Hey guys, I'm building a 40 Merc and would like to ad disk brakes to the front of the car. I have a stock suspension set up except for a dropped axle. I'd like to use the stock 16" steel wheels but somehow some of these "kits" don't want you to use stock wheels. Speedway has a disk brake kit but they say stock wheels won't fit. Do they really not fit or is this just a liability issue for them? Is a 11.75" rotor too big? Can I modify/grind the calipers? Can anything be done to make them work? I'm tempted to buy the El cheapo, Speedway set up, for $320 but I have yet to hear a definitive reason why this kit does not work with stock wheels. Thanks, Chris
The only way to know for sure is to find someone who has that disk brake kit installed on their car and see if the wheel fits, if not, an option is to replace the hoops on the wheels.
You may get by using wheel spacers, but you would need to verify. The other issue is, alot of the disc brake kits move the wheel out which will compound the issue.
True there, it could be nothing more than running a thin "disk brake" spacer like we did back in the 70's with pre disk wheels on disk brakes. I even had to use a set with the old set of 14 inch Crager Mach 8 wheels I ran on the 48 with 54 drums for a number of years. Most of it is how much room do you need to clear the caliper.
yep....what was said - we all need to remember the stock early Ford wheels were not made to capable with disk brakes....especially a 11" set up....find someone that's made the modification....
Somewhere in the questions & answers on Speedway's web sight they give some measurements, we used them to measure some 15" wheels to make sure they fit before ordering the kit. On another install we had to grind the caliper a little here and there to get a different set of 15's to fit. Could always pick up a rotor & caliper at O'Reillys to get a closer idea on fit and return them when done. That kit does not add any extra to the tread width; in fact the WMS to WMS is slightly less than stock. If your axle was narrowed a little when dropped, it may give you room for a small spacer.
Chris, I took this answer from the Q&A section on that kit. "You can vary the backspace any dimension wanted as long as the inside of the wheel in the area of the caliper is over 14.50". The caliper sits withing 3/4" of the mount surface for the wheel so you can lay a ruler or stick the 14.5" long on the back side of the wheel across the center and measure down to the mount surface where it will bolt to the hub. Anything more than 3/4" will require that much spacer to clear the caliper. These are 11 3/4" diameter rotors." So, maybe that info can help you measure your wheel to see if there is enough room, or if grinding on the caliper is a viable solution.
I used the Speedway disc kit with 5 1/2" bolt circle on my '40 with a dropped axle & using early F- 100 15" wheels. The 15" wheels cleared the caliper by using a 1/4" spacer between the hub & wheel. Spacer was sourced from Advance auto parts. I would think a stock 16" wheel would have no issues. Any wheel offset was a non issue.
One thing not mentioned is the wheel center hole. A lot of disc hubs have a larger center hole the older wheels won't fit over. I've run into that with older steel wheels from drum brakes trying to use them on disc brake cars, aftermarket wheels usually have a larger hole so it doesn't affect them as much.
Probably not real useful pictures; but shows the caliper clearance around a 15" wheel with that kit. Should have asked my kid last night if he had a Merc' wheel I could have grabbed; but I didn't plan on going up to the other shop today.
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