I am looking to upgrade my rotors. I have noticed that there is a difference in the rotors depending on whether you have 4 wheel ABS or rear wheel ABS. How do I determine which I have? Thanks.

 

Look for a wire harness going to the back or bottom area of the knuckle area. This is your speed sensor. Now count 2 or 4. This should help you. Good luck.

 

If I am not mistaken your 98 XLT with drum brakes on the rear will have 2 wheel ABS. If 4 wheel ABS you will have a large box like pump under the hood near the drivers side fender with a lot of brake tubing running from it to the brake calipers and will have disc brakes on the rear. The lariat came with 4 wheel ABS.

 

Front discs are identical on all models but 4 wheel abs vehicles have an extra ring pressed into the back of the rotor for the abs sensors.... as far as I know.

I think 4 wheel abs started in 1999 models but may have been an option before that.