Disc Brake Conversion using 1972 Imperial Components 

by John Hertog


Imperial Homepage -> Repair -> Brakes -> John's article -> 72 Imperial

This article was copied from the 300 Club's website with permission from the club and the author.  There are many informative, technical articles on their site and we recommend that you visit them for additional information.


I parted out a '72 Imperial the other day... very rusty car with little left to save besides the drivetrain. I did peek at the front end components, more out of curiosity than anything, and I was astounded to find a disc brake setup ( spindle) that would bolt on to any Long Wheelbase Chrysler ( such as 300F or 300G ) with NO modification !

Here's two pictures of one of the spindles as it came off the car - grease, grime and all..


The next task consisted of cleaning this mess... a quick trip through the beadblast cabinet.

And the assembly, painted and detailed...

Now, we can compare the disc spindle to the drum spindle, just removed from a '60 New Yorker subframe:

As you can see, everything's the same, the size of the ball joint stud holes, their geometry and relationship with each other, the shape and length of the steering arm.... it's a DIRECT bolt-on to the upper and lower control arms and the outer tie-rod end. 

This WOULD truly have been a bolt-on, easy as pie, modification, except for ONE SMALL PROBLEM : 1972 Imperials use a 5.5"  bolt pattern for their rims and this may be different on your particular year Imperial.

As it would be kind of impractical to have to carry two spare tires around, I decided to find a suitable rotor that would fit on the Imperial spindle.  Finding a similar sized rotor with 4.5 " bolt pattern was not a problem... a 1973- to 1978 Chrysler rotor was found to be a perfect match, size-wise.

Rather, the difficulty lay in the size of the wheel bearings.  Imperials were the only Mopar cars to use A-5 inner bearings and A-3 outer bearings. Chryslers used different sized bearings that would NOT fit on the Imperial spindles. Various options were examined, and it was decided to machine the Chrysler rotors to accept the Imperial bearing races. Fortunately, there is plenty of "meat" on the Chrysler rotor's hub to machine!

The Imperial Club would like to thank John Hertog for allowing us to publish his article on our site!!

This page was last updated on November 20, 2002.  Send us your feedback, and come join the Imperial Mailing List - Online Car Club