How flat should loaded leaf springs be?

[leakyfawcett]

Hey everyone,

I have a 1971 3/4 ton 4x4 Suburban. The leaf packs are pretty flat when loaded, and the truck is sitting there. They obviously droop a lot when I jack the truck up by the frame...

My question is this, should the springs be bowed downward when the weight of the truck is on them? I just don't know whether these springs are totally worn out, of if flat is pretty much how they're supposed to be.

Any help is much appreciated!

[Altec]

Front, or rear? The fronts will be close to flat. A reverse arch is a worn spring. The rear can flatten out a bit with load. Is it sitting on the overload spring?

[swamp rat]

My fronts on my 4wd were slightly reversed before i changed them out, rears have a definant arch.

[Blazer1970]

Stock front springs will have a noticable negative arch with the truck weight on them. 2inch lift springs sit about flat.

[leakyfawcett]

Hmmm... well they're definitely not reversed. The fronts actually have a little arch to them, but the P/O added some leaves to it I think, to make a home-brewed lift.

I'm more concerned with the rears. Below are some shots of the right-rear, with a jack stand under the axle (bearing the weight of the truck).

The pack as a whole doesn't seems reversed at all, but the ends of the main leaf seems iffy to me. You can kind of see it in the second pic. Just don't know if I should be comfortable cleaning and painting these, or if I'm better off looking for a replacement set.

Thanks!
james

[special-K]

They must be worn. My question is "How much load?" It should take quite a bit to flatten them out,like 1500# or more. It looks like those are on the stops now. That should take a lot of weight. A whole lot. They must be tired.

[leakyfawcett]

That first photo is misleading, they're not at the bump stops yet. And when I say "loaded", all I mean is the weight of the truck is on them, not having jacked the truck up at all.

They look flat like that with the Suburban empty, resting on all four wheels.

[Altec]

Those are without a doubt worn out lol. They are sitting on the overload, and the bent ends are no good.

[leakyfawcett]

Alright, thanks for all the input everyone... I think I knew they were worn out, just hoped they weren't...

Now to figure out whether to find aftermarket replacements, or try to make something from a later model truck work...

[special-K]

Yeah, I was looking at that main leaf and it is way tired...shouldn't have that negative bow at all. The springs should have decent arch with truck on all fours,even with a good bit of payload. You should be able to find a take-off set of leafs from someone lifting their truck. Maybe talk to any places that sell them and leave info. Most just want to toss them not wanting them laying around. Is there a spring shop near you? They may feel yours are rebuildable or can offer a reasonable solution. I'm replacing the springs on my '72 but shipping the originals would be costly. They may be pretty worn,also. I know the fronts have serious sag. They sit about on inch from the bump stops.

[leakyfawcett]

I'm considering a 4" lift kit with all four springs, although I'm not sure if I think that'd be overkill for me. I'm not making a real off roader... I'll only be running roughly 32" tires. I don't think I saw any 2" kits that included all 4 springs.

[rayfinseats]

When you say "loaded" are you talking about you or the springs?