Topic: Rear spring issues B2 springs on a convertible

[droptopboss]

I'm starting to put my 70 convertible back together. I was hoping to improve the handling so I bought what are supposed to be BOSS 302 springs front and rear and the BOSS sway bar. Well I sat the car on the floor the other night and it looks like a 4x4. There is no drivetrain in it yet. I have about 6.5 inches of clearance between the rear tires and the lip of the 1/4 panel. I loosened everything up and unhooked the shocks and bounced it the best I could, nothing. It is also 1/2 inch higher on the driver side than the passenger. I was so happy to be making progress again, now this. I want to pull my hair out.

What did the Shelby convertibles use for springs?

[Bob Gaines]

I'm starting to put my 70 convertible back together. I was hoping to improve the handling so I bought what are supposed to be BOSS 302 springs front and rear and the BOSS sway bar. Well I sat the car on the floor the other night and it looks like a 4x4. There is no drivetrain in it yet. I have about 6.5 inches of clearance between the rear tires and the lip of the 1/4 panel. I loosened everything up and unhooked the shocks and bounced it the best I could, nothing. It is also 1/2 inch higher on the driver side than the passenger. I was so happy to be making progress again, now this. I want to pull my hair out.

What did the Shelby convertibles use for springs?

The convertible 69/70 Shelby used the same as fastback 69/70 Shelby in the rear and regular Mustang springs (for application)in the front.

[sgl66]

There is no drivetrain in it yet. I have about 6.5 inches of clearance between the rear tires and the lip of the 1/4

Springs have what is known as a load rate. You need the weight of the drivetrain and convertible parts installed before getting an accurate measurement.

This may help explain http://www.eatondetroitspring.com/spring-rate-vs-load-rate/

[droptopboss]

I understand that I need the weight on the car to find out where it's going to end up for height. I'm not so worried about the front end, it's the rear I'm worried about. The convertible parts don't weigh that much, less that I do I'm guessing (215#). I know gas tank, deck lid, bumper, etc... Still not that much weight. I stood in the car and it doesn't budge.  How much more does the rear of a B2 weigh than a convertible?

The other problem is it's leaning to passenger side by a 1/2 inch front and rear. I had a frame guy come take a look at it and he couldn't see where it's ever been hit. It has original 1/4s, front aprons, rockers. I had it up on a set of stilts for lack of a better term. They were mounted on the front bumper bolts and the front mount of the leaf springs and it sat level then.

[midlife]

I wouldn't be too concerned until you've added the engine and interior and drove it a few miles.  It takes that long for a suspension to yield to the forces and settle to its nominal position.  All suspension parts should be tightened with full load on the wheels.  Until then, snug everything up and install all the parts, and you'll find the suspension has dropped an inch or more.  Then go for a ride around the block 2-3 times.  When you come back, you'll find the suspension has dropped quite a bit.  Get under the car and torque everything to spec.  Until then, you can't be sure of an offset from side to side, as it could be due to how you tightened the suspension bolts without the proper weight distribution.

On my 66, it was 4-6 inches above nominal until I installed all parts, and it dropped only 2 inches.  I took it for a 2 mile drive, and it was within 1/2" of where it should be.  I was concerned as well, but everyone including Eaton said not to worry.

[sgl66]

I wouldn't be too concerned until you've added the engine and interior and drove it a few miles.  It takes that long for a suspension to yield to the forces and settle to its nominal position.  All suspension parts should be tightened with full load on the wheels.  Until then, snug everything up and install all the parts, and you'll find the suspension has dropped an inch or more.  Then go for a ride around the block 2-3 times.  When you come back, you'll find the suspension has dropped quite a bit.  Get under the car and torque everything to spec.  Until then, you can't be sure of an offset from side to side, as it could be due to how you tightened the suspension bolts without the proper weight distribution.

On my 66, it was 4-6 inches above nominal until I installed all parts, and it dropped only 2 inches.  I took it for a 2 mile drive, and it was within 1/2" of where it should be.  I was concerned as well, but everyone including Eaton said not to worry.

+1

[droptopboss]

OK.  I'd still like for a few more people to chime in on this. I don't want to be tearing this thing back apart with new paint on it. I was supposed to go in for paint Sunday and backed out because of this.