97 TJ Hub & Brake Rotor Measurements?

[netpoint]

Hey guys,

New on this forum. Have been researching what brake rotors to purchase for my 97 TJ. From the great information I have read on this forum you have to measure the hub and rotors. For 97-99 TJs hub should be 1/2 inch and rotor 3 inches with rotors being composite. Anything after the split 99 year would be 3/4 inch hub and 2 3/4 rotor.

Is this correct? Because when I measure my TJ the hub is just shy of 1/2 inch and the rotor is 2 3/4 inch measuring from inside the hat. I have read that you can't mix them up otherwise you will have problems. I bought this jeep like this and have driven a couple thousands miles with no issues.

Can anyone confirm if I have it mixed up? Thanks so much!

 

[mrblaine]

Hey guys,

New on this forum. Have been researching what brake rotors to purchase for my 97 TJ. From the great information I have read on this forum you have to measure the hub and rotors. For 97-99 TJs hub should be 1/2 inch and rotor 3 inches with rotors being composite. Anything after the split 99 year would be 3/4 inch hub and 2 3/4 rotor.

Is this correct? Because when I measure my TJ the hub is just shy of 1/2 inch and the rotor is 2 3/4 inch measuring from inside the hat. I have read that you can't mix them up otherwise you will have problems. I bought this jeep like this and have driven a couple thousands miles with no issues.

Can anyone confirm if I have it mixed up? Thanks so much!

You don't want a composite rotor. They make full cast for all the TJ unit bearings. The only accurate measurement is from the inside face of the rotor hat to the top of the rotor with a straight edge laid across it.

You can run the later rotors with the early unit bearings but the outer brake pad winds up almost exactly flush with the end of the cast slider the pads rest on.

If you try to run the early taller rotors on the later unit bearings, the rotor contacts the steering knuckle.

 

[netpoint]

You don't want a composite rotor. They make full cast for all the TJ unit bearings. The only accurate measurement is from the inside face of the rotor hat to the top of the rotor with a straight edge laid across it.

You can run the later rotors with the early unit bearings but the outer brake pad winds up almost exactly flush with the end of the cast slider the pads rest on.

If you try to run the early taller rotors on the later unit bearings, the rotor contacts the steering knuckle.

Thanks mrblaine! So full cast rotors but which year brake rotors should I order?...the ones I have now measure 2 3/4 inches from the inside face of the rotor hat to the top of the rotor with a straight edge laid across it. Thanks again really appreciate it!

 

[Jerry Bransford]

The rotors and unit bearing hubs must match. Both must be mid-99 or older or mid-99 and newer.

 

[mrblaine]

Thanks mrblaine! So full cast rotors but which year brake rotors should I order?...the ones I have now measure 2 3/4 inches from the inside face of the rotor hat to the top of the rotor with a straight edge laid across it. Thanks again really appreciate it!

Post up a pic of the unit bearing face. Pic of the rotors wouldn't hurt either.

 

[netpoint]

Thanks guys. Posting pics of hub, rotor and rotor on hub. Pics aren't great...what I took last week when had the wheel off.

Are these statements accurate?....mid-99 or older TJs hub should be 1/2 inch and rotor 3 inches (inside hat). And mid-99 and newer would be 3/4 inch hub and rotor 2 3/4 inches

 

[mrblaine]

Thanks guys. Posting pics of hub, rotor and rotor on hub. Pics aren't great...what I took last week when had the wheel off.

Are these statements accurate?....mid-99 or older TJs hub should be 1/2 inch and rotor 3 inches (inside hat). And mid-99 and newer would be 3/4 inch hub and rotor 2 3/4 inches

View attachment 293000

View attachment 293001

View attachment 293002

That appears to be the later rotor on the early unitbearing.

 

[netpoint]

Thanks so much for your help!!!

 

[DaYooperTransplant]

Resurrecting this thread.
I have a 97 TJ, and if I’m understanding this correctly with a 2 3/4 rotor I would want the later 1/2” hub bearing?

What I have currently in the pictures will work, but it will put my outer brake pad almost exactly flush with the end of the cast slider the pads rest on?

So this is the correct part number for the 1/2” hub?

Timken 513084 Axle Bearing and Hub Assembly​

Thanks for the help.

 

[AndyTJSport99]

Resurrecting this thread.
I have a 97 TJ, and if I’m understanding this correctly with a 2 3/4 rotor I would want the later 1/2” hub bearing?

What I have currently in the pictures will work, but it will put my outer brake pad almost exactly flush with the end of the cast slider the pads rest on?

So this is the correct part number for the 1/2” hub?

Timken 513084 Axle Bearing and Hub Assembly​

Thanks for the help.

View attachment 304235

View attachment 304236

Having the same confusion and problem. I have the same 3/4in hub. Did you determine which rotor is correct?

 

[mrblaine]

Having the same confusion and problem. I have the same 3/4in hub. Did you determine which rotor is correct?

The 3/4"ish hub pilot height is for the later 00-06 full cast rotor. That is also the shorter overall height unit bearing. The point that tells you is the shoulder for the rotor is about 1/4" thick.

 

[AndyTJSport99]

The 3/4"ish hub pilot height is for the later 00-06 full cast rotor. That is also the shorter overall height unit bearing. The point that tells you is the shoulder for the rotor is about 1/4" thick.
View attachment 628268

Thank you! That’s super helpful. So looks like I at least have later bearings. So 2 3/4” rotor, right? Black magic shows the 3” for the early TJs so I’m going off of that.

More color - I bought it used and the previous owner replaced the rotors. Having drag and heat issues. I suspect they chose the wrong rotors.

 

[mrblaine]

Thank you! That’s super helpful. So looks like I at least have later bearings. So 2 3/4” rotor, right? Black magic shows the 3” for the early TJs so I’m going off of that.

More color - I bought it used and the previous owner replaced the rotors. Having drag and heat issues. I suspect they chose the wrong rotors.

Correct, shorter for later.

 

[AndyTJSport99]

Correct, shorter for later.

Just realized who this is lol can’t wait to try your gear! Thanks again.

 

[mrblaine]

Just realized who this is lol can’t wait to try your gear! Thanks again.

I have your email. If you are correct, the rotors are the problem. The drag is from them somewhat, but you should see the marks on the knuckle.