Choosing a Custom Length Driveshaft - 1967 Chevelle
When you do a radical drive-train swap in a vehicle you’re more than likely to need to do something with your driveshaft. If you’re lucky, that will require shortening it from the stock length. If you’re like me, you need a driveshaft stretcher.
In the past I used a local truck center (Inland Truck Parts) to shorten, balance or fabricate driveshafts. Most of the time, this is the final piece to your puzzle and waiting a week or better for the shop to finish up with your parts is agonizing. That’s after the agony of making sure you’ve conveyed the measurements correctly and the driveshaft you pick up, is going to fit.
Then, in walks Speedway Motors.
I didn’t believe it could be that easy. Now, that’s saying something considering I was sitting on the other side of the cube wall from where this product came to life. Our Merchandising Manager, along with the support of our Purchasing and Customer Service Managers dreamt this program up and made it reality.
They created a single part number for the Universal Steel Custom Length Driveshaft Kit that allows you to select not only your specific length, slip yoke, and u-joints. It’s elegant and foolproof. Trust me I tried.
This brings me to the length measurement. You simply need to know the distance from the face of the seal on your transmission tail shaft to the center of the u-joint cap on the differential yoke. This measure should be taken with the vehicle as close to ride height as possible. I simply put the rear tires on-ramps with the front on jack stands. If your car sits higher than mine or you’re skinnier than I am, you may be able to lay on the floor and shimmy under. I’m not getting stuck again, thank you very much.
Usually, the flat face of the differential yoke is on the center-line of the joint cap. This flat is the other end of your measurement. Driveshafts are customizable down to the half-inch. So, even if you don’t give your kid the dummy end of the tape measure, like I did, you’re probably still gonna be okay. Even if Jonny doesn’t know 3/16” from 13/16”. The slip joint allows some latitude. A hair short is better than too long. You don’t want the driveshaft yoke banging into the tail shaft bushing in the transmission.
Seriously though. It’s really that easy. From that measurement and the components, you choose, all other factors are accounted for in the manufacturing process.
A quick note on u-joints. My particular application uses 1310 u-joints. If you’re not sure which u-joints your differential yoke requires, it’s a good idea to measure and research before starting the order process. Most likely, it’ll be a 1310 joint as well. These shafts are offered with your choice of 1310, 1330, or ultra-beefy 1350 u-joint. (If it’s not already, this would be an excellent tech article. Dibs.)
My driveshaft took three days from placing the order to having in on my doorstep. It took me longer to find time to install it than it took to have it made. Custom. I could get used to that.
