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

The pins look to be more than .070" difference in diameter, according to your pic, and the other pic showing the big bushing the small bushing, and the sleeve you turned shows that too. I get what you're saying about the axle and why that wouldn't be ideal, but the bushing numbers don't jive. Unless I'm lookin at the wrong pics, seems the p30 bushing is already bigger than the od of the smaller one. Whatever, it looks like a very viable solution.

Oh, and that Napa kingpin number you suggest, is it 8" long like the p30?

Not sure what pictures youre looking at, I have also adapted some big Spicer axles, that might be what you're seeing.


The P30 spindles to 2 ton axle works as I describe, have a set of nested stock P30 and 2 ton bushings here on the bench in P30 spindles.
Kingpin is 6.344" long for both 2 ton and P-30.

Grigg

Just uploaded pictures of the thin bushings and fitting the stock (replacement) 2 ton kingpin bushings in them.

this album
https://picasaweb.google.com/118082002072608219229/2TonDiscBrakeUpgradeForOldGMTrucks

Here are the bushings
https://picasaweb.google.com/118082...pgradeForOldGMTrucks#5830825462749288338
As you can see the bushings that come in the P-30 spindles can be bored/reamed to accept the 2 ton bushings.
More pictures in there of reaming as well.

Grigg

Hi Grigg, I don't want to be a pain in the backside, but I get "page cannot be found" when I take the link to picasaweb. Sorry for the hassle!

best wishes,

Les

Hum, I'll work on it Monday... try the link in my signature and look for the album there.

Grigg

Ok is there a new condensed version of what to do to put disk's on a stock axle? all the originals no longer have any pictures :-(

Sorry the picture links have died, they are all in a new album listed in the very first post of this thread.

No, nothing more condensed than this thread. It works well for the 1.5 and 2 ton trucks with 5/10 lug wheels. Doesn't so easily work for the single wheel trucks, and don't have dimensions on an 8 lug dual wheel truck to know how well that works out.

Grigg:

I have an 8 lug DRW. if you want me to take some dimensions off of it, let me know.

Tj

What is the WMS to WMS measurement, and year truck?
To get an accurate measurement I remove the wheels, set the steering wheel to straight ahead, put a straight edge on both hubs so they're as close to center up and down as you can and level to the ground. Then measure the width between them both forward of and behind the axle, then take the average.

Grigg

I'm on it... its a 54 3800.

front, rear or both?

engine is coming out next wednesday. I"ll prob pull wheels the week after that.

Front please.
Rear if you want to, can't hurt.

Hi Grigg, do you have part numbers for P30 spindles? And 5/10 lug front rotors?

Just a thought ,it wouldn't be that hard to make a pair of hubs and bolt a pair of smaller calipers one top and bottom .The only small problem would be bleeding the bottom one .You would have to take it off to bleed so the bleeer is pointing up with something between the brake pads.This would be a cheaper way to to go if have a lathe and your a good fabricator
Just a thought Paul

I don't have part numbers for the spindles, rotors I've had no trouble looking up at NAPA.

Paul,
I have several lathes and am probably a decent fabricator... I'm absolutely sure the above method of swapping existing P30 parts is by far cheaper, faster, and less trouble than machining brand new hubs from scratch as well as designing and fabricating caliper brackets.

The beauty of the P-30 spindle swap for the 1.5 or 2 ton AD trucks is the only machine work necessary is boring and reaming some bushings.

Grigg

HELP...
I've got a '00 chevy HD3500 solid axle with discs and trying to swap sides to get the center-link behind the axle to go into my '64. It's got 4, 1 1/8 bolts that hold the hub to the king pin but trying to pull the calipers off.
EVERYTHING came to a screeching halt!!

It's NOT like the regular sliding caliper, it's got a tapered hex/allen screw holding what looks like the slider..
The caliper looks like its' cast INTO the hub...????
I've 'googled' and all I see is the 8-lug regular style caliper. not what I'VE got..

What the HECK OVER?

I'll try and post pics of it tomorrow.

Errol

Remove Allen screw, slide shim/keeper out the side, caliper flops out.

Take the bolt out, the use a punch to drive the slider out. It is two pieces that will come out, the top one has a bow in it that keeps things tight.

OOOooops..
If it was a snake..

SO, I'm thinking IN THEORY that It'll work swapping the sides to use the stock steering box, but the 'bus' one is SURE BEEFY! Man that thing is big.
Does anyone know if swapping messes up my angles and any 'ackerman' effect of the geometry??

I may have to make an adapter or look for another power box.

Thanks again. Errol

OK, gone through the whole thread and it's mostly condensed to spindles, king pins, yadda yadda.
Now are all you guys that are doing/done this swap STILL using the Hydro-VAC and different prop valves or something else?

I'm going with a Hydro-BOOST set-up and would love to see some diagrams/exploded views of how to hook the lines up..
Someone forgot to mark them when they took them off for ME...

Off to the 'build' section.
Errol

This thread is for and about swapping the spindles, king pins, rotors and so on.
It does not cover the master cylinder and booster aspects of the swap, did not set out to and don't want to in this thread. That said, hydroboost is what I have used and it works very well.

I am having a super hard time finding a P30 axle for my conversion. The car-parts.com site does not have a listing for P30's so it's really had to locate one. Most of the yards in my area (Tampa FL) have scrapped them. If anyone has a link to some I am getting desperate. I just really need the spindles hubs and steering arm.
Thanks
Dave

Look on craiglsist for an older nearly dead RV. I would expect Florida to have plenty of RV's sitting around. You may find one at a good enough price to pull the axle(s), scrap the rest, and make your money back. Many RV's have low miles also.

Grigg

I am finding RV's but most have A arm front suspension. Looking at a early Kodiak 10 lug axle tomorrow. Since P30's seem to be in scrap heaven.

Most all of the Chevy/GMC RV's I find are A arm style. Still looking but starting to look out of state (desperate).
I found a Kodiak axle and was wondering if I could cut off the end of that axle and weld it on to mine. Can that be done safely?

I know at one point in this conversation you guys were talking about bearings. I found this on another site:

"I finally found some for the 3/4 ton and 1 ton trucks.
On Chevofthe40s.com
Part #909025R(outer)
#909026R(Inner)
I contacted customer service and they assured me that these were taper roller bearing replacements for the 3/4 ton and 1 ton trucks.

Take it for what its worth...Let me know if anyone has tried these bearings.
Nate
__________________

OK, well maybe I should have checked the site before I posted. It's not there any longer but maybe someone could cross reference the part numbers???
Nate

I installed the tapered bearings when I did the disc brake upgrade on my 1 Ton. I can't compare any difference since I never drove my truck prior.

Nate,
Here is the correct link to Chevs of the 40's
https://www.chevsofthe40s.com

I bought mine from them for my 1951 GMC 1 ton and they appear to be good quality bearings, I am probably going to instal them this winter. P/N are 909026R and 909025R.

Dave

Dave,
Thanks for the info. Wow, I did not realize how much those bearings are! Glad to know that they are available because that has been a huge portion of the discussion for switching to disc front brakes.
Nate

You guys are incredible!Ive got an old 65 c60 truck Ive been wanting to do a disc brake swap on and thought I was limited to using parts off of a newer c60-70 truck,This gives me more options.

Grigg, I have a 3500HD complete front axle I was going to narrow and swap into my 50 model 6400. But after reading through this thread Id like to try and swap just the disc brake setup off the HD front axle onto my truck. I know you used the P30 setup, but do you have any info, instructions, or parts list for doing the same with my 3500HD parts??

Mike
FASTRED68@aol.com

You can do the exact same spindle and brake swap with the 3500HD front axle as you could with the P30, those parts are the very same.

The difference is the steering linkage and the arms or bell cranks bolted to the spindles.
The P30 tie rod and drag link are in the same places as they are on your old 2 ton, this makes for very little adapting (can usually use original tie rod, reaming arms to fit if necessary). Also makes steering and drag link simple to adapt to the original box.
The 3500HD has all the steering linkage in front of the axle, a "Y" type it might be called where the drag link is anchored to the tie rod. This setup may or may not easily fit above springs and under oil pan. The major problem is you'd need a different steering box to make it work. I have used this setup on my truck but at the time I had no idea the P30 version even existed, that is what I should have used.


Grigg

<<<The 3500HD has all the steering linkage in front of the axle>>>

What do you think about switching sides so that steering linkage is behind axle? Calipers would be on front side but that wouldn't matter. Im pretty sure the caster is built into the axle so it shouldn't affect alignment??

Mike

It would mess up the steering geometry, the Ackerman angle.
Ideally when looking down on the truck if you draw a line from each kingpin back to the center of the rear axle then also on those lines are the centers of your tierod ends.
If steering arms are forward of the kingpin the tie rod ends ought to be wider than the king pins. If you flip it around they would still be wider but now well outside this line from kingpin to center of rear axle.

Even if it worked out you need a different steering box..

Just use the P30 steering arms and save yourself a lot of trouble.

<<<Just use the P30 steering arms and save yourself a lot of trouble.>>>

Will they bolt to my spindles?

Mike

And is there any other source for them other than a salvage yard?

Mike

<<<Just use the P30 steering arms and save yourself a lot of trouble.>>>

Grigg I've had no luck finding these arms. Do you have a source?

Thanks, Mike

They come on a complete P-30 I-beam front axle. Even if you found the part numbers and tried to order them from GM I suspect it'll be easier and cheaper to get a whole used axle.

ok new to the big bolt world here and I'm wanting to do the conversion for my 49 chevy 4400 1.5 ton. disk brakes are going to be a must for me as i am going to use it as a tow rig and want to be able to stop my load.
i have been over this entire board and many others and no one answers the questions below clearly. i see that it is possible to do a disc conversion but i can't find info as to how to really start the process.

any and all info will be greatly appreciated my number is 2517098264 if you would rather call and walk me through something other than typing it. or if you are close to mobile alabama id love to see what you have done.

Q1. is their a bolt on kit?
Q2. is a axle swap for possible 4x4 an option that may be easier?
Q3. Where can i purchase the kit if it is available or are their part numbers that will make it easy to pice together a kit?
Q4. would the current drums on the truck be sufficient with just a hydro boost system replacing the stock master cylinder.