The Stovebolt Site Forums The Parking Lot Big Bolts 1930 1.5 ton disc brake conversion

After seeing (and reading through several pages of) the disc brake conversion/wheel threads for the AD trucks I did a search for the same for a 1930 1.5 ton and couldn't find anything. Was wondering if someone could point me in the right direction.

This will be sharing time as my semi-daily driver/work truck with my current one- a '58 1/2 ton. Initial plans are to find a later model 3/4-1 ton donor truck for 5 speed tranny, rear end, etc.

Is there a spindle that will be a simple swap or am I going to have to go with a later model front axle to get there?

From this post.
https://www.stovebolt.com/ubbthread...4-1-1-5-and-2-ton-trucks.html#Post725050

P-30... thickness of the I-beam axle end where it fits into the spindle is the same for both P-30 and 2 ton AD axles, About 3.050"...
The kingpin diameter on the 2 ton axles is 1.109", and on the P-30 it is 1.179".

What are the dimensions of these features on your axle?
Can you swap in an axle that shares these dimensions?
If so already or if you can bolt in an axle (from larger truck similar year or perhaps newer??) that accepts the P30 spindles then that is one disc brake method/option.

In my opinion chassis swap is a lot of work for usually a finished product that just looks odd. Particularly old trucks that are reasonably narrow set onto a more modern wider chassis.
Not that looks matter that much so long as you like it, but I generally like things that look as they should/did.

Thanks Grigg. I'll check those and hollar back tomorrow. Main thing is that I want to keep a straight axle in front because I want to keep the look.

To clarify I'm not doing a chassis swap. Just wanting to update the motor, trans, rear end, and brakes. At this point a 292 doesn't sound too bad to me. Something about a straight 6 in the engine compartment just sounds right.

Charlie, if you are interested, I can show you how I added disc brakes to my '38. I used a straight axle also.

I'd be very interested in seeing that Wayne. Would be a big help.
Thanks much!

Charlie, the 1st thing I acquired was a '51 Axle hub to hub. It has a larger kingpin. It also had the same width for the spring mounts. However it had 5 lug rotors on it. So I used my 38 6 lug hubs.
I used tapered bearings in the 38 hubs. I had the face of the hubs turned to make sure they would be flat.
78 to 80 Chevy K20 rotors were used with Chevy 78 to 80 C20 calipers and pads.
I fabbed caliper brackets out of 3/8 plywood to get the dimensions correct. I had the brackets cut out of 3/8 steel.
When I put it together the hubs needed a 1/8 inch spacer to make them center in the caliper.
I was running 17 inch wheels with a bead lock and they fit over the calipers without issue. I changed to 16 inch wheels and had to do some grinding on the calipers for the wheels to fit over them.

Thanks Wayne. Doesn't sound over the top. Use of the 78 to 80 K20 parts keeps it nice and available. Will surely keep this in mind as I move forward.

Hey Grigg,
Wanted to get back to you as time has flown by, but still working on other parts of the truck.

If I'm measuring correctly the front axle has the same width dimensions as an AD single axle.(49.75") so there are options there. Goal is to start taking wheels and brakes off next week so I can take some further measurements on the kingpin etc.

Thanks much.

Update:
Finally got the front end apart. After taking dims on the whole thing including the kingpins (.734), it turns out the axle in my 1.5 ton is the same as a 1/2 ton truck. Left over parts at the factory that needed to be used? Swapped out earlier in life? Who knows...

For how I'm setting this up (not needing the heavy front end components) it's a super turn of events. ECI- http://www.ecihotrodbrakes.com has a simple bolt up disc brake conversion for these. Guess I lucked out on this particular upgrade.

In all you guy's research have you found it possible to mount the rotors on the back side of the hub soas not to change the position of the wheel relative to the kingpin? I'm concerned with changing the scrub radius. If you use a kit that mounts the rotor outboard of the hub, can you use a wheel with greater negative offset to compensate?