN to see what he could look up. He came back scratching his head saying, "well it depends..." and that's all I got out of him.

I just had to replace the U-joints on the front axle for example, and my axles seemed to match the length of the 1998 version rather than the 1999 version.

Anyway, I'm trying to figure out how to identify which rotors I'm supposed to be using for certain. Can I tell by looking at the exposed hubs or the calipers?

Thanks for any help! I'm new here, so I'll be searching around looking for other answers in the archives.

Here's why I'm confused. Napa doesn't offer composite rotors, rather they sell cast iron rotors for both types of hub that might be on the Jeep. The hubs with long lugs and the hubs with short lugs. Here's a screen shot from napaonline.com

Meanwhile, I did a lookup on the 1998 rotors available

Since there's a crosswalk on the cast rotor part numbers from 1998 to 1999 I guess I'm not so worried now. I just don't like those composite rotors since they've easily warped on my friends Ford cars.

You just need to check and match the rotor hat height.

Cool. I'll do that. The existing brakes are fine, but have a shudder. The rotors and pads have 80% of their usable material. I was just curious if maybe someone put the wrong ones on my jeep. I'll pull one off and measure its height and then based on which of the two wheel hubs I have, I can tell if the wrong one is on there.

Here's a posted I saved from a while back...Don't recall who posted though:

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I had this exact same problem on my 99 Cherokee. My rotors warped so I needed to replace them.
The problem is that in 1999 they changed the height of the disk.
I had the problem where they gave me the wrong disks also.
There are 2 rotors available for your year.(same as 99)
One has a 3 1/16 overall height and the other a 3 3/16 overall height.

I went to a place that specialized in rotors and twice the guy gave me the wrong rotors. Both times what would happen is they would bottom out and press down into the hub thus freezing the wheel.
The guy was so stubborn that he had the right part number that I asked for my money back and went elsewhere.

Lay your old disks on a flat surface. Measure the height. I bet it's 3 1/16 and that the disks they've been giving you are 3 3/16s.

By doing a search on Raybestos I found that they had the proper size disks.
I got my rotors shipped from Rockauto.com.
They are the only ones that had the part available at that time.

The Raybestos part number I is 76923 for the 3 1/16 height rotor.

The Raybestos part number is 7142 for the 3 3/16 height rotor.


Get the 76923 part number.

mine was built 5-1999 and i have cast rotors. also the hubs are rotor specific also! just fyi

Well it turns out I have the newer style (99.5 - 2001)

I just bought new rotors and will be installing them now.

Sorry to reserect a thread but is the new style the thicker?

Ok looks like the new style is the 3 1/16

Just to add to the confusion, and for the record, you should also be aware that many after-market rotors replacing the composite rotors are cast, so the presence of cast rotors in an older vehicle may be misleading.

And don't forget the recall for XJs and ZJs for their front brake rotors. I had a then-new '98 ZJ, and had just purchased my '92 XJ (mid '99), and both were recalled for disks separating from the hub. At the time, I think they were all some style of composite. I had them both done, and within a year both sets were warped badly. Nowadays, we have four XJs, '92 thru '96, and just keep a few sets of cast rotors in stock. I use a local NAPA that will surface the rotors, and will take off just what's needed, and they last a good long time.
Hit up your local dealer, and see if your vehicle has an outstanding recall for the rotors.

Quick simple question, What size/type wrenches do you need to change u-joints in a 96?

Axle u-joints? If so, a 36mm socket to remove the big nut, and 13mm, 12point socket to remove the bolts holding the hub to the knuckle. When you get the hub out, put a little anti-seize on the mating surface, to make next time a little easier.