Spring Stack Shift 66

[Peter M.]

I have a stock original F41 optioned 66 427 Coupe with original rear spring and liners. The rear spring stack has shifted (leaves are out of line) so that the drivers side upper leaves seem to fan forward while the passenger side fans toward the rear. Is this due to torque and are the 4 main anchor bolts and anchor plate sufficent to stop this condition? Do the grooved liners hold them in place?

[Joe L.]

Re: Spring Stack Shift 66

Peter-----

The combination of the spring retainer bolts and the spring liner raised edges serve to maintain the alignment of the spring leaves on a 64-79 Corvette, since NO spring end bands were ever originally used on these cars. A LITTLE bit of "misalignment might occur in service, but it shouldn't be very much.

Check to be sure that your spring retainer bolts are, in fact, 9/16" bolts. The quickest way to do this is to check the differential rear cover casting number. If it's 3871375, then you have the 9/16" bolts as you should. However, if it's 464910, then you have a GM replacement cover which uses 7/16" bolts. When this cover is used with any 63-77 Corvette with a 2-1/4" wide spring, spacer plates of GM #459032 (discontinued) MUST be used on either side of the spring center section to prevent exactly the problem which you described from occurring.

[Peter M.]

Re: Spring Stack Shift 66

Thanks Joe - I have all original differential and related components so I think the key here is worn spring liners. Do you have a recommendation re best supplier for correct liners or are they all the same.

[Gary B.]

Re: Spring Stack Shift 66

Peter,

GM still makes the liners for your spring and these are generally considered the best available. They are GM part # 3794113 and the GM list prices is a steep $12.25 per liner. Your spring originally came with 5 liners.

You'll have to cut the liners to length. I don't know if you can get away with buying 4 liners and then use the cut pieces from one liner to create the shortest liner. If not, you have to bite the bullet and buy 5 liners.

Gary