Power Steering for Tri-Five Chevys
Ryan Manson – Photography by the Author
When it comes to upgrading and modernizing a classic Chevy, one of the most popular modifications would have to be the addition of a power steering system. An option that’s as old as the automobile, traditional power steering assist didn’t really become a standard option until the early ’60s as technology and vehicle size collided. Premium lines like Lincoln, Cadillac, and Chrysler had offered power steering systems for decades, before the Big Three started offering the option as standard in the lesser, more affordable lines. By the ’70s, steering wheel sizes had decreased and power steering had become almost standard fare.
Today, adding a power steering system to most classic Chevys is as simple as swapping out that manual box for a power unit and adding a power steering pump and lines. With the proliferation of complete front assembly drives that contain all the mod cons (A/C, alternator, and power steering) all driven by a single serpentine belt it’s even easier to make that upgrade.
When Bruce Valley’s ’57 Chevy arrived at the Clampdown Competition headquarters, it had already been upgraded with a “poor man’s power steering” kit, which had helped improve the function of the manual steering box, but the big wagon was still a bit of a bear to parallel park or maneuver in tight spaces.
Creature comforts aside, the assistance of a power steering unit, be it electric or hydraulic, enables an increase in steering ratio, which results in a sportier, more-aggressive feel. This increased ratio means the steering box will require fewer turns of the steering wheel, lock-to-lock. In a manual box situation, this quicker ratio requires an increase of steering effort at low speeds, making it less desirable. In this situation, a slow ratio and a larger steering wheel made for a happier driver. The addition of power assist, however, overcomes the added steering effort, resulting in a “best of both worlds” situation.
We began the transformation by removing the steering linkage from one tie rod to the other, along with the pitman arm and idler arm assembly. We’ll be retaining the centerlink and pitman arm while the rest of the components will be replaced.
Bruce Valley’s ’57 Chevy Handyman wagon came with a manual steering box from the factory that served him well for many years. More recently however, it occurred to Valley that he desired a few more creature comforts than his four-speed, manual steering car could provide. It wasn’t a new car that he wanted, just the comforts of a modern vehicle in the classic package that he so loved. Thankfully, the classic Chevy aftermarket industry can deliver on just about anything a modern driver could imagine.
The components for Borgeson’s integral power steering conversion vary depending upon the existing components to be used. They can supply everything for a turnkey solution, including a power steering pump, lines, and brackets, and even a tilt steering column, if so desired. For Bruce’s application, we decided to stick with the stock steering column, which we’ll be modifying using the supplied Borgeson steering column shaft (PN 990008). Power steering pump responsibilities will be handled by the existing Concept One accessory drive system we previously installed on the LS3 engine that will be dropped between the Tri-Five’s framerails shortly. That said, we still needed Borgeson to supply a rag joint (PN 055034), fittings (PN 925128), and a steering column floor support (PN 909011) to complete the kit.
Another ’57 Chevy Upgrade: Brake and Suspension Upgrades Make a Handier Handyman
Since the addition of a power steering system was on the to-do list from day one, when we starting prepping Valley’s LS3 Connect & Cruise engine here at the Clampdown Competition shop, we installed a pulley system from Concept One that naturally included a power steering pump. With half the system in place, all that was left was to replace the manual steering box with a power unit from Borgeson, along with the proper replacement components.
Borgeson’s Tri-Five power steering boxes (PN 800105) are remanufactured using a Delphi 670 series box as a foundation, assembled and tested in the USA from components sourced throughout the world. Similar to the original Saginaw factory steering boxes, the new Borgeson power unit features a similar recirculating ball-style design, with the worm and ball nut assembly contained within a piston shape. This piston assembly is driven by hydraulic force from either end to assist in the steering effort. With a closer ratio than stock (12.7:1 as compared to 22:1), less turns lock-to-lock are necessary, resulting in a more responsive steering feel, making that classic Chevy perform more like a modern car. Here, the new box has been mounted in the original location using the original hardware.
After cleaning up the original steering centerlink and pitman arm, we attached new inner (PN ES577) and outer (PN ES234L) tie rod ends as well as aluminum tie rod sleeves (PN ES577SP-AB) courtesy of Classic Performance Products (CPP), before attaching the assembly to the steering box.
Over on the passenger side, we opted to complement the actual power steering system with another “poor man’s power steering kit,” also known as an idler arm bearing conversion kit (PN 5557IBC) from CPP. These feature a pair of roller bearings at either end of the idler arm instead of the original bushing design, resulting in an even further reduced steering effort. CPP offers the kit preassembled on a new idler arm and bracket (which is what we opted for) or as individual parts.
Back when we ordered the pulley system from Concept One for the LS3 engine, we also added a power steering hose kit (PN HK022) as we liked the ease of installation that the AN fittings would provide and the clean looks of the AQP fabric-covered hose.
The Borgeson steering box is designed to use O-ring fittings, so our hose kit reflects that and comes with the necessary hardware. Here, the fittings have been installed prior to fabrication of the power steering hoses. Note that the rag joint has also been installed in anticipation of the steering column installation.
To assemble the power steering hose fittings, first, the hose is twisted into the socket until it bottoms out.
Looking into the fitting, we can verify that the hose is where it needs to be.
The nipple assembly can push the hose out of the socket during assembly, so it’s important to retain a point of reference to ensure the socket/hose relationship remains. Here, a piece of masking tape acts as a reference line to determine any hose/socket movement and a touch of antiseize lubricant has been applied to the threads of the fitting.
With the nipple assembly fully threaded into the socket, give or take 1/16 inch, the masking tape reference tells us the hose stayed in place inside the socket and this assembly is good to go.
Next, it’s time to measure and cut the other end of the hose. A silver Sharpie marker is used in addition to a fully assembled socket assembly, installed on the steering box for reference.
The end of the hose is wrapped fairly tightly, with a few layers of electrical tape to prevent the inner layers of the hose from fraying during the cutting procedure. A 6-inch-diameter chop saw makes a quick, square cut through the hose.
The tape was removed and the hose cleaned before another hose end was assembled. Here, the hose has been installed between the low-pressure fitting on the box and the power steering pump reservoir. Note the slight bend in the hose to prevent any unnecessary tension.
The second high-pressure line is assembled in a similar fashion. Note that both hoses have been routed to ensure proper clearance between any moving suspension components.
Cutting the stock steering column is necessary if plans call for using said item. We trimmed the column just proud of the firewall to ensure there was plenty of room for engagement between the new steering column shaft, rag joint, and steering box. Here, the column has been temporarily bolted in place at the upper column support to check the length.
A new steering column weatherstrip pad (PN DCK-233) and floor seal (PN DCK-599) from Summit Racing will be used inside the car to keep out unwanted heat and vapors …
… while the aforementioned steering column floor support from Borgeson will serve to keep the bottom of the column secure.
Over on the workbench, the new shaft is installed inside the trimmed steering column, as are the new floor seals and lower column floor mount.
We decided to reuse the lower steering column bushing as it will serve to hold the stock lower seal.
Inside the wagon, the column is slowly lowered through the firewall while another set of hands in the engine compartment helps guide the assembly into the rag joint. Once fully seated, the upper column mounts are secured followed by the column floor mount. Note that the lower column floor mount utilizes the stock lower mounting fasteners in the firewall. Two setscrews secure the column to the floor mount once in place.
Next, the steering column weatherstrip pad is lowered into place …
… followed by the seal, which will be affixed in place using a set of firewall pad fasteners (PN dck-611) after the firewall insulation and carpet is installed.
With the column installed, the rag joint setscrews receive a dab of thread locker before being fastened in place.
A double hose clamp was added for neater routing of the power steering hoses, concluding our installation. As we get closer to initial engine fire-up, power steering fluid will be added and the system bled.
Saginaw Manual Steering Gear Manufacturing
We were able to catch some of the core components of a Borgeson Saginaw-style manual steering box being manufactured at their South Carolina facility recently, and while technical differences exist between a power unit and a manual box, their core components are very similar and manufactured as such.
Sector shafts begin as raw forgings.
The first operation is a rough turn of the upper OD and a machined “T” slot for the adjuster in a Haas VF-5 CNC milling machined.
The sector shaft is then turned to its final dimension and threaded in a Mazak CNC lathe. A purpose-built Gleason gear shaper, an original piece of equipment from the Saginaw plant, is then used to form the gear teeth.
After the teeth are shaped and the splines have been hobbed, the pitman shafts are sent out to heat treat. Upon return, they are finish-ground and then ready for assembly.
Worm gears start out as special-order bar stock that are cut to length and then rough-shaped and splined in a CNC lathe.
Another purpose-built Saginaw item, an old Barber-Colman gear hob machine is used to hob the correct ratio screw thread onto the worm gear. After this operation, each worm gear is sent out for heat treatment.
Back in the Borgeson factory, the worm gears are hard-turned in a CNC lathe and the thread is finish-ground.
Final worm gears, ready for assembly.
Like the other components, ball nuts start out their life as special purchase bar stock before being cut to length before a rough-bored hole is machined through in preparation for the internal thread to be machined.
After this operation, the blanks are sent out for copper plating. This plating acts as a heat treat stop off where only certain areas of the piece need to be heat treated, which is the next step in the process.
After heat-treating, an ID grinder is used to grind the internal thread of each ball nut.
A batch of ball nuts are ready for assembly.
Preload Adjuster and Top Cover
Both the preload adjusters and top covers are purchased as raw castings (left) and machined in-house to final spec (right).
Steering Box Housing
Steering box housings arrive as raw castings and are machined in-house on specially built fixtures that are finished in only two operations on CNC machines.
The internal components and housing for a Borgeson Saginaw manual steering box awaits final assembly …
… while a batch of finished products await final inspection.
Borgeson Universal Company
Classic Performance Products (CPP)
Concept One Pulley Systems