Speedway Tech Talk - Steering Box, U-Joint and Shaft Combinations
Speedway Street Tech Steve brought some steering parts for us to look at. He brought three different steering boxes and then some U-joints and steering shafts that he talks about in the above video.
The first box is our Reversed Corvair box, this is popular on some of the lighter street rods for traditional style steering. Traditional steering is where your drag link runs down the left side of the frame rail, from the pitman arm to your left front wheel. That's primarily used on T-Buckets and some of the lighter cars. Next up is our Vega steering box, which is used with cross steering applications. This application is where the drag link runs from the steering box over to the right front wheel. Cross steering does tend to have the least amount of bump steer, so that's the one that is usually more favorable. The third is a new offering that Speedway Motors has, our Power Vega box, which allows you to have power steering on some of the heavier cars. Think along the lines of doing a gasser recreation, and you want to drive it on the street a little bit more. This makes it a little easier and more enjoyable to drive on the street.
We’ve also got a couple different steering shaft styles here. First is a basic steering shaft, it's a 3/4” solid steel round steering shaft, which is used with a U-Joint like the one shown in the video. It’s 3/4” round on both ends, and the steering shaft slides on and then is welded on, and then you're good to go. Another steering shaft featured is a combination shaft, this has the smoothness of the round shaft, but has the DD milled on each end. This is where you would use a U-joint like the one shown in the video. It will slide on the DD end of the steering shaft, and there's a little set screw that holds it tight.
Speedway Motors offers two versions of completely DD shafts, one DD is a plain steel shaft with the DD milled all the way down the full length of it. This benefits those of us who need an odd length steering shaft, and like the other one it does use that same DD U-joint. This also is available in a polished stainless steel, that way you can have everything all polished up and it looks really nice.
When it comes to U-joints, one of the main things our Techs get questions on is how many splines the steering box has. With the ones we offer, we're already going to know the spline count and the diameter. In case you are unsure of the spline count on your box, put a little chalk mark across the middle of it and start at one side of the mark, and just count around to the other side. Double that and that gives you the total spline count. Another method is to use a paint pen and mark one spline, then count around the shaft.
On some of the factory boxes you may see they have something called a dummy spline, and that was used at the factory. As the cars were coming down the assembly line, it made it easier for the guys to stick the column in, and that way they didn't have to worry about anything being lined up. One thing you'll want to do is always measure the outside of the steering shaft to get the diameter. Then after you count the number of splines, we can generally get you fixed up with the U-Joint you need.
With the U-joints Steve brought, we've looked at the one that is a standard round style, which will get you about 30° of misalignment. He also shows a double U-joint for some of the applications where you have a big engine in a small car, like a Hemi in a Model A, or something like that. You may have to use a double U-joint, this will get you about 70° of misalignment on it.
One featured in the video is from Unisteer, and it has a different type of way to retain it. Where most of them just have a set screw, this one actually has a pinch bolt. Which what you'll need to do when you put the DD Shaft inside there is, as you can see it doesn't fit all the way through there. So what you'll need to do is remove the pinch bolt and seat the shaft, then mark it and remove it. Then you can notch the shaft for the pinch bolt to go through. Then all this will need to be torqued to 45 ft/lbs. to get you a nice, tight fit.
Steve also shows one more thing. It's our support heim. You definitely want to use a support heim when you're using three or more U-Joints, or if you're using double U-joints. The support heim is .007” oversized, so it slides easily over the round or DD steering shafts.
