Hot Rods Chevy 3100 Straight Axle upgrade options?

you might could rig up something like this


I have had axles straightened at truck shops here in Al
there has to be a shop that can do this in your area

 

I'm running the stock axle on lowered springs. My caster is shimmed and perfectly fine. It is the camber that is an issue. Nobody wants to bend the axle to make the tires lean in which is ideal for radials. The only shops equipped to do it are only used to working on large commercial trucks and don't want to work on a 66 yr old 1/2 ton.

 

The "max caster, min camber (0), min toe-in (approach 0")" are general rules that can be followed on almost every vehicle, even if the particular numbers for different vehicles might not be exactly the same. BUT, I should also mention that these orientations might work better with tires which have a "normal sidewall height" rather than some of the more recently popular "short sidewall" tire/wheel combinations! The wider the tread, shorter the sidewall, the more critical that camber will become if it's not at or near "zero", to result in good tire wear across the tire's full tread width.
Are you having problems with thread wear on the inside or outside? Camber doesn't result in your rough ride. Loose king pin bushings' bad ball joints, loose steering box, bad tie rod ends could all have something to do with your slight bump steer. There are hundred of people on this site that have changed to radial tires on a stock camber I beam and rave about the handling. Try a heavy duty steering damper to help with bump steer.

 

My '37 is a little lighter and narrower then your truck, but still the same basic frame and suspension. Mine has a stock axle under the front with custom made leaf springs from Detroit Eaton spring. I changed from the stock 216 engine to a 250 inline six, which is much lighter in weight. This made for a very harsh ride. I had been running stock '37 springs with 4 out of the original 7 leaves. I also had teflon type spring liner, all new shackles and all new steering pieces. The truck rode ok but I was worried about the reduced number of springs and the fact that they were 79 years old.
To figure out what was needed for a softer ride, I borrowed a set of digital scales and set about weighing the truck. It was full of fuel and had two people inside, just as driven conditions. I weighed all four corners on separate scales. I then unhooked the front shackles and shocks and weighed the axle, tires brakes, 1/2 the springs, and sway bar to find the unsprung weight, I did the same for the rear. Eaton now knew sprung and unsprung weight, front to rear weight, and side to side weight. I then used one digital scale to figure out the front spring rate. Using two solid axles with steel bearings on each end running through the spring eyes, (think of a funning looking state board) I placed the scale in the center of upwards facing arch of the spring. I then lowered my Toyotas trailer hitch onto the scale and read the weight it took to compress the spring 1" and also 2". I did this a couple times and came up with a very close rate of 375 lbs per 1" compression. Stock springs for '37 were rated at 470 lbs pre 1" compression. Eaton made my new ones 275 lbs per 1" compression.
The truck rides much better now but still needs some different shocks. It drives as good as my '03 at any speed. Most highway driving is 65 to 70 mph. I have zero bump steer and run radials all around still with stock alignment specs. Caster will cure much of your steering problem , I see no need to bend on the axle.

Joe

 

I've got 215/70r15 on the front, so nothing super low profile (not personally a fan of lo-pros). I haven't seen any crazy wear, but have read about the stock camber being incorrect for radials, so had hoped to get that corrected along with a good alignment.

 

They look terrible there but those were a real nice set of 54 springs when I put them in and took the leaves out and cleaned up the springs. That does show right at 100K of mostly daily driving.
The problem when you remove leaves on the front of one of these trucks is that the keep sagging over time if you drive the truck a lot of miles. I started out with about three inches between the uncut bumper and the frame and over time it progressively sagged down to under 1-1/2 sitting flat. Add to that the caster is changing as it continues to sag. I'm just going on the experience of owning this truck for most of the last 45 years.

 

I suggest going back to the original leaf springs and remove one or two of the mid leaves. This will soften the ride. If you are running gas shocks I would replace with standard oil filled shorter shocks. If the shocks are too long then it ride like a rock if the shock is in a compressed state. Also Gas shocks are notoriously stiff.

 

Hmm don't know then and cant really help you cause honestly ive never heard of having to recamber an I beam because you have radials. I run radials on mine and never recambered it and it runs just fine. IF you got bumpsteer it most likely has something to do with your drag link. Id probably swap back over to stock springs and clean them up and get a drop axle done by sids. Beyond that I cant help you much then. You can call barry fleet services in Hempstead and see if they will bend axles as they do a bunch of big rig stuff.

 

with all due respect to all involved, talk with Sid at www.droppedaxles.com. He will answer all your questions regarding dropped axles, suspension, etc. I run one of his 4" dropped axles under my 50 with stock springs and I couldn't be happier. It handles and rides good. I've got alot of miles on my truck.

just my .02 cents
BigMike

 

pics please

thanks

 

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Did you make any mods to the steering in order to make the setup work without bump steer? I'm wondering about modding my steering arm for now to get the bump steer improved at least until I can afford a SIDS setup.

 

use modern ball joints, make sure pitman arm is parallel to the ground (this is important). I have a 73 Chevy two wheel drive steering box mounted on the outside of frame, raised to keep my pitman arm parallel. I did add a small dampener behind the axle( so you couldn’t see it). I have little to no bumpsteer. I can comfortably cruise at 70 with no worry of changing lanes on its own.


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With all due respect for the site, I've had and modified several of these trucks with dropped axle, GM subframe and MII style front end.
The stock setup is such a compromise when the other, more modern options result in a better handling and riding truck.
They are some work but the cost isn't that bad. I mean, you had the money for a 400 hp engine...dropped axles and springs aren't cheap either and you still have an old gearbox.
Lots of good advise has been given.

 

Of course it will. No one will deny that. There are many things you can do. Not all that you should do. IMO.

 

It just depends on what a person is willing to put up with to stay "traditional".
While I love traditional hot rods and have built and owned several, I'm all about how well they drive.
All of my '32s have a Vega box with cross steer. One finger steering at 70 mph.
No old school F1 or Mustang box.
Again, a personal choice.

 

"HAD" being the operative word here. With a baby on the way and a house full of needed repairs, a hotrod is a luxury. If there's something I can do with minimal cash that makes any improvement in the ride/handling, that's what I aim to do. If I had an extra $3k to blow on a quality MII setup, I wouldn't be asking about other options.

 

Thanks for all the advice guys. I am leaning toward rebuilding the stock springs and putting them back on to improve the ride and steering geometry for the time being. Having it drive correctly is more important to me than having it lowered at this point. The dropped axle setup can come later. I installed the monoleafs with my dad when I was still a kid. It looked really cool, but now that I have more understanding of the subtleties involved in the steering and suspension geometry, and now that those monoleafs are almost 20 years old, they're less impressive. I also might consider putting some beefier tires on the front end as cash permits. There are a lot of very bumpy roads in my neighborhood. They're currently 215/70r15, but thinking a size or two larger couldn't hurt, and they'd still be smaller than the rears which are 255/70r15.

 

Coil springs is an option that probably has not been mentioned. You can use radius rods or a 4 link setup if you like.

I have seen them also setup with coil overs although that would not be on my list of really cool things to do.

To get your camber set the way you want it set send the axle to Sid's in OK. Those guys got it goin' on.

 

Just rebuilding the stock springs, installing strips in them, will make them operate more smoothly. Cheap, too.

 

I' d drive my 55 2nd series cross country after my straight axle upgrades.
dropped axle...Posies Super Slider springs...sway bar (front and back)...Bilstein Shocks (front and back) and yes there WELL worth the money.

 

Just curious, did you do the bilsteins at the same time as all the rest of those mods? Or did you get to see what it was like with regular shocks first?

 

Thank you. That is a cool shot of the setup to do the job.

 

Had Monroes. Threw em straight in the garbage after installing Bilsteins.

 

If the roads around Houston aren't any better now than they were were about 5 years ago, the last time I was out there, even a damn Rolls Royce would ride like a log truck! Anything over 35 mph was like taking your life in your own hands, bumps, dips, holes, uneven patches everywhere. There was one street, can't remember the name of it right now, it led down to an older port/industrial area, anything over 15 mph would throw you out of the seat.

 

Wider tires will make for tougher steering, so go taller and not much wider. You can run a little less air in a taller tire to take out some road vibrations.

 

Sid's dropped the axle on my '53 dodge 3" and did an excellent job, I also purchased new leaf springs from McVeigh's removed the second to the shortest leaf and reversed the spring eyes to get the front end down 6". New king pins, shackles, tie rod ends and shocks. No bump steer and rides fine.

 

Since everyone covered all the front spring rates I'd like to suggest check the springs in your seat..lol
Riding in my t-bucket then getting in my buddy's 33 with a Glide Ing. seat was like heaven on earth, what a difference!

 

one thing that should be mentioned when using a dropped axle is watch the scrub line of the rims and tires. nothing worse than getting a flat front tire traveling 65 mph and can't steer due to the truck is riding on the axle. I would suggest 16" rims, not 15's.