Suspensions, suspensions, suspensions! Sometimes it seems like the only tech stories we do here at CLASSIC TRUCKS are chassis and suspension related. Then again, there's good reason for our bias. Most vintage trucks are in need of some sort of suspension attention, whether it's freshening up the stock stuff or scrapping all of it in favor of modern underpinnings.
Yet with all the chassis tech that makes its way into these pages, surprisingly little of it has to do with straight-axle front suspensions. There's a pretty good reason for that, too. Based on what we hear from our readers and what we see at events, independent front suspensions are high on the wish lists of most classic truckers. Most, but not necessarily all.
Let's face it, not everyone has the financial wherewithal or fabrication skills to dive into an aftermarket IFS install or subframe swap. Furthermore, there are some folks who would rather keep beam axles under their trucks--some for reasons of originality, and others who simply like the simple, rugged nature of the setup. Whatever the reason, there's certainly a need for beam-axle upgrade parts, and there's a wide variety of them available from the classic truck aftermarket.
Whether you want a lower stance, better brakes, improved ride quality, or easier steering from your beam-axle ride, the parts are available to make it all possible. Naysayers may point out that you'll spend nearly as much money upgrading the steering, springs, and brakes on a beam-axle truck as you would on an IFS conversion, and the end result still won't ride or handle as nice. There may be some truth to that, but it doesn't end the debate. Many suppliers we speak to say that beam-axle upgrades remain appealing because customers can spread them out over time--disc brakes to start, new springs a few months later, and so on. This not only breaks up the cost, but also means the truck isn't out of commission for weeks or months on end. And since most upgrades are bolt-on affairs, they appeal to hobbyists who may have limited welding or fabrication skills.
From our perspective, any modification that makes your straight-axle truck safer and more fun to drive is worthwhile. So we've taken the liberty of highlighting the upgrades we feel make the most sense. Think of it as a straight-axle wish list or a resource guide for making your classic cruiser more roadworthy. Take a look and see what you think, then get out to the garage and start whipping that classic into shape!
Fortify the Foundation
Whether you're working on a straight-axle ride or a vintage IFS setup, it's always important for the core components to be in good working condition before any modifications are made. It should go without saying that the frame and axle need to be straight and solid, and you'll want to make sure all wearable items like kingpins, bushings, and tie rod ends are in good shape. Any excessive wear will only be magnified by additional modifications.
Basic rebuild parts are available from any number of CLASSIC TRUCKS advertisers if you're unable find them at your local parts store. A number of upgraded wearable components are also available. Companies like Brothers, Classic Performance Products (CPP), and others offer heavy-duty tie rods, tie rod ends, and drag links for straight-axle trucks that are not only more durable than stock pieces, but are also better suited for upgrades like power steering and radial tires.
New kingpins and related components (bushings, etc.) can also be found from a variety of specialty companies. Of particular interest are the Royal Kingpin Kits from Stainless Steel Brakes Corporation (SSBC). These innovative kits replace the standard brass bushings with modern needle bearings for improved steering response, lubrication, and longevity. They also use hardened stainless steel kingpins, and most other parts in the kits are either stainless steel or chrome-plated for improved appearance and wear. Royal Kingpin Kits are available for '41-54 GM 1/2-ton trucks, and '37-52 Ford 1/2-ton through 1-ton trucks.
Goin' to the Disc-o
Here's a topic that we harp on a lot at CLASSIC TRUCKS, and we're going to say it yet again: If you plan on driving your vintage rig regularly, put disc brakes on it! Let's face it, you can be as careful as you want while you're out on the road, but you'll never change the driving habits of the jerk in the Honda who cuts you off right before slamming on his brakes for a red light or freeway exit. Having disc brakes on your classic's front axle will at least bring you up to par with the stopping power of most vehicles on the road.
There's really no excuse for not making the swap since companies like Engineered Components, Inc. (ECI), Stainless Steel Brakes, Master Power Brakes, No Limit, CPP, and many others have a variety of disc brake conversion kits and components available for popular Fords and Chevys. These range from simple setups utilizing later-model OEM equipment to high-tech arrangements featuring drilled and/or slotted rotors and performance- oriented aluminum calipers. Many kits give you your choice of Ford or Chevy five-lug bolt patterns, and a few Chevy kits (from CPP, Golden State Parts, American Classic, and others) can be had with a six-lug pattern for those who'd like to retain stock-style wheels.
Of course, when you convert to disc brakes you'll also need to upgrade your master cylinder. Most companies that sell disc brake kits offer bolt-in dual-chamber master cylinders with power boosters that fit in the original locations under the floor. They should also be able to help you out with proportioning valves, fittings, and other necessary hardware for such a conversion. A number of companies--Master Power, No Limit, Kugel Komponents, Industrial Chassis, and others--also offer specific-fit and universal firewall-mounted master cylinders and swing pedals, which some rodders prefer over frame-mounted units.
Manual steering wasn't really a problem when all our classics had skinny bias ply tires and drove on gravel roads. But combine wide radial rubber, hard concrete, and a tight parallel parking maneuver and all of a sudden you've got an aerobic experience that'll leave your biceps sore and your lungs aching.
If easier steering is part of your wish list, several options are available. OEM-style power-assist systems are available for resto purists, but many people feel that these power cylinder/control valve-style setups are a little clumsy and cumbersome. That's why aftermarket companies like No Limit, Golden State Parts, CPP, and others offer conversion kits based on more modern power steering boxes. Some of the more popular Ford and Chevy kits consist of custom brackets and Pitman arms that allow the use of late-model Toyota 4x4 power steering boxes. For '47-59 Chevys, CPP, Brothers, Tuckers Classic Pickup Parts, and others also offer kits that adapt '69-87 Chevy 2WD power steering boxes to the original straight-axle suspensions.
It's a Spring Thing
A better ride and slinkier stance are pretty easy to achieve with almost any straight-axle truck. It's just a matter of manipulating the stock parallel leaf springs.
Almost any quality spring shop can de-arch a stock set of leaf springs to lower your truck's ride height. They can also reverse the "eyes" at the ends of the springs to achieve (or exaggerate) the same effect. And since we're talking about multi-leaf springs, you can usually remove a few of the shorter leafs to soften up the ride and lower the height (just don't get carried away).
Of course, since we're talking about half-century-old springs, it's often a better idea to just start fresh with new ones. Many aftermarket companies offer custom leaf springs (both mono-leaf and multi-leaf) designed to lower popular Ford and Chevy models. Eaton Detroit Spring can build a set of custom leaf springs for just about any truck that ever came down an American assembly line.
Any spring discussion should also include a few words about shocks. Simply put, you can't achieve optimum ride and handling with old, worn-out shocks. At the very least, you'll want to replace questionable original shocks with fresh new ones. Better still would be to upgrade to premium-quality, performance-oriented shocks from manufacturers like Bilstein, KYB, QA1, or Doetsch-Tech. These companies may not always have listings for vintage trucks, but if you can give them some measurements from your existing shocks (extended height, compressed height, etc.), they'll often be able to find a match. Keep in mind, too, that if you're lowering your straight-axle suspension significantly, you may need to install a shorter shock.
Bend That Beam
Back in the days before subframing and Mustang II kits, one of the only ways to lower your truck's front end was to have the axle "dropped." The process essentially involved heating and stretching the axle ends to raise them, thereby lowering the vehicle. Like so many other blacksmithing and metalworking crafts, however, this one has fallen out of general practice. There's at least one holdout, though: Mor-Drop, in Oakland, California, is still offering the service to hot rodders and classic truckers in need.
A new and improved version of the dropped axle has recently come on the market, as well. Introduced by Mid Fifty F-100 Parts last year, this modern dropped axle is fabricated with a 2-inch tubular steel center section, CNC-machined steel ends, and laser-cut spring pads. (A detailed installation is shown elsewhere in this issue.) Mid Fifty currently offers 3- or 4-inch drop versions for '53-56 F-100s. The fabricated dropped axle concept appears to be taking off, as the folks at Classic Performance Products tell us that they hope to have '47-54 and '55-59 Chevy versions available by the time you read this.
Admittedly, this is just a brief overview of available straight-axle upgrades, but we hope it'll get you thinking about possibilities for your pickup. More information is just a phone call or mouse click away, thanks to the catalogs, tech lines, and websites of the companies listed in the source box at the end of this story. If there's something available for your beam-axle truck, these folks should be able to help you find it.
What do these three trucks have in common?
A) They all look great;
and B), they do so without the aid of an independent front suspension. There are plenty of
It's always a good idea to freshen up the core wearable components before making major mod
This Royal King Pin Kit from Stainless Steel Brakes Corporation (SSBC) is a great way to i
Another great way to improve handling on an otherwise stock suspension is to add a sway ba
We can't stress enough the importance of quality brakes on a classic truck that sees regul
Shown here is a five-lug Chevy conversion kit from ECI and a six-lug Chevy kit from CPP.
Care to add some high-tech performance and sparkle to your straight-axle brakes? SSBC offe
Don't forget the dual-chamber master cylinder and power booster when upgrading your brakes
Power steering is another upgrade that's getting easier and easier to make on many straigh
Here's a similar power steering kit from Golden State Parts, only this one is designed for
Leaf springs can be de-arched for a lower stance. You can also have a spring shop reverse
Mono-leaf springs are another option for getting a lower stance and better ride quality. T
Back in the '50s it was pretty easy to find an axle shop that would heat, bend, and stretc
A different approach to the dropped-axle concept is this new fabricated version. F-100 ver