Rear Brake Swap

[Kilian]

I've got a 75 3/4-ton 4x4 frame that I'm planning to use for a project but the rear axle, 14 bolt FF, has some tiny brake drums. I'd have to measure again but the drum OD is around 13". I've got an 87 3/4-ton 4x4 parts truck that has the JB7 heavy duty brake option. That axle is a 14 bolt SF.

Can I swap out the rear brakes from the 75 FF for the larger drum setup from the 87 SF?

I'm planning on using the JB7 MC and booster as well in the project, so will have the stopping power for the larger drums. Thanks.

 

[Blue Ox]

Somewhat. The semi has a completely different set of drums. At least on later ones that I'vre worked on the other brake components are the same, except maybe the backing plate and you'd have to get the right drums for the FF hubs.

The front calipers and pads on a JB7 are larger too.