The Stovebolt Site Forums The Parking Lot Tons 'o Fun Disc Brakes...

I have been doing a lot of reading in regards to a disc brake conversion. I went through Griggs post about using a P30 axle and have seen a couple other methods. (1948 1 Ton SRW).

Is there anything preventing using a modern disc brake rotor based on an 8-6.5 bolt pattern (mounting to original hub), buying the matching calipers, then fabricating caliper mounting plates to fit?

My ideal scenario would be to mount the caliper plate to the outside of the spindle to prevent any clearance issues with the steering components.

This would be a winter project, so I have some time before I get into it. I just want to know if there is something obvious I am missing before I buy something.

Nothing at all wrong with that approach, others have tried and some succeed.

You may need to upgrade from the old 1/2" wheel studs to the now common 9/16" wheel studs. See if the new nuts fit the old wheels though?

Grigg

I put discs on my '38. Used the original hubs. The caliper is from a 78/80 C10 and the rotor is from 78/80 K10. Mine are 6 lug. I fabricated the brackets without the small bend in them. I had to put a 1/8 inch spacer behind the bearing to make clearance.

They work fine. I recommend a large bore master cylinder bigger than 1 inch.

Two of my original rims had some bad rust on the bottoms where they sat flat… needless to say I have new wheels, and I planned to use larger studs so everything fits better. The older 2500/3500 Chevy Vans used an 8 – 6.5 bolt pattern, and it looks like the stock wheels were 16 x 6 ½. So…I am thinking everything should fit in my modern 17 x 8 wheel. I am probably going to run by Napa and measure the caliper so I can get a good idea on how it will fit relative to where I want to mount on the spindle.

Does anyone know the measurement of the hub surface to the outside surface of the spindle (where the bolt holes are), spindle thickness (at the bolt holes), and thickness of the drum between the WMS and Hub Surface? My truck is getting painted and I do not when it will be done.

Thanks for the help.

WhiteDog sent me some of his pictures (thanks), and it looks like the caliper mounting plate needs to be based off the inner side of the spindle.
Whitedog Photos

I want to stay away from the lower steering components, but I want to use more that two mounting holes in the spindle.

My idea:
Make a bracket out of 3/8" steel that will mount on three outer holes of the spindle. Make a second mounting bracket (3/8) that mounts off the two inner top holes and has the caliper mounting holes in it. Make a spacer out of plate stock, that will bolt between the two separate brackets.

I am putting to much thought into this?

It's actually a pretty good thought. It's how some of the aftermarket kits are done.

http://www.performanceonline.com/blog/2009/04/ford-9%e2%80%9d-w35-x-2-38%e2%80%9d-bearing-flange-5-x-45%e2%80%9d-5-x-475%e2%80%9d-rear-disc-brake-kit/

Well for rotors it's not bad the front rotors off a chevy 4X4 front end will work.
Drive the 1/2 inch studs out tap them 9/19.
Make the appropriate bushings and bolt them on the back of the hub.
That's the easy part.
the caliper mounting bracket is a bit trickier.
Ford 250 wheels work good.the original wheels aren't big enough to fit over the rotor and caliper.
The 51 has been on the back burner for a while so only have one bracket

I purchased the calipers for a 2010 2500 Chevy last night, so I am committed. I threw together a rough sketch of what I am thinking.

The blue identifies the plate that mounts to the outer portion of the spindle, orange is mounts to the inner, red is the spindle.

Since I do not have my truck; this is not to scale, it should be close though, and I am expecting some clearance problems.

Depending on how far back the bracket needs to be, I may try and eliminate the outside bracket; and use the bottom hole that the steering knuckle is on. It would still be the same concept, just simpler.

Caliper Mount Sketch

Good job. I may ad something similar to your "blue" bracket on mine.

BTW- You're going to have to notch the "blue" bracket to clear the axle stops.