Quick-ratio Power Steering for Your Early Jeep WillysPosted in How To: Transmission Drivetrain on September 21, 2015
We've always hated juggling the wheel of a slow-ratio power steering system. Some common 4x4 steering boxes require up to four turns lock-to-lock. After spending only a short time behind the wheel of friend's fullsize prerunner with a 2:1 ratio steering quickener, we were sold. Our flatfender needed a quick-ratio steering system, especially given the incredibly short wheelbase. Quick steering isn't for everyone, though. Some people don't like very responsive steering and consider it too twitchy. However, if you are used to high-performance road cars, you should be able to easily adapt to a quicker steering ratio.
There is more than one way to achieve a faster steering ratio on your Jeep. Saginaw steering boxes are available in several different ratios, and they alter the number of turns required to spin the steering box from lock-to-lock. Most steering boxes provide around 3 1/4 turns lock-to-lock. Faster boxes can be found in some Camaros and provide as few as 2 1/2 turns lock-to-lock. The slowest of the bunch is probably the Jeep FSJ boxes at about 4 turns lock-to-lock. Unfortunately, not all of these steering boxes are interchangeable between different Jeeps. You still need to consider hose fittings, input spline count, and pitman arm clocking. If you are starting from scratch like us, it's a little easier to assemble a system that works. We made a call to Summit Racing to compile the steering components we needed for the quick-ratio system in our Jeep.
We started with a remanufactured three-bolt fast-ratio Saginaw steering box from a '79 Camaro (Summit Racing PN AAZ-27-6510). If mounted properly, the three mounting bolts are more than enough. This particular steering box mounts to the inside of the framerail and generally offers 2 1/2 to 3 turns lock-to-lock. We used a stock pitman arm from a '74-'91 FSJ.
Most '76 and newer GM Saginaw steering boxes have a 3/4-inch, 30-spline input. The '75 and older Saginaw steering boxes have a 13/16-inch, 36-spline input. Be sure you order the right parts to make the conversion before diving into your swap.
Our system includes Borgeson double-D steering shafts and steering joints from Summit Racing. To correctly mount the steering joints, we used the set screws to mark the shaft once the proper length is determined.
We used a 3/8-inch drill to make 1/8-inch-deep holes for the set screws to seat into. This will keep the assembly from coming apart in abusive conditions. Always use thread-locking compound on the steering hardware.
The Howe Stealth HD (Summit Racing PN HRE-522B2) is one of the strongest steering quickeners on the market. It features a 2:1 quickening ratio, which may be too twitchy for some drivers. Summit Racing also offers other quickeners with less aggressive ratios. Our quickener was coupled to the steering shafts with 36-spline/double-D Borgeson solid couplers, also from Summit Racing. The quickener needs to be mounted to a cage or other rigid structure without being bound up. Follow the included directions closely or your steering will not spin smoothly.
Underhood clearance of a flatfender Jeep is at a premium. We needed to add a third joint to our steering shaft system. The use of a third joint required a pillow block to keep the shaft from flopping around. This 3/4-inch rod end (Summit Racing PN BRG-700000) kept our shaft in line.
Summit Racing offers a weld-on Saginaw steering box mount (PN ADD-716838) for early Jeeps, but we built our own steering box mount using heavy-wall DOM boss tubing. It's welded directly to the frame with three passes on each side. Our fabricated mount allows for the installation of a heavy-duty four-bolt steering box if we ever find a need for it.
Summit Racing offers this trick firewall-mounted pillow block (PN BRG-700010), but we couldn't get it to work with our system. Plan out your steering and check for clearance by mocking it up with broomsticks or PVC tubing before ordering any parts.
Our three-joint steering shaft pokes around the power steering pump thanks to the support of the rod end pillow block. We built a small mount for it from 1/8-inch-thick strap steel and welded it to the frame.
On the business end of our steering shaft we installed a splined weld-on quick release steering wheel coupler (Summit Racing PN GRT-3024).
The steering quickener is mounted to a two-bolt tab on the rollcage. We used a weld-on steering column mount from AA Manufacturing (PN AA-066-A) and a leftover 3/4-inch rod end to support the steering shaft.
Being a little nostalgic, we capped the steering off with the 14-inch three-spoke rubbed-mahogany steering wheel rescued from our long-gone previous flatfender (Summit Racing PN GRT-704).