Last Updated: 10/9/98
Air Shock Upgrade

When Jet Industries converted the Omni/Horizon chassis to an electric vehicle they drastically increased the rear axle loading.  To compensate for the extra weight they used custom wound heavy duty coil springs on the rear struts, and added helper springs.  The helper springs are mounted between an added steel angle section connecting the two suspension trailing arms and a steel angle frame mounted under the rear floor.  The early 007s used helper springs made from Subaru 600 van shock absorbers with coil springs WELDED onto them.  This shock can be recognized by the spindle type mount at the top, and a loop type mount on the bottom.  The later 007s use a Chrysler Lebaron front shock, also with a coil spring welded onto it.  This style shock has spindle type mounts both top and bottom.  Both of these coil over setups suffer from the same basic design flaw.  The shocks are mounted at a 45 degree angle.  As the suspension deflects, the shocks must rotate on their mounts.  Spindle mounts cannot rotate, so when the shock reaches the limit of its deflection, it bends the shaft.  On the next deflection the shock jams, and something has to give, so the axle bends.  Eventually, the axle cracks.

My car had a broken axle when I bought it, though I didn't know it.  While towing it home, the right rear wheel suddenly bent over at a 45 degree angle and blew the tire.  What a fun way to spend an evening.

I replaced the broken axle with a used one, and proceeded to attempt to find a better solution to the shock problem.  After going through several catalogs, and bringing home and returning about 10 air and coil over shocks, I arrived at a workable solution.  I am sure it could be done better, but it works for me.

What I did was remove the silly Subaru shocks and fabricate brackets to mount 1963 Corvette air shocks.  They have loop type mounts at both ends so they won't bind when the suspension deflect.  They are longer than the original shocks, so I had to mount them angled front to rear rather than side to side.  Here are a few pictures of the installation.

(Click on any picture for a closer look.)
 As you can see, it is not an overly complex installation.  I simply made brackets out of steel angle and bolted them to the axle beam.  The upper shock loops are bolted to the frame under the car floor using 7/16" bolts, and the lower loops are mounted on the angle brackets using standard shock mounting bolts.  I did have to modify the shocks slightly.  The lower loop has a steel sleeve that was to long, so I cut them off even with the bushing.  Also, these shocks have the loop ends canted slightly out of true.  This required the lower mount brackets to be bent at a slight angle to compensate.

I have been using this setup for over a year now, with no problems.  Two other Jet 007s in our EAA chapter have also been fitted with the same system.  The added dampening effect of the extra shocks really helps the car handle the extra weight.  If I had time I might be tempted to redesign the mount.  The shocks would probably work better if mounted side to side, but that would have required building far more complex lower mounts.  Also, there just might be a more suitable shock out there that would do better.  Meanwhile, what I have works.
 

If you have any questions about my car please e-mail me.
Send e-mail to Mike Chancey at:


Return to Homepage