The Stovebolt Site Forums The Shop Area Driveline 1/2T vs 3/4T Suspension

I have a 1962 C10 1/2T. It has the torsion bar front suspension, and coil springs in the back.

Aside from the obvious axle differences (6 vs 8 lugs), what are the differences in the actual suspension components?
I know the coils would be an easy swap in the rear. What about the front? Is it a new set of torsion bars? Did they do something different?

I am wondering how difficult it would be to upgrade the suspension on the 1/2T to 3/4T standards. Not trying to make a 3/4T out of it, just beef it up a little.

My manual suggests front torsion ratings of 1250lbs for both 1/2 ton and 3/4 ton. There was an optional 1500lb front torsion spring for both. Rear coil ratings of 1250lb for 1/2 ton and 2000lb for 3/4 ton.
The GM heritage manual details additional spec ratings, but does clearly suggest fronts are the same and rears are different.

Before trying to make a 3/4 ton out of a 1/2 ton also consider frame and other suspension components, are they the same? If different then adding stiffer springs might lead to early failure of other parts?

Is there a compelling reason for putting 7 1/2 pounds of potatoes in a 5 pound sack? Very few antique "1/2 ton" pickups see much more load in the bed than a Yeti cooler iced down with a max load of Bud Light on tailgate day!
Jerry

Compelling reason is putting 800 - 1000 pound motorcycles in the back when they need to be "rescued". I have done this several times recently. The old truck really squats when I load it up. I know I am still within capacity, but was looking to beef it up a bit. Not trying to make a 3/4T out of it, just give it a bit more gusto.

It's not something I would do on a regular basis, but nice to know it can.

It would be a lot simpler to fit a set of air bags inside the rear coil springs, and air 'em up when a little more capacity is needed. Otherwise, buy a good kidney belt and be prepared for a rough ride all the time. The same thing could be accomplished with air shocks, but they have a bad habit of overstressing the upper and lower shock mounts, and they require much higher air pressure to carry the same amount of extra load.
Jerry

I think I remember seeing "helper" leaf springs that were basically half a leaf spring that bolted to the frame behind the rear axle, but didn't normally interact with the rear suspension.

When the load exceeded a certain level, the frame lowered enough that the spring contacted the trailing arm and provided additional support.

Does anyone else remember these?

Trailing arms thickness and lengths are the same for short and long bed 1/2 and 3/4 ton to my knowledge.

I recently upgraded to 3/4ton springs in my '63. I'm so happy with the result. I didn't notice that much change in the ride (probably because the front springs are so broken in). I use my truck to load up 600-1000lbs of firewood regularly sometimes getting pretty close to the bumpstops (worn out rear springs too, I'm sure). Now my truck doesn't squat nearly as bad as before.

I would recommend ordering a new pair of rear 3/4ton springs through rockauto and installing them. They aren't that expensive, and installation isn't that difficult if you take your time and have some jackstands. If the ride is too rough, you can just put the old 1/2 ton springs back in.

What Pratt said or on the new springs remove a spring or two.

"Remove a spring or two"- - - - -I'd like to hide and watch you do that on a coil spring. I've got a 72 Chevy 1/2 ton with rear trailing arms, coils, and helper springs. They are quarter-elliptical leaf springs bolted to the frame that contact the rear axle housing as the suspension travel approaches the bump stops. Chevy used to sell a "Camper Special" option with extra weight capacity, but I believe that one was a 3/4 ton.
Jerry

Those so-called "helper" leafs, have come on every 60-something C10, and C20 I've ever owned. They're half-leafs, or progressive-leafs. Anyway. They make NO interference with your ride. It rides exactly the same loaded, or empty. I can't say enough (good) about 'em. By all means, if you can get a pair of them. Do it. You'll never regret it!

Chris