Topic: 1966 Rear Backing Plates

[Pete Bush]

I know that Mustangs used two different carrier types. 6-cylinders used a four lug-bolt integral carrier, while V-8’s used a five lug-bolt removable carrier.

6-cylinder integral carriers used a 7-1/4” ring gear, and were available in conventional and limited slip drive types. Backing plates were attached to the axle and commonly accommodated 9’ x 1-1/2” brake shoes, however some convertibles have been found that used 9” x 2-1/4” brake shoes and appropriate backing plates would have been needed to accommodate this.

V-8 removable carriers used 7-3/4”, 8”, and 8-3/4” ring gears, and were available in conventional and limited slip drive types. Backing plates were attached to the axle and commonly accommodated 10” x 1-3/4” brake shoes, however GT-350’s used 2-1/2” brake shoes and appropriate backing plates would have been needed to accommodate this.

Then there were Kelsey Hayes and Bendix backing plates.

I'm doing some research and need to know what backing plate would have been used under what circumstances? In other words: How many different backing plates were there for the 66 model year?

[CharlesTurner]

Have not studied '66, but I found that in '65 there were 2 versions of front and rears between Kelsey Hayes and Bendix plates... meaning 4 different types for each location.

Starting sometime in mid '65 the metal knock-out tabs were introduced into production.  The numbers on the backing plates changed at this time.  I have samples of each and the only difference was that the later one had a "nub" in the adjustment hole area.

[Pete Bush]

Brake shoe size options appear to be the same for both years.

Suppose for discussion sake we have a backing plate that fits the 9" brakes and one that fits the 10".

Does that mean that say, Bendix did the smaller 6-cylinder and V-8 shoes, while Kelsey Hayes did the larger versions.

Four shoe sizes and four backing plate options.

Or are we saying that each manufacturer could provide shoes for each application, and therefore we need 8 backing plate options?

[Pete Bush]

Suppose we have an A-Code car, and opt to order disc brakes for the front, does that trigger a different rear brake and backing plate combo than what might ordinarily be standard?

[CharlesTurner]

Suppose we have an A-Code car, and opt to order disc brakes for the front, does that trigger a different rear brake and backing plate combo than what might ordinarily be standard?

The brakes most likely came assembled on the backing plates from either Bendix or KH.  The '65 K convertible I just finished has drum brakes all around.  The front brakes are Bendix, the rears are KH.  Have examples of '65 cars with KH disc brakes on the front and Bendix rear drums.  Based on what I have seen, the brands were used interchangeably.

[Pete Bush]

Charles,

Attached are two pictures of standard 6-cylinder backing plates; 2-1/4" front and 1-1/2" rear.

Some 6-cylinder convertibles have been found to have 2-1/4" rear brakes. I don't know the reason. But if they did, then a different set of rear backing plates would be needed to accommodate them. I'm not sure if they were Bendix or Kelsey Hayes, or both.