Posted by Paul (in NY [108.162.241.29] on Wednesday, July 17, 2019 at 09:44:26 :
In Reply to: W300 disc brake conversion info needed posted by Scott @SKL Mechanics [162.158.126.13] on Tuesday, July 16, 2019 at 12:38:49 :
Ok, I will try to help Ned and give you some things to look at and ponder. But first a disclaimer !
I built my W300 10 or more years ago. When I build a truck or other vehicle, I make a bound note book with all part numbers used as well as any special work. My W300 got disks on all 4 and many notes and drawings were included in the bound book. When I sold the truck, the new owner got the book. I am giving you this info all from memory. After building the W300, I built a diesel CJ7, and 4 corvettes. I will admit my memory is hazy on the exact build of disk brakes.
So here we go. The rear disks were fab’ed using Chevy Calipers and Rotors, using the stock
single wheel rear hubs. Everything, and I mean everything was a custom build so the rotor sat at the correct position in regards to the calipers. I cut, turned and welded my own made rotor plates which were exactly measured and placed before welding on the hubs. Then finally, the entire assembly had to be turned and trued in a lathe. The caliper mounting plates, I cut and fab’ed to accept the Chevy
Calipers and also they had to be clocked in mounting to miss the springs and something ?? else that was in the way. The rears turned out perfect.
While the M715 did use Dana 70 axles, the M715 hubs will NOT work on a W300 with Dana 70 Axles.
The problem from memory was one of 2 things. Wither the M715 hubs on a W300 pushed the wheels/tires out to far so they mounted past the fenders or the M715 hubs themselves were to long and the hub stuck out past the fender making them a easy target to remove or adjust if you hit something. So realizing there M715 hubs would not work as I required, as with the rear, I built my own design front disks. I used Ford calipers and ford caliper mounting plate as well as Ford rotors.
Once again, I cut my own rotor plates from stock turned and trued them. With exacting mock up
actually clamping the various parts on the front knuckle/hub I tacked them in place. Believe me this is a exact fab. If everything is not perfect it is not going to work and the rotor among other issues will rub on the caliper.
Once everything was to my requirements, I quit for the day. The next morning I rechecked the entire design for clearance and operation. When I was happy, I removed the tacked assembly from the truck and took it to the bench. Using a piece of .750” stock as a build/weld platform, I made sure everything was square and proper. Everything was indicated as close as I could get it. The entire assemble was then final welded. Then the hub with rotor plate had to be turned in a lathe so it ran absolutely true. I put it on the W300 and it worked perfect the first time. I smiled, it was beautiful.
The bottom line is there was nothing off shelf that would or could be a direct Plug N Play bolt on. Is all custom design and fab. If you do not have the ability to custom fab or weld properly……don’t start this job !!!
The rear rotors were used on a Chevy 1978 to 1987 3/4T 4x4
The rear calipers were used on a Chevy 1971-1978 3/4T 4x4
I am confident on the above and I used the on all my builds.
The front rotors/calipers and caliper mountain plates were Ford from the the Mid 80’s if I remember correct.
Click on the link at the bottom of my post. Its titled Pictorial Repair Albums YOU CAN DO. Then go down to Album # 11 Power Giant W300 and click. Double click on the first thumbnail picture to go to full screen. You can then use the arrows to step through full screen pictures, You will have to go thru the pictures till you get the the disk brake build. There are quite a few pictures on the above mentioned build. The pictures were never designed as a build cookbook. What you see is all the pictures of the disk build I have…..there are no more.
Its my policy not to get involved with commercial for profit businesses. I have been burned to many times. But to help NED, I will help as much as I can. Hope the above ramblings in some way help you sort out the needed fab/build work on Ned’s truck
Paul
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