Stovebolt.com Forums The Parking Lot Big Bolts Disc brakes for 1.5, and 2 ton trucks

Request for careful measurements
If you have one of these trucks and can add to the info please do.

A WMS to WMS measurement for an AD 1 ton dual wheel truck front axle.

For an AD COE in addition to a WMS to WMS measurement also need an accurate width of the axle beam from center of one kingpin lock bolt hole to the other?

Any other trucks/axles you have that might fit into these plans and we don't already have info on?

Thanks,
Grigg

Grigg, If I get some time this next week I will measure the WMS of my '49 3800 DRW. Loving what I am seeing. Fingers crossed that this would become a workable option.

Of course, by swapping out the spindles and hubs, etc., makes using the P-30 a very simple option. Disc brakes, radial tires, man now all I need is A/C and power steering...

Grigg,
For the record I just wanted to take a second to say thanks to you and the rest of the "grandmasters" for posting this kind of info. I am sure I am only one of a ton of people eagerly awaiting for you and them to solve this puzzle so we can all go forward and benefit from your solution. Thanks!

Jon, if you've had a chance to measure please do let us know what you found, and I'll see if we can answer the question about how well this works for AD dual wheel 1 tons.

Thanks,
Grigg

Hey Guys,

Been a long time since I've posted here. But I am still interested in these big bolts and this is the brake/spindle swap I have been thinking about for the last 6 months. I have a question though, who is the actual front axle manufacturer and what is the model for the 5/10 lug P30 front axle? Spicer? Dana? Eaton? I am trying to source the assemblies from a large truck wrecker and he wants to know the manufacturer and model of the axle, I can't seem to get him to look it up by truck application.

Thanx a bunch,
Jaysin

Rockwell.... but I've never seen it listed or referred to by that, I've only noticed the Rockwell logo on some of the parts.
I suspect it is better known as a GM axle which makes a lot of sense because I've never ever seen one under anything else (from the factory).

If you can't get a wrecking yard to find something by application you need to find a real wrecking yard...

Grigg

Here's more info on the single wheel hub and fitting them on P-30 spindles, the inner bearing is the problem.

Here's what I found about bearings....
Already knew outers are the same NAPA 15103-S so we'll just be talking about the inner wheel bearing, the big one.

The single wheel hub to use is NAPA part number 4885580.
It uses inner bearing "Chicago Rawhide BR35" same as "Timken SET45" same as "Timken numbers LM501349 cone and LM501310 cup"
The ID is 1.625" and OD is 2.891"

The stock P30 hub/spindle takes inner bearing
"Timken numbers 26884 cone and 26823 cup"
ID is 1.688" and OD is 3.000"

Ideally there would be a bearing cup with the small 2.891" OD that fits the single wheel hub and a compatible cone with the large ID of 1.688"

It has been suggested that the following bearing may be a partial solution.
"Chicago Rawhide BR50" same as "Timken SET47" same as "Timken numbers LM102949 cone and LM102910 cup"
Has the correct OD of 2.891" and the ID is a larger than needed at 1.781"


So two or four options,
1: The spindle can be turned 0.063" so the stock single wheel inner bearing SET45 fits. If a large radius is kept in the corner strength shouldn't be an issue after removing only 1/32" per side.
2: The bearing SET47 could be used. It has the same 0.770" assembled width as SET45. To fit on the spindle a thin wall bushing would need to be made with 1.688" ID and 1.781" OD... That's only 0.093" difference so 0.0465" wall thickness. One option if just making the sleeve the right size to start with doesn't work is to shrink it on the spindle and then turn/grind the OD to final dimension.
3: find a suitable conversion bearing with 2.891" OD and 1.688" ID (No luck so far)
4: Have that bearing made; which apparently is possible but at what quantity and price?

More on option #2!
Parker shaft wear sleeve number WS1976 with ID of 1.687", OD of 1.813", and 0.625" wide could be a great starting point, still needs to be ground or turned down about 1/32" after installation. (could not find yet a another different bearing that would work without turning the sleeve)

Grigg

Hey guys, I'm the proud new owner of a '54 3800 and am looking to tackle the disc brake conversion problem as well. I've been looking online and over in the 67-72chevytrucks.com forum and found a guy who converted to disc on his 1951 3800 in basically a bolt on fashion. He descibes his final approach at post #22. I'm trying to figure out his front bracket right now and see if I can get one made as a one piece steel water jetted instead of welding two plates together. Below is the link to the post.

http://67-72chevytrucks.com/vboard/showthread.php?t=440043

And for pictures:
He gave me the link, and just got his permission to share. I'm not sure what bearing he used, but I am assuming that they are ball bearings.

https://picasaweb.google.com/mitchell.lmdangerous.rish/1951DiscBrakePhotos?feat=email#

I'm just getting into this project myself, and am looking for guidance as well. Thanks all!

Just a reminder to please keep this thread about front disc brakes only.
Thanks,
Grigg

Just a thought couldn't maybe a 4X4 front hub assy with disk brakes be grafted onto the Big Bolt front axel.The older ones have sort of link pin type set up so without an axel shaft in the way you could run a the pin all the way through.You would then only have to run a bolt through the center of the hub with a Washer or metal disk and gasket to seal it up. There are some tall and not so wide 16 inch tires. These ars close to looking like a 7.50- 20 tire .So they would not change the apperance to much
Or if you know a good welder you could make a nice tube axel also useing pieces of the 4X4 front axel & hub this would be very east to do. The recivers for the front hubs are pressed into the axel tubes and welded so cut them off chuck them up in a lathe turn off the tube and weld .For a jig you would have already figured how long the tube has to be ,so you would bolt your spring pirches to the springs lay your tube accross center it and only tack the perches on.Then level the truck up side to side .Next you would have to a bar turned so it would fit down through the top and bottom pin holes on the hub reciver with enough extra so you could place that magnetic thing that you can check for angle (sorry forgot the word)next you would need your tires on the rims so you can set the height of the truck .Now you can tap the hub recivers into the tubes ,you would have turned them in the lathe so that they are snugg but if you heat them a little to turn them to set the caster once the caster is set tack them good .Now unbolt it from the truck put on a welders table clamp it down good tack a few baces on so it has no chance to move and weld that sucker up .Now you have disk brakes just an idea