Business in the Backpart

I haven’t had the opportunity to do rear disc brakes on anything being that I mostly deal with old hot rods that don’t make a ton of power. I don’t even like disc brakes on the front of my old hot rods. I think they look silly compared to big ole awesome drum brakes on I beam axles.

I do however think disc brakes have their place in the Hot Rod world for sure, especially with all the big motor swaps that go into some of them. Disc brakes offer several advantages to drums and for some builds they fit the bill!

What’s awesome about this project is that it gave me a little trouble like almost every single project I tackle. Believe it or not I embrace projects that fight back. We pretty much already know that failure can be one of the greatest teachers. I barely remember projects or portions of projects that go together smoothly. When I fail I ALWAYS, I mean SOMETIMES, remember what happened and learn from it. Other times I have to screw it up 2-4 times before it's beat into me. I try to not let that happen!

When we originally started talking about running four wheel disc brakes on my buddy Joe’s Model A, I started thinking to myself…"Man I have installed a lot of different hot rod parts and built several different things. How could this rear disc brake kit go wrong?". I checked out the instructions on the Speedway Motors website and the job seemed simple so I ordered it up to try it out.

From the beginning this whole project kicked back a little bit. We were told this was a 9” Ford rear end when we purchased it second hand. I honestly had no idea there were so many different 8” and 9” rear diffs out there. I ordered up Speedway's Ford 9" Rearend Bolt-On Rear Disc Brake Kit and started putting it together. Nothing was lining up or fitting right.

At first we thought if we grind it or take a little meat off, it would work. We didn’t feel good about doing this and started looking at things a little closer. Turns out this kit had the car bolt patterns in it! We wanted the 5 on 5.5 bolt pattern as we already had wheels and we did not feel this kit was the one for us. A simple measurement of axle flanges and offsets could have told us what we had, but we thought we knew what we had. Measure 2 times order parts 1 time!

A little bit of investigation turned up the fact that we had a TRUCK rear housing! Aha! Well, that makes a little more sense it wasn’t fitting and had the wrong bolt pattern. We boxed it back up nicely and I returned it. Speedway Motors return policy is really good. If it’s been less than 60 days, the product is in new resalable condition and has been placed in the factory packaging you are usually good to go. We found the Speedway 9” Ford Truck Rear End Disc Brake Kit. Awesome! Nope. Not awesome. At that time the kit was back ordered for two months! Just another kick to the you know what…and heck yeah the whole rear end was out of the car, old drums and axle removed so what better way to sit for 2 months!

We cut the tape and unboxed the kit like it was Christmas!! This kit was very nicely packaged and I was impressed at the quality of the pieces included in this kit. I read the instructions for about the 20th time. I read them out loud so Joe and I were on the same page! The instructions were pretty straight forward but I would say some of the information you need to complete this kit was missing.

The missing information was not anything more than what it takes to complete about any kit. What I mean by that , is the instructions to most of our kits are going to explain how to install something on a particular part of your car and it is only known to work with whatever portion of the car it says it will work with. It does not take into consideration that parts can change over the years or the fact that we sometimes get misinformation when we buy parts second hand and that in the 50-60 years of somethings existence it could have been messed with in a way that may not be noticeable by the untrained eye.

After the drum brake setup and axles are removed from the housing. You will select a spacer and primary bracket that fits your application. This kit covers a few different rear ends with multiple back spacing. We found that there was only 1 set that worked with our rear end. The other brackets were kind of close, but not close enough to second guess which ones we needed.

We selected the spacer and brackets that fit our application. We started to fit these brackets onto the axle housing. At first they appeared to orient the opposite of the directions. We weren’t trying hard enough. We were under the impression that this kit would not require any modification to fit, but found out that there were a few minor things to do to get this installed correctly and orientated properly.

(we messed around with installing the brackets a few different ways)

The pictures to the right show what we ended up with the first night. We had found that the orientation of the bracket was backwards from the directions and did not quite look right. The instructions show that you need to put the rectangular brackets in between the primary and secondary brackets to get the proper backspacing.

We could only get the round tube spacers to fit on the primary bracket and used the rectangular spacers to take up the end of the bolts. This didn’t feel right and we wanted it to fit like the instructions state it should.

The other mild modification needed was to slightly grind the rectangular brackets to fit around the brake flange. When we originally mocked this up this seemed like it was going to need to have the brake flange ground and the rectangular spacers that was not the case when we had everything mounted correctly and tight.