If you've been following STREET RODDER for the past year, you've undoubtedly taken notice of some of the work coming out of The Garage--Jason Grimes' shop in Lebanon Junction, Kentucky. We've covered some of his customer builds as features, plus we've followed along as he's created some interesting suspension setups. Well, he's at it again.
With the body of the '34 Plymouth...
With the body of the '34 Plymouth in the background, Jason already created his own custom framerails before the work on the suspension begins. He has also designed and built an X-member for the frame before tack welding the whole setup to his surface table, but then removed the X-member for easy access for other components.
This time Jason, who happens to like the way quarter-elliptic springs look and work, put his know-how into triangulating a set of those springs with a tube axle front suspension. As always, he works out his theory on paper first, then as a 3-D model in cardboard to see if his ideas have merit. Once satisfied with the outcome, he starts fabricating the necessary parts and pieces.
This particular suspension is going under a '34 Plymouth coupe, for which he has already created a set of custom framerails. The spring he's using is a set of quarter-elliptics from POSIES, but he basically builds everything else he needs himself. So follow along and see how it's done!
Here's a drawing Jason made...
Here's a drawing Jason made showing if he keeps the top bars of his triangulated design at 20 degrees from the springs, it will keep the axle centered without any major binding of the bushings (either in the bars or in the springs) when the suspension moves up and down.
Once the frame was squared...
Once the frame was squared and tacked to the surface table, Jason could begin work on the triangulated quarters. The bolt located up top will hold the modified radius rod in place while the holes in the frame are where the POSIES quarter-elliptics will attach.
Jason begins by fabricating...
Jason begins by fabricating a bung (a -inch piece of 0.250-inch tubing, drilled and tapped with -18 threads) that will be used to adjust the quarter-elliptics once they're in place.
A small section of the 3/16-inch-thick...
A small section of the 3/16-inch-thick top 'rail is fabbed and then drilled to accept the bung.
With the adjusting bolt in...
With the adjusting bolt in place (so the threads don't warp during welding), the bung is welded to the top 'rail piece.
After the top `rail section...
After the top `rail section is welded in place, the "ears" are heated with a torch and hammered down to meet the leading edge of the framehorn.
With a little bit of grinding...
With a little bit of grinding to clean up the welds, you should get something that looks like this. After the quarter-elliptics are set in place, it's time to mount them to the axle.
Another one of Jason's drawings...
Another one of Jason's drawings shows he'll need to figure in the 7 degrees of caster at the kingpin when there is a load on the spring. He's aware the spring will "grow" under load (a momentary stretch of the wheelbase), but the movement should be minimal.