1953-62 Front Suspension Special Tool


The front suspension of the 1953-1962 Corvette is similar in design to the one used on the 1949-1954 Chevrolet passenger cars. As a matter of fact, most of the parts are interchangeable. This independent front suspension design uses is similar length control arms, tubular shock absorbers within open coil springs, reverse Elliott-type steering knuckles and king pins.


Servicing the components of this suspension is not too difficult as it is a conventional design and most of the tools and equipment available today will handle the various parts of the job. Replacing the upper, inner shafts, however, will cause a problem.


Please see the phantom view of the upper control arm shaft. Note that the shaft (3) is a continuous steel shaft projecting out of each side of the spring housing (1). I have labeled several of the parts of the assembly as noted: (1) Spring Housing (front frame cross member); (2) Control Arm Bushing; (3) Shaft; (4) Rubber Seal; and (5) Control Arm.


The control arm bushing (2) is a nut-like device, which screws into the control arm (5) with an interference fit. (An interference fit is one wherein the parts are machined to be fitted so tightly as to stay in the assembled position during the service life of the assembly without other means of locking said parts together.) After it is screwed into the arm, it will not turn again. The inner threads of the bushing, however, form the actual moving part with the threads of the shaft allowing for the up-and-down movement of the front wheel.


The threaded fit between the shaft (3) and the spring housing (1) is also an interference fit, and after installation, will not turn again. This is the part we will talk about removing and replacing.




I mentioned that there is a problem when trying to replace the upper, inner control arm shaft. Read on and let me explain why. There is a special tool shown on page 3-16 of the "Corvette Servicing Guide" which I feel is absolutely necessary to do the job. It is called the Upper Control Arm Shaft Removal and Installer J-2958. The removal of the old shaft is possible without the tool because damage to the shaft is not important since the old part will be discarded. However, the new shaft must be installed without damage, and since there are no wrench flats or screwdriver slots on the new shaft, it becomes necessary to have a special tool with which to grasp the new shaft and forcefully screw it into the spring housing. This upper, inner control arm shaft, as we have mentioned, is a hardened steel shaft with threads on either end and is screwed into the spring housing with great force so it will remain solid and not be able to turn in the housing during use. As you can imagine, over a period of years, wear will cause looseness between the threaded shaft and the bushing, this wear necessitates the replacement of the shaft and the bushings during an overhaul.


The special tool (J-2958) used by Chevrolet was a means of gripping the threads of the new shaft and providing wrench flats with which to drive the new part into the spring tower and all the while doing no damage to the threads on the shaft. The procedures are very clear in the Servicing Guide, so I won't go over them here. My idea, as you might have guessed, was to make a tool to replace J-2958, which is no longer available.

















To make the tool, I used the old shaft and bushings and cut them into the parts shown in photo #1. I used an abrasive cut-off saw to do my cutting since the pieces are hardened and cannot be cut with a hack saw. Using this saw I was able to cut the parts in such a way as to form the parts of the tool. They have the correct thread, of course, so they will screw onto the new shaft, locking into place just like tool J-2958 did. Photo #2 shows the approximate size of the various parts. Photo #3 shows the tool assembled and ready to screw onto the end of the new shaft.


The new shaft screws into the long tubular nut about half way. The short stub shaft screws into the long tubular nut from the other end and butts into the new shaft. The lock nut then screws onto the remaining part of the stub shaft to lock the assembly together so that it will allow the wrench flats on the lock nut to be used to drive the new shaft into the spring housing to the desired depth.


After the new shaft has been driven to the proper setting, the individual parts of the tool are simply removed.


If you plan to do this job be sure to follow the directions in the "Corvette Servicing Guide" as there are several places where serious mistakes could be made by not knowing the particulars of the job.








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Front Suspension.pdf



 

CORVETTE TIPS AND TECHNIQUES

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Photo #2

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