How do you tell if leaf springs are good?

[XH29N0G]

What is the procedure to tell if the original leaf springs (on the car) are still good and not sagging too much? 

Are there specific measurements that can be made?

[fy469rtse]

Good question, service manual has a height for front , ? Is there a mention for rear,
They sat up a decent height from new, ? With weight on the car ? Are springs still arched or are they flat to look at from side of car, when they flatten out, back hangers will be angled back

[myk]

I still think it's a matter of preference.  If you like the way your car sits then the springs are fine, assuming of course there are no broken or missing leafs...

[HPP]

Are they bottoming out when driving? Do they wrap up and bounce during a high rpm launch? Either of these are dead give aways.  Yes you can check spring rate, load rate, and installed height, but they need to be removed for any of those.

There are ride height specs for the rear, but they are a rarely published spec that you will not readily find in any current mopar service or performance manual. They are deeply buried in some of the OEM factory spec sheets. I've only ever seen them once. I believe a copy is somewhere on the Hamtramack historical site. Overall, if your car sits where you want it and you don't have wrap or bottoming, you are okay.

[XH29N0G]

Are they bottoming out when driving? Do they wrap up and bounce during a high rpm launch? Either of these are dead give aways.  Yes you can check spring rate, load rate, and installed height, but they need to be removed for any of those.

There are ride height specs for the rear, but they are a rarely published spec that you will not readily find in any current mopar service or performance manual. They are deeply buried in some of the OEM factory spec sheets. I've only ever seen them once. I believe a copy is somewhere on the Hamtramack historical site. Overall, if your car sits where you want it and you don't have wrap or bottoming, you are okay.

I have no obvious problems with them, but I do have some issues with driveline angles and a thought hit me that if they were sagging, this might effect the driveline angles.  (I also have changed the transmission to a Tremec which is a much more likely reason, but I thought I would ask). 

[myk]

I'm certain that the only thing that can be out of adjustment with the rear end and its springs is the thrust angle; that is, are the wheels and the rear axle pointing straight ahead or are they off by a couple degrees or more.  Hotchkis for example sells thrust angle washers/spacers so you can adjust the thurst angle, but AFAIK there is no range of movement that's possible even if the springs are fully compressed from sagging or range of motion.  Someone correct me if I'm wrong...

[HPP]

In their installed position, the factory spring specs will appear to be almost flat. They do have a very slight arch to them, maybe 1.5-2" max. To most guys, this will appear to be flat. If you check it with a tape or string line, you can see they do have a slight arch. If they were sagging, they would have a slight impact on drive line angles. The same if you lift the rear up significantly. In general, the factory set these up with very minimal adjustments. They can be tweaked slightly and usually the two biggest offenders are thrust angle and pinion angle. There are shim kits to alter both of these angles if you find they are off.

[XH29N0G]

In their installed position, the factory spring specs will appear to be almost flat. They do have a very slight arch to them, maybe 1.5-2" max. To most guys, this will appear to be flat. If you check it with a tape or string line, you can see they do have a slight arch. If they were sagging, they would have a slight impact on drive line angles. The same if you lift the rear up significantly. In general, the factory set these up with very minimal adjustments. They can be tweaked slightly and usually the two biggest offenders are thrust angle and pinion angle. There are shim kits to alter both of these angles if you find they are off.

Thank you.  This gives me something to check.

[rt green]

pinion angle should be 2 degrees down. new leaf springs are cheap enough so if yours are in question, replace them. it'll ride better too.

[XH29N0G]

pinion angle should be 2 degrees down. new leaf springs are cheap enough so if yours are in question, replace them. it'll ride better too.

I have my pinion angle shimmed presently, but without a shim it was 1 degree (nose-front) down.  I did not think that the springs would change that much.  Thanks for the reply.  I am going to look at them some more shortly.