The Stovebolt Site Forums The Shop Area Engine Shop Disc brakes for a 3600, Part II

I was reading over the "Dodge 2500 rotor for a 3600" thread and realized that we are all over the place with this. P30 axles, hats for hubs, full rotors for spindles, etc. We're bouncing all over the place. I have a simple solution in my head but it is difficult for me to do anything with out the actual parts in my hand. The path I want to start with is a full 3/4 ton or 1 ton ( single rear wheel ) 8 lug rotor. On late model GM trucks, they are usually the same part. I want to design a collar ( NOT A SLEEVE ) that a grease seal will seal around and a tapered bearing will butt up against. It will basically take the space of the flange on the inner bearing of the original ball set up. And it will have to be an interferance fit. We don't want it spinning while you are rolling down the road! If this won't work ( and it might not, I will keep in mind a sleeve for a larger diameter tapered bearing ) then I'd like to look into fitting a "hat" onto the original hub. If that won't work, then MAYBE a later model spindle. But I'd like to do it in that order! I won't even worry about doing a caliper bracket until the rotor is figured out.

SO, what I have are spec books for bearings and seals. Old catalogs. New catalogs. I have a general selection of actual bearings and seals. I have access to different types of 3/4 and 1 ton rotors. I can cross applications all day long. What I don't have is an old spindle or spindle with hub. I have nothing I can physically fit together. It's like bumping around in a dark room.

So, you know what's coming! Does anybody have an assembly they can toss my way. I'd like to solve this problem, give the Stovebolt kingdom the part numbers and specs for the special stuff and leave it up to whoever wants to produce / manufacture the hard parts! Or at least, give it all to Rick in VA so his truck can be the test bed!

If not, I can always go back to measuring for a driveshaft on my 'Burb. Or roll it down to the muffler shop for an exhaust system. Or start grinding all of that rust out of the roof!

I have a 3800 I can take apart in the spring... Until then I need to keep an axle under it so I can move it around.

I can wait.

I have duallys on my '57, 3600. If you wanted to go that route, I can take apart my front end after the car show in Oct. I am local to you...the posts on the subject do get dizzying. Hope this doesn't add to the cofusion.

Are they the same spindle as the single rear wheel? Also, are they the same as 3800?? It would be nice to knock out all these heavys in one shot!!

I'm not trying to complicate things here, but- A few years ago I came across a gentleman's site where he had converted his 3600 to front disc brakes. He had detailed it quite well. I had boodmarked his site (but I now have a new 'puter and can't access the bookmarks on that hard drive) because I had figured I might do that for my wife's 1955 1st 3600. I have tried,in vain, to locate his site again.

As I seem to recall he had used parts from a 1987 3/4 ton chevy. He had to make or alter the plate, but it seemed pretty easy to do (or I wouldn't have thought I could do it-LOL). My reasons for liking his approach was it was (or looked) easy, parts were easy to get, it kept the orignal stance of the truck and you couldn't even tell (without removing the tire) that you had disc brakes.

Someone with some books and knowledge may know more about this then I surely do.

Who knows where a spindle can be purchased? I wouldn't mind sending NMSmith thirty or forty bucks to buy one to check out. If three or four of us do this we should be able to buy a spindle somewhere that he can work on.
What do you think?
Rick

Who knows where a spindle can be purchased? I wouldn't mind sending NMSmith thirty or forty bucks to buy one to check out. If three or four of us do this we should be able to buy a spindle somewhere that he can work on.
What do you think?
Rick

Here's an email that came to me from "oletrucks":

From R.D. Hulst: [email protected]... for my '51 3/4 ton...used a disc brake setup from a 1984 F250 Rear Wheel Drive:
Inner Bearings
Timken Cone L689149
Timken Cup L68110
This gives a bearing ID of 1.3775", meaning you have to have the inner end of the spindles machined down to this diameter and OD of 2.3280 and a bearing width of 0.625". You'll need to make a spacer with width of 0.6250", OD no larger than 2.3280" and an ID of 1.3775 to keep the rotor from grinding against the spindle mount points.
Outer bearings:
Timken Cone: LM12748
Timken Cup: LM12710
This gives the following bearing dimensions: ID 0.8437" OD 1.7810" W 0.6100
I had to make an outer spacer to ensure the nut didn't run out of threads.
Seal: NAPA NOS19743
Rotor left: NAPA UBP 85682
Rotor right: NAPA UBP 85682
Caliper Left: NAPA RBP 4424032MS (single piston)
Caliper Right: NAPA RBP 4424033ms (single piston)

I had to make caliper brakets that look alot like the ones you see with the 1/2 ton conversion kits. This was trial and error. Replaced the original wheels with a set from an '84 F250.

MNSmith,
Sorry to digress as I know you wanted to stay on track with your plan. In answer to your question as to whether my '57, 3600 hub is same as single wheel, the truth is, I don't know. From what I gather in these postings it is not. As to whether it is same as one ton, don't know that either. Perhaps someone reading this knows for sure if it is. I can take photos and post or email them if needed.

Good job, orchidskip! Looks like problem solved for the 3600 single rear wheel! If I remember correctly, F**d and GM 8 lug patterns were the same in the mid to late eighties. The F250 should be 8 lug.

Time to compare these numbers to a 3800 spindle, for those wanting disc brakes for their 3800. Also, thanks to Rick in VA's picture (http://i39.photobucket.com/albums/e187/Sawmill/107-0778_IMG-1.jpg) we can compare spindle lengths with the 3600.

BTW, if the spindle is the same between the 3600 single rear wheel and the dually, you should be able to use the dually rotor with the same seal and inner bearings, once you have your spindle machined. Late model 3/4 tons and 1 tons usually follow this design. They just used different rotors. ( and drums.) Go back to the other thread and you'll see in the rotor pictures posted that the bearing areas are the same. Just that one is designed for a dually wheel and the other a single wheel. Same spindle.

Just for my own curiosity, someone mic the inner bearing diameter on their spindle. Sounds like R.D.Hulst already looked but I want to verify that there isn't a tapered replacement that will slide right on.

I think I would still like to get a spindle to make the caliper plates then make a drawing for a tech tip here at the Stovebolt. That way the inforamtion would be available to all. Just print it up and take it to your local machinist (or make it yourself!)

I miked the bearing, 1.406" The dial calipers I used are not the greatest but it should be accurate within a thou or two.
Rick

Some good news. A co-worker has a 1955.2 3/4 ton that he just clipped. He said he'll save me the old axle. Now I just need to find time to go pick it up.

Thanks for measuring the bearing, Rick. I'll start hitting the books!

Well, good news and bad news. Good news is I found a bearing with a 1.406 bore. Bad news is that it is an inch thick. Almost twice the size that a F250 or 2500 Gm would take. Back the the books!!