Which rotors needed?

I read several other threads here about front rotors, but they didn't answere my question.

I'm wanting to get some new rotors for my 01 XJ, probably slotted (baer, powerslot, sp, etc), and I don't know what I need... The problem is that everything I've read on here sais that an 01 XJ should have "composite" rotors. However my measurement of the rotor comes to 3 1/6", which is supposed to be the "full cast" rotor (whereas the "composite" is supposed to be 3 3/16"). So is there another way to tell which type I have so I can make sure to get the right replacement?

Thanks, Kristoffer

You can tell by looking at the rotor... if the center hat section is thin like a piece of stamped sheetmetal then you have composite rotors... if it is thick like a cast piece then you have the full cast rotors, duh. Our '01 has full cast rotors, and they are expensive to replace.

I buy full cast rotors for my '96 from NAPA (Tru turn brand) for approx. $25 each. Matched with Ceramix brand pads for approx. $85/set it is the best stopping brake setup I've ran on an XJ.

No dust either from the ceramic pads.

HTH

Ok thanks, I didn't know that "composite" meant 2 piece. I thought it was refering to the type of metal or alloy. Mine has the "full cast" then, it's all one big hunk o junk.. the wierd thing is that it measures 3 1/16" which every app list I've seen sais is composite!

My '97 uses composite rotors, but the '87 uses full cast. The '01 uses full cast, but at a different back spacing than the early style. That makes for 3 different rotor/bearing unit designs that I know of.

While I'm at it, anyone know the size of the rear drum on the 01 so I don't have to take the wheel off and measure?

Should be either:
9 x 2 1/2"
or 10 x 1 3/4"

kristoffers said:

While I'm at it, anyone know the size of the rear drum on the 01 so I don't have to take the wheel off and measure?

Should be either:
9 x 2 1/2"
or 10 x 1 3/4"

Click to expand...

All later model XJ's use the 9" drums. Some of the earlier Dana 35s and all Dana 44s used 10" drums.

thanks!

Just replaced my 01 FULL CAST rotors after first putting the composite on not knowing.