The Stovebolt Site Forums The Shop Area The HiPo Shop ???front disc brakes for a 3600

I've noodled around the internet (and this site) and there doesn't seem to be a front disc brake kit anywhere for a '57, 3600, 3/4 ton, 8 lug hub. Plenty of stuff for 1/2 ton trucks and passenger cars. Even cars like Pakards and Funnybakers but no big trucks. It appears most guys graft a whole independent front suspension onto their frame to replace the straight axle. Please tell me I don't have to do that....

Great post, I also desire to upgrade front brakes on my 3600 while maintaing 8 lug hubs. The only people I have seen do this so far have been complete custom jobs. Is there not any 8 lug disc conversion kits available for origianal axle.

You don't have to graft an IFS to your frame to get disk brakes.

However, there does not appear to be a kit to install disks on straight axle trucks bigger than a half ton. This question comes up often, and no one has yet offered an easy answer.

It can be done, but you'll need to create your own conversion.

According to one guy who has done it, Dodge disks fit the existing hubs better than GM or Ford disks. If you get that far, the next challenge is making a caliper bracket.

Why not swap the 3/4 straight axel for a half ton?
Maybe someone can correct me but I think they mount the same. That way you can keep the straight axel and purchase a kit to fit.

Hi 3600 owners! I have a 1951, 3600 and want to go for disk brakes in the front. I want to keep the axle and 8 lug for the load they can carry. The truck has to work and a Pinto front end is out of the question, and for the same reason I do not want a 5 or 6 lug front end. I can turn the spindles or make sleeves for them as need be. Within the next 6 months I can cut out the brackets with a cnc plasma machine. How about some of us working together. I see the task as having several steps. The first is to determine which, rotor, or hub and rotor is best suited for the upgrade. OldSub suggests Dodge parts. Which Dodge parts would need to be determined, which has the most suitable charactersitis, ie., diameter, depth, thickness, and mounting. Once this is determined, calipers would need to be selected and a drawing make of the bracket. I could make the brackets and do what ever machining of spindles and hubs that may be required. I wouldn't mind doing this for anyone who gets involved and contributes. What do you think?
Rick In VA

I would start with a 12 inch rotor. Any bigger and you will have to grind the caliper down because it will rub in a 16 or 16.5 rim. Try the calipers they used on a 3/4 ton gm truck from the 70s. Those calipers are wider than the camaro type as the disc will be at least 1.125, and probably 1.250 inches thick. If the bleeders or hose connections don't line up or interfere with something, try the commercial chassis calipers... the ones they put on limosenes.

You should be able to use the original hub, and add a slip on rotor. The holes in the rotor are going to be much bigger than the studs on your hubs, so you will have to devise a bushing so you don't bugger up those threads. You can cut some old steel shaft lug nuts, the kind they use for mounting aluminum rims, in about 1/4 inch sections with a band saw. Thread those on to your studs, and it should hold that rotor tight enough. You might also drill and counter sink the flange of the rotor to line up with the existing holes on the hub used for locking that drum down.

Thats all I can add for now.

Adding bushings to the lug holes in the rotor should not be an issue, modern GMs are made with larger holes in the rotor, they do not have any stud damage problems. The real trick is to get the rotor centered to the hub center, hub piloted is a better term. Once the nuts are tight, the rotor will not slip. Some thing that you guys might look into is the late model (2000-2006) Silverado 2500/3500 HD. They have 4-wheel disks that clear 16s. The caliper is mounted to a separate bracket and is dual piston on the front. I think that the braket may be able to be modified to work with the staight axle, the rotor would be an easy slide on to the hub as well. I'm kind of leary of the Dodge rotor, as well as the earlier Chevy rotor, as they are designed to go on the backside of the hub and held on with the stud knurl. They also have a large square hole in the center, to allow it to fit over the hub mounting, that prevents proper centering. A trip to the salvege yard may be in order to get some more ideas on this.
By the by, I have considered this idea for my 1/2 ton, only using 1500 Silverado parts.
I'd also like to note that the rotors for the late Silverado are 1.650" on the front.

One correction, 2000 on up Dodge 8 lug rotors are slip on. The 1998-99 are the "square hole" rotors.

Question. Are the original hubs ball bearing or roller??

BTW, if you don't center the rotor on the hub and you use the studs to center the rotor, I would suggest drilling the hub and installing bigger studs, instead of using bushings.

I think the proper game plane would be to get to roller bearings so you don't have the play of ball bearings, if that's what the 3/4 tons have. Then, find a way to modify the permanent parts and use off-the-shelf stuff that wears. Rotors, pads, etc. In other words, you don't want to have to machine the rotors everytime you need to replace them after a usefull life. Make the hub fit the rotor. Late model Dodge makes a slip off as does Ford. I haven't come across too many GM's to know what they have. I have brake catalogs so I can get the dimensions of the early stuff, one piece rotors but not the later stuff. Bearings for one piece rotors are a little easier as you get the rotor diameter and your new inner diameter then look through a Federal Mogul / National BCA spec book.

I know that GM has slip on after 2000, wasn't sure on Dodge. You're right on the mark on waering items, off the shelf is best for ease of replacement if necessary.

Currently, I don't think I have any Dodge front rotors in stock. Or extra hubs. So I can't measure that stuff. I do have some Ford F450 / 550 front slip on rotors in stock. But those things sit behind some 19.5 rims. In fact, I have F450 / 550 rotors, calipers and caliper cages in stock. Not sure I have anything in salvage right now that I can measure. I wonder if a call to Bendix, the folks that have been designing brake systems for years, would help us out any??

How interesting would it be, to take the 3/4 ton spindle, machine a flat area and bolt the 1998-99 Dodge assembly to it?? That is the way the Dodge set up is! Four bolts hold the "square" rotor / hub assembly to the "spindle / knuckle", (I guess you would call it.) After that, you would have to have an area to bolt the caliper cage to. ( Or do they not have a cage? I forget.)

BTW, my office:

http://www.bunchobikes.com/braketruck1.jpg
http://www.bunchobikes.com/braketruck2.jpg
http://www.bunchobikes.com/braketruck3.jpg
http://www.bunchobikes.com/braketruck4.jpg

Although, I'm doing less of that work these days and more of an all around trouble maker. Like tearing manlifts apart and repairing them:

http://www.bunchobikes.com/pomona1.jpg

Or swapping service bodies on 5 ton trucks. But enough about me. Let's get to the root of this brake problem.

Wow, you guys are great. I run 17.5 inch wheels on this thing so clearance may not be a problem. These big hubs run ball bearings and I'm aware that rollers are a pretty important upgrade as well. Some of what y'all decribed makes sense to me and some of it would require a visual to completely get my mind wrapped around...

MNSmith, do you have a salvage yard???? I like your idea alot...

Nope, no salvage yard. I work on a fleet. When the company has decided that a vehicle is at the end of its usefull life, it sends it to my yard. We evaluate it for redeployment or designate it for auction / sale.

Hi All,
I went to the Advanced Auto web site and looked up the rotor and caliper for a 1998-2000 Dodge and then the 2000-2006 Silerado. Guess what?! The Raybestos part numbers are the same! I guess Raybestos made the replacement parts to fit both. NMSmith, or Longbox55, do you know the diameter of these rotors? Are they 12 or 12.5? The Advanced Auto site did not give sizes.
Rick In VA

12 1/2 for 94-99 dodge, 12 55/64 for 2000-2002 in the old book I have

Typically, a manufacturer will go to a brake company to have a system designed. The 97-99 Dodge 1 ton caliper is the same that GM had been using since the eighties. Aftermarket might renumber them sometimes, though.

MNSmith, Sorry. I hadn't looked at your photos. Now I see that you have a huge facility and what appears to be a mobile brake service truck. So, you are the brake man right????

I asked Grigg about this. If you haven't seen his photo gallery check it out. Here's his reply. He wanted me to point out that this was only his limited view and that he doesn't know everything. Of course, McGiver didn't know everything either...

I don't have a final answer because I am not doing this conversion
myself. However, I have read the post and can comment.

If I were starting this swap I would take a spindle and hub with me to
the parts store and start looking at rotors with the right 8 lug
pattern. Then I would find a nice caliper that is easy to mount and make the
bracket. If none of that worked I would go shopping at the junk yard
to see what I could find.

Some other ideas

look for something with 8 lugs, disk brakes, and an I-beam axle. You
may be able to swap everything from the king pins out. Or perhaps a
complete swap like I did with my narrowed big axle.

As a second choice I would start looking at hubs from a suitable donor
that have a similar bearing placement and may even slide right on and
work with out modification. Bushings could be made to adjust the
location and bore size inside from a 4x4 hub to match that of the stock hub
and use the original bearings. Then the caliper bracket can be made to
fit or a new one made to work.

Perhaps the easiest way is to find a rotor that fits the old hub and
make a caliper bracket.

Another way would be to use the unit bearing hub from a newer truck. I
don't care for them because they can't be serviced and are expensive,
but you may be able to cut the old spindle off and make an adapter to
bolt the unit bearing hub and a caliper bracket to what is left. I would
do lots of thinking of the strength of the setup before committing to
this way.

Hope this helps,
Grigg

Amongst other things!

As an owner of a 59 3/4 ton I've been watching this post with interest. A disc upgrade would be a welcome improvement. If nothing else, if enough people are digging for info, maybe we can come up with a suitable taper wheel bearing upgrade.

John

When I start digging into it, I'll post any findings. I'm hoping others will do same. Thanks all who have contributed to this discussion. Keep checking this topic for updated info.

A gentleman named R.D.Hulst has actually done this using parts from an '84 Ford F250.He kindly provided machinging specs, and part numbers. Let me know if anyone is interested.

Sure! I would love to hear all about it!
Rick

Mr. Hulst used the disc brake set up from an "1984 F250 Rear wheel drive truck. Inner bearings: Timkin Cone L689149,Timkin Cup L68110-This gives a bearing ID of 1.3775",(meaning you 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 0.625", 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:Timkin Cone LM12748,Timkin Cup LM12710- this gives the following bearing dimensions:ID=0.8437" OD=1.7810" W=0.6100". I think I had to make a spacer to ensure the nut didn't run out of threads.
Seal:NAPA NOS19743, Rotor Left:NAPA UBP 85682, Rotor Right :Napa UBP 8562,Caliper Left:NAPA RBP 4424032MSMS(single piston),Caliper Right:NAPA RBP 4424033MS(sinle piston).I had to make up caliper mounting brackets that look a lot like the ones you see with the 1/2/ton conversion kits-trial and error.Original wheels replaced with '84 F250." If you should cross paths with Mr. Hulst buy him a tall beer!

Hi Ironhead,
Great info, one more question. Does this conversion use the Ford hub, or retain the original chevy hub? I'm assuming the original chevy because no mention was made of the Ford.

Thanks, John

No hub. It uses the 1984 Ford rotor.

I am assuming you use the ford hub. Why else would you be turning the existing spindle?

I've seen pictures where a guy used Dodge rotors on the stock hubs and ball bearings. Still had to make a caliper bracket.

The Ford rotor is an integrated hub type. No hub, like the Chevy, is involved. The spindle is machined so common bearings can be used. Think like mid 70's Chevy front disc set up. No hub involved. It's a whole different assembly. Drums go on hubs. Rotors don't, except for a lot of 1999 brakes and later.

The first GM 4x4s with disk brakes used a rotor attached to the hub. This was done on the 1/2 and 3/4 ton trucks. The conversion for 3/4 ton trucks would be the same as that used by the aftermarket vendors for their 6-lug disk conversions.

That is if someone wanted to use their stock hub and bearings. The only thing wrong with the stock ball bearings is the cost compared to timken type bearings.

I thought that drums went on axles, when they are on the rear wheels, on the right side, with left handed threads, held in place by collars, not sleeves, when rotors are keep in place without hubs, that hold the bearings:)
Rick

Haven't seen this post in awhile and haven't had the time to work on my truck lately. By the way, I was the one who passed on the info from the guy who used the Ford brake setup. It came from 'oletrucks' a yahoo group that anyone can sign up for. What I learned from this and another discussion like it is that dually rears means you have a different hub on the front as well so I don't think I can use the old boy's Ford setup. I'm sure learning alot from this discussion though. Seems alot of guys want to do this conversion. Thanks everyone.

If it's an F250, then it is not a dually.

Actually it's my beast that's a dually. I think what the others here have been trying to set up is a single wheel and it seems the problem has been solved for that application. Nice bikes Mr. Smith!!!

Then look at the parts for a 1984 F350. If the inside bearing is similar to the F250 set up, you might be in business!

Yeah, bikes are cool. Especially old Schwinns!!

Orchidskip & all, I have been asking the shops (see CD, Brothers etc.) for a few years now on a stock disc / 8 lug conversion for our 3/4's & CPP...
told me this summer that they might start working on one "IF"
there is enough interest in one....so I say, lets start bugging them...go to www.classicperform.com...you never know, maybe
together we as a group can get something done !
Great discussion by the way !

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Stopping on a dime is not worth as much as it used to be !

Just hung up with CPP, Chuck said that it was a spindle- bearing spacer/ adapter that would have to be turned to adapt a unit & that Ford F2's & F3's are the same as the 1/2 ton Fords...
(lucky Ford 3/4 ers')!
What I gathered from the conversation is, it would not be that difficult....go figure. I think this needs to be studied further !
Does anyone have access to a machine shop that might be able to work this out !!! Just a thought !

Stopping on a dime cost more than it ever did!

I have a good friend in Colorado with a backyard machine shop and a brother in Oregon with a small machine shop in his basement.

I also know someone here in Washington who has begun working on a caliper bracket for this application.

The potential liability exposure of selling a brake conversion is going to slow down anyone thinking of creating one. I wonder how many you would have to sell before you could make money doing it.

Hey Rick in VA, have the '84 Ford rotors worked out on the turned spindles?How about the C20 calipers? Does it look like you can make a bracket to adapt them easily?

Hi ironhead68. I have turned the spindles and the 84 rotor mounts on, but requires different bearings. The set up does work. I have hung the caliper on the rotor and it turns out you have to make a spacer to move the rotor out on the spindle and turn the spacer so it will work with the grease seal. I have done that as well. I am not working on the bracket that will bolt on the spindle and hold the caliper. Mr. Hulst plan has major problems but parts of it work out well. The rotor and bearings and grease seals he suggests work fine. His suggestion for calipers is wrong. I went with 1984 Chevy C20 Calipers. The are a good width and will work with the diameter of the ford rotor. The advantage is they can be mounted with the traditional plate that looks like the plate you see in the 1/2 ton conversions. The caliper he suggests require a "Key" that makes mounting the calipers out of the question. As I said, I am in the process of working out the mounting plate. I will take a picture of the progress in the next couple of days and post it.

Hi ironhead68. I have turned the spindles and the 84 rotor mounts on, but requires different bearings. The set up does work. I have hung the caliper on the rotor and it turns out you have to make a spacer to move the rotor out on the spindle and turn the spacer so it will work with the grease seal. I have done that as well. I am not working on the bracket that will bolt on the spindle and hold the caliper. Mr. Hulst plan has major problems but parts of it work out well. The rotor and bearings and grease seals he suggests work fine. His suggestion for calipers is wrong. I went with 1984 Chevy C20 Calipers. The are a good width and will work with the diameter of the ford rotor. The advantage is they can be mounted with the traditional plate that looks like the plate you see in the 1/2 ton conversions. The caliper he suggests require a "Key" that makes mounting the calipers out of the question. As I said, I am in the process of working out the mounting plate. I will take a picture of the progress in the next couple of days and post it. Rick

Wow I double posted, I am sorry. Any way it should read. "I am now working on the bracket" rather than I am not working.
Rick