Rear Spring Assembly

[Michael M.]

I searched the archives but couldn't find my answer there.

I am replacing the rear spring on my '68. I just received my new rear spring and I disassembled to paint it.

When I re-assemble the spring I typically use c-clamps to hold the spring together, then install the center bolt and tighten it.

My question surrounds how tight I should clamp the leaves together. When I disassembled the new spring, I clamped the spring together to remove the center bolt and noticed that the spring was not clamped 100% tight. As I tightened the c-clamps to disassemble I noticed that there was about a 1/4" to 1/2" of compression of the leaves before it was fully tight. This left a gap between the nut on the center bolt and the bottom leaf of the spring.

So how tight should the leaves be clamped together? If it is clamped too tight does it negatively affect the operation of the spring? If too tight, will it prematurely wear the leaf liners? Thanks for any replies.

[Michael G.]

Re: Rear Spring Assembly

This bolt is more of an alignment tool and keeps the leaves from shifting. It is not neccessary to snug up until after the spring is installed. You should have it drawn up enough that the leaves cannot shift during the installation. Since you have been to the archives, I assume you saw the precautions that we discussed recently involving the rear spring. Especially the issues with the use of new hardware (taller head on the bolt you are inquiring about and slightly longer mounting bolts that could crack the differential housing.

[Michael M.]

Re: Rear Spring Assembly

Michael, I guess that makes sense. The leaves are going to get compressed anyway when the bottom mounting plate is torqued to spec. So should I not worry that the center bolt is loose after installing the spring? It really can't be tightened after the spring is installed because there is no way to hold the top of the bolt to prevent it from spinning.

I am using the Paragon mounting bolts and center bolt and have had no issues. I recently rebuilt my rear suspension, but stupidly didn't realize my rear spring was sagging (even after disassembly and re-painting). So here I am replacing the spring again. I also know not to torque the four spring mounting bolts until after the weight of the car is on the suspension.

[Michael G.]

Re: Rear Spring Assembly

I'm sure we all have done this somewhere along the way of our restorations. Unless the center bolt is coated and has some resistance of the nut turning, there should be enough tension from the many leaves wanting to pull in different directions to hold the bolt enough to just snug it up. Not a big issue as you know since the mounting bolts do all the work.
I hope you dont't find, as I have, that the new spring is now holding the rear end of the car too high. I had to take the main leaf (bottom leaf) from the new spring and use it with other eight of my original spring.

[Michael M.]

Re: Rear Spring Assembly

Thanks again for the reply.

Yes, I am a little concerned about ride height issues, but I'll install the new spring as is and see what happens. My car is a driver, so if there is an issue initially I am hopeful it may settle down a little over time. We'll see.

[Terry M.]

Re: Rear Spring Assembly

What Michael Gaither found about ride height is unfortunately the case with most, and maybe all, reproduction rear springs. The solution he chose is also the easiest.

[Jamie F.]

Re: Rear Spring Assembly

Should the center bolt be installed with the nut on the bottom or top?

[Terry M.]

Re: Rear Spring Assembly

Nut on bottom

[Jamie F.]

Re: Rear Spring Assembly

Thanks Terry!