Upgrade Your Mopar With High-Performance Power Steering

When our classic Mopars first hit dealer showrooms, factory tires consisted of skinny bias-ply rubber, and power steering was more of a luxury than a necessity. However, as these cars received wider tires via car owners in the quest for better handling, that standard-fare manual steering became cumbersome at best. Especially when it came time for low-speed maneuvers like what occurs in a parking area.

Mopar power steering

The install is accomplished with PN: 999063 power steering conversion. It is for cars with a 1 1/8-inch Pitman shaft and LA-series small-block engines. It includes the 14:1 quick-ratio steering box, pump, bracket, pulley, hoses, and steering-column coupler. The coupler is designed for use when upgrading cars already equipped with power steering.

Years ago, the only option available to upgrade to power steering was to find another car that had what you needed and glom the parts to complete the upgrade. The problem enthusiasts have now, is where to find OE parts to make the swap. Since original parts are getting harder to find, more expensive than ever, and are usually worn out, many enthusiasts are turning to kits from Borgeson Universal Company.

I first removed the roll pin in the steering-column coupler (left) by tapping it out and then disconnected the Pitman arm (middle) from the box. Remove the three bolts holding the box to the K-frame, and that's all it takes to get the old box out of the car. The steering box on top is the new Borgeson unit and the bottom one is the "old" aftermarket box.

Borgeson makes steering box upgrades for enthusiasts because they feel classic cars and trucks can benefit from the same advances in technology later model cars enjoy. Jeff Grantmeyer of Borgeson says, “the boxes used in this Mopar kit are all new. The problem with rebuilding a 40-year-old steering box is that you still have 40-year-old technology.”

The Recipient

Before I get into the actual swap, let’s talk about the recipient. The car is a ’75 Dart Sport that came from the factory with manual steering. At some point, the owner upgraded the factory box with another company’s aftermarket manual gearbox in hopes of improving the steering. While the stock Mopar box delivered a 24:1 ratio, the aftermarket, quick-ratio unit was 16:1. The quicker ratio was definitely a better alternative than the factory box in some regards. However, with modern tires, steering was nearly impossible when the vehicle was moving slowly.

To install the pump and bracket, you will need to remove the two lower timing cover bolts from the front of the engine. They do thread into a coolant passage, so you will need to drain the coolant before removing them. The pump and bracket are assembled when you get the kit, and it simply bolts into place.

The owner wanted to upgrade to power steering, and Borgeson’s modern, quick-ratio power steering box to fit ’62 through ’79 Mopar cars was a great idea. That’s right, there is no need to scour swap meets looking for used parts. The Borgeson power-steering box is a direct bolt-in and mounts to the stock K-frame. It even uses your stock Pitman arm.

While this upgrade is great for manual-equipped cars, those with factory power steering can even benefit from the swap. A stock Mopar power-steering gearbox delivers a 16:1 steering ratio while the Borgeson quick-ratio box offers a 14:1 ratio. The box is even slightly smaller than the OE power-steering box, and according to Borgeson, offers a 10-pound weight savings (23-pounds vs. 33-pounds).

mopar power steering

With the steering column removed and the new gearbox mounted, you need to measure so you know where to cut the column. After the universal joint was mounted to the steering box, I found I needed to make the shaft 9-inches long, extending from the firewall.

All Things Considered

The new box is actually designed for those wanting to upgrade their existing OE power-steering with the Borgeson unit. The parts with the kit make the power-to-power swap easy. I want to let you know upfront, there are two things you need to consider when contemplating the swap: one, the shaft in your steering column will need to be cut in order to use the Borgeson Mopar power steering box. To accomplish the swap after cutting the shaft, the factory column-to-steering-box coupler is replaced with Borgeson’s vibration-reducing U-joint coupler (PN: 036425).

But, we are upgrading a non-power-steering car to include power, so things have to be done differently (more on that later). Secondly, If your engine has a single-groove crankshaft pulley, you will need to acquire a double-groove crankshaft pulley. These came on cars that didn’t have air conditioning but did have power steering. I had one on the shelf, but if you need one, I found them at 440 Source.com.

mopar power steering

The line furthest to the right is where the end of the vibration-reducing joint would have been located. The line to the left is where the end of the shorter U-joint would be located. By tapping the shaft into the column approximately 5/8-inch, I was able to connect to the solid round portion of the shaft once it was cut and modified.

The Long And Short Of It

Mopar power-steering columns are shorter than those found in cars with no power steering. If I were to cut the longer, non-power-steering column shaft in the Dart Sport to use the vibration-reducing U-joint, I would ruin the column shaft. The reason is that the cut would be made in a hollow portion higher on the shaft. This is not a safe option as far as I am concerned. The column needs to be cut at the solid portion of the steering shaft where the OE steering coupler resides. “The column-shaft issue you ran into is not apparent on all models the kits fit,” said Jeff Grantmeyer. “This will only be a problem on a 1968 and later Darts with factory manual steering.”

mopar power steering

I cut just enough of the shaft to leave sufficient material for the universal joint to attach.

After some measuring, it was determined that using Borgeson U-joint (PN014925) was a suitable option. This “standard” U-joint is shorter and does not offer the benefit of vibration reduction. I could live with that. With the proper U-joint in hand, I was able to cut the shaft in the “solid” area to fit almost perfectly. Unfortunately, even with this shorter U-joint, the column shaft was still 5/8-inch too long.

The round shaft is ground to create the double-D for attaching the U-joint. While this does not need to be a precision fit, a snug fit is definitely preferred.

Luckily, the steering shaft in all steering columns built after 1967 are collapsible. This collapsible shaft is comprised of an inner shaft and an outer sleeve which are kept stationary with a strong plastic “binders.” In the event of a frontend collision, the plastic allows the inner shaft to be moved (slid) into the outer sleeve. When this happens, the energy received through impact is absorbed by this collapsing shaft.

Since the shaft is designed to collapse, I asked Jeff if tapping the shaft inward (to “shorten” it) would create an unsafe condition. Although Borgeson does not recommend shortening the shaft a large amount by hitting it with a hammer, he let me know he felt it was safe to tap the shaft inward the small amount I needed. With the column’s length situation handled, I then needed to address the column-shaft to U-joint connection.

The small, solid portion of the shaft where I needed the U-joint to connect, is 3/4-inch in diameter. Borgeson has two U-joints that can be used. One is PN: 012564, which has the correct splines on one end, and a 3/4-inch smooth bore on the other. This U-joint does have set screws to hold it in place, but it is recommended that it be welded to the smooth shaft. This is a safe and effective option, however, the U-joint I decided to use (PN: 014925), has what is called a Double-D connection style. A Double-D shaft is a round shaft with two opposing “flats.”

Mopar power steering

I attached the U-joint to the freshly ground shaft, following Borgeson’s instructions for securing the set screws.

To make the round steering shaft fit the Double-D U-joint, I took a hand grinder and made two flats on the existing round shaft. It didn’t take long to grind enough material from the shaft for the universal to slide snugly into place. Modifying the steering column was not very difficult, and it actually took more time to get the column out of the car than it did to make the modifications.

mopar power steering

If your engine uses a single-groove pulley, you will need to locate a double-groove pulley. I had one in the junk pile I call a storage area, but you can get one at 440 Source.com

Bringing It All Together

Since this is a non-power-steering car from the factory, I also needed to install a power steering pump. While the Borgeson box is able to be purchased by itself, two complete conversion kits are also available for Mopar A-bodies with small-block engines (PNs: 999063 and 999064). Which kit you need depends on the diameter of the Pitman arm shaft. Pre-1973 boxes utilize a pitman-arm shaft with a 1 1/8-inch diameter while the ’73 and later units use a 1 1/4-inch shaft. If you’re not working on an A-body, Borgeson has parts for almost any car.

The kit came with the gearbox, U-joint coupler, power steering pump, reservoir, bracket, and the hoses. When ordering the kit, make sure you tell them if you have a non-power-steering car and order the shorter U-joint that I mentioned.

I found a 37.5-inch V-belt fit nicely. I tried a 37-inch belt first, but couldn't get it over both pulleys. The last three numbers denote the belt's length.

I was pleasantly surprised the swap only took the better part of one day — not counting the downtime for ordering the new U-joint. Once everything was back together, it was time to see how much better the steering felt — if at all.

As I backed out of the garage and around the corner, I first noticed how easy it was to steer the car while hardly moving. That was a pleasant change. No more worrying about breaking off the steering shaft while trying to turn the wheel during a nearly stopped situation.

Mopar purists will notice the different column-to-gearbox coupler, But as far as I am concerned, the change is definitely for the better.

While maneuvering under normal driving conditions, the absence of the vibration reducer was barely noticeable. Sure, there was a little more road feel than there would have been if using it, but I still feel it is a non-issue. Overall, steering is now much-less labor-intensive, and the car has the firm-driving feel we hoped the Borgeson kit would deliver. Now it’s time to find some twisty roads and really give it a workout!

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About the author

Randy Bolig

Randy Bolig has been working on cars and has been involved in the hobby ever since he bought his first car when he was only 14 years old. His passion for performance got him noticed by many locals, and he began helping them modify their vehicles.
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