68 trailing arms

[david ferragamo]

wanted to ask about the difficulty level of replacing trailing arms,leaf spring,and bushings on my 68 small block convertible. the car has new rotors and calipers. I have not checked the emergency brake yet, but it works. I was thinking of a #340 composite spring,and would have the new arms rebuilt by a profesional. Thank you guys for any suggestions

[Joe L.]

Re: 68 trailing arms

David-------

The service operations about which you inquire are not really all that difficult to perform. Of everything you mentioned, the hardest part is installing the trailing arm forward bolts. To do this, support the arms with blocking, attach thin fishing line through the cotter pin hole, and, using a wire leader for the fishing line, pull the bolt through the frame holes and trailing arm bushing.

Personally, I do not recommend the use of composite springs on any C2 or any C3 not originally equipped with such a spring, but to each his own.

[Bob I.]

Re: 68 trailing arms

David I've talked to people who have installed such a spring and were very unhappy.I recently rebuilt my suspension and used a 196# stock spring rate. The ride quality is great. When you change your spring, be sure to put weight on the spring before tightening the bolts that attach the spring to the rearend cover to avoid cracking the cover.

[David M.]

Re: 68 trailing arms

David, My 2 cents, I just did most of the rear end in my 68, 327 roadster. Its not a job for a shade tree mechanic with basic limited tools. There are a few tricky things that even a seasoned wrench like myself had some trouble with. But, with the right service manual, tools, patience, many parts catalogs and this web site (thankx Joe and others), I was able to get through the procedure with only basic usual (Murphy's law) problems. Use the best quality parts(Spicer, GM etc..), inspect everything, don't order anything until you have it all apart, expect to replace everything. I will gladly answer any Q's you may have. Remember the most important item when you do any chassis/suspension work is SAFETY.

[Norris W.]

Re: 68 trailing arms

You're going to need to inspect the rear end itself also. Rear suspension and rear yoke wear are a double edged sword that prey on each other. The more the suspension sags and the rear camber changes, the more the yokes wear because of the increasing pressure, and the more the yokes wear, the more the camber changes. In/out play on the yokes SHOULD BE almost non-existant. For the above reasons the wear graph is sharply upward. I had one come in the shop several years ago that had worn bad enough that the ends of the U bolts had cut the housing to the point that the seal was out on one side and there was nothing left to hold it. We've had several over the years that wore to the point that the clips no longer had a groove to seat in and the clips were loose in the gear oil.

An easy way to look at the slop in the yokes is to support the car by the chassis, unloading the suspension with the wheels off the floor, then lift up under the wheel with a lever, even a 2 X 4 and have somebody look to see if the yokes are moving significantly.