Faithful followers of Mustang and Fords know that a rack-and-pinion conversion is one of the best things they can do to modernize their classic Ford. But maybe you've found sometimes all is not as it seems-word of mouth complaints, swap-meet conversations, and countless Internet chat-room rants surrounding the conversion have made you squeamish about taking the leap to better steering and handling. Our goal is to show you how and why things work, along with the right way to get your car handling properly.
There are typically four phobias about a rack-and-pinion conversion:
- Will the rack fit?
- Will my headers fit the rack?
- Power-steering pump issues.
- Bumpsteer? More like bum steer.
We'll discuss each of these as we go through our conversion. Our guinea pig is a '70 Mustang convertible that's already had a complete frontend rebuild. The conversion rack system has been provided by Randall's Rack. After installing several different rack systems on different cars, we really like the way Randall's has thought through the complete system, and the company is constantly improving its product. In fact, while writing this article, we got several new toys from Randall's, demonstrating its continuous improvement mindset. Those are the kind of guys we like working with.
Our rack-and-pinion conversion was performed at DVS Restorations in Crawfordsville, Indiana.
Phobia #1: Will the rack fit?
There are several reasons why people run into fitment issues:
Forty years of twists, rust, wrecks, and Dukes of Hazzard-style driving are not kind to these cars. Not only that, but we've seen cars with as much as 11/44 inch of fitment slop from the factory. We've had to beat rack-mounting brackets into cars in the past-not because the bracket was bad, but because the cars were poorly made.
Aftermarket parts are another problem. Big, deep, oil pans are usually the culprit, but other items, such as headers (an entirely separate phobia), braking upgrades, and so on can all cause fitment issues. As enthusiasts, we have to give the rack guys some latitude and understand that it is impossible to design for every aftermarket parts combination, but they should get a decent majority of them.
Poor design. OK, time to put the manufacturers on the line here. We've had stuff that had us shaking our heads trying to figure out what the engineer was thinking. If you've ever installed any aftermarket parts on your car, you have thought this at one time or another.
The Randall's Rack system addresses all the above issues. It uses an adjust-able mounting bracket to adapt to 40 years of frame twisting. The hybrid style of tie-rod system reduces the footprint for parts clearance, and all but the biggest aftermarket parts typically clear. Existing bolt holes are used for the steering gear, idler arm, and crossmember, so there are no conflicts connecting to the suspension or adding additional holes. The only modification to our car was to grind about a 1/4-inch notch on the driver-side engine mount support, which took about 30 seconds. No notching frames, no welding, and it's fully adjustable.
The Randall's Rack system...
The Randall's Rack system is a true bolt-in system that uses existing bolt holes in the frame to mount and has adjustments for minor frame irregularities. Placement of the steering output shaft is excellent, minimizing interference with the exhaust system and reducing the steering shaft angles.
Randall's offers a modern...
Randall's offers a modern pump with either a V-belt or a serpentine-belt pulley. Brackets are available for small- and big-block applications, and the pump has a built-in reservoir, so no additional holes to mount a tank are needed.
Although you can use a traditional...
Although you can use a traditional Ford power-steering pump as shown on the left, it isn't really designed for use with a modern steering system. To get maximum performance out of your new steering system, use a modern-style pump.
Randall's system uses a modern...
Randall's system uses a modern inner tie rod and your existing traditional tie-rod end to hook to the original spindles.
Phobia #2: Will my headers fit the rack?
Selecting the right headers seems to be the really big issue with rack-and-pinion conversions. The reason is that the gear in the rack is towards the middle of the car rather than bolted to the frame. This means you have a driveshaft cutting across real estate that used to be taken up by the headers.
Headers that were designed for the original cars are designed to clear the original steering gear mounted to the frame. Late-model headers won't work because they hit the shock towers and dump in silly places.
If you want headers that fit your rack system, look no farther than JBA's mid-length headers. Having experienced header issues with past rack installs, we were pleased to see how easy it was to install the JBA units and have no clearance issues whatsoever with our small-block installation.
For our application, the midrange header (PN 1650, $500-$650, depending upon material) runs towards the back of the block before angling down, which helps it clear the input for the new rack. Traditional headers start angling down almost immediately, causing a conflict with the steering shaft that's angling towards the steering column. The fact that JBA offers ceramic coating and stainless versions of the mid-length design makes for an even easier decision when selecting headers.
Owners of manual-transmission cars may need to look at clearance issues with the linkage to the clutch, while those with big-block cars already know how much gf a pain headers can be even without changing the steering (you've probably already had to modify the headers to fit, haven't you?). Our advice is to move away from 40-year-old header designs and look for a new one that runs towards the rear of the engine compartment before turning down. JBA can help you select the right header for your project.
Phobia #3: Power-steering pump issues
Most modern rack systems that are used in these conversions are designed for front-wheel-drive cars. Because of this, the pressure that the system works at and the weight of the chassis-and in some cases, the weight load over the front wheels-can have a dramatic effect on the performance of a power steering system. Although it might seem tempting to run out and start making your own rack systems, there is a considerable amount of engineering involved in making these systems work properly for a big-motor/rear-wheel-drive car.
If you're thinking about using your original power-steering pump to save a buck, we'd like you to reconsider. The original Ford pumps are not designed for the correct pressure range on the new rack systems. Although Randall's and other manufacturers will allow you to use the original pump, they don't recommend it because the performance of the rack is reduced due to the mismatch. It's better to use the manufacturer-recommended pump to get the maximum performance from your new steering system.
Randall's offers a modern pump that doesn't require an external reservoir for operation, so it's less intrusive to your engine bay. The company can provide the new pump with a traditional V-belt pulley or a new serpentine pulley for 5.0 conversions. It also offers a complete line of brackets to fit the pump to the old or new beltdrive systems.
Depending on your application,...
Depending on your application, Randall's provides the correct conversion sleeve to suit. The angled sleeves are used on later suspensions for additional clearance; the straight version fits earlier models.
The old manual-steering system...
The old manual-steering system from our '70 Mustang convertible was removed, and we measured the length of the tie-rod system. We'll use this information for a base setting on the new steering system.
To get the correct length...
To get the correct length on the new system, the inner tie rod should be trimmed about 111/42 inches before assembly.
Mark the end of the tie rod...
Mark the end of the tie rod about 1 1/8 inch from the end.
The tie rods are soft enough...
The tie rods are soft enough to cut with a hacksaw, if needed. Clean the ends, and you're ready to go.
Phobia #4 : Bumpsteer
One thing you have to remember about aftermarket parts-just because it fits doesn't mean it's good for your car. We have experienced bumpsteer nightmares with past conversions, so we decided we would not just print a lot of pretties about Randall's rack. We wanted proof that the rack system was a measurable improvement over the stock steering. So we got out our bumpsteer gauge and put Randall's to the test.
Most of the rack systems on the market use a center steer rack with a bar to mount the original-style tie-rod setup to the rack, which keeps everything in the original position (a good thing). This keeps the system from making the bumpsteer issues worse, and allows you to use aftermarket bumpsteer correction parts with your rack setup. Some other conversions are an end-steer design that allows for modern-style tie rods with better range of motion and a smaller footprint.
Randall's setup takes the rack system one step further. It uses a center steer design that incorporates a modern inner tie rod that better places the tie-rod pivot point for improved bumpsteer. We also think the Randall's setup has more range of motion over the stock-style tie-rod system.
When it came time for Randall's Rack to put up or shut up, we were pleasantly surprised with the test results for bumpsteer. We measured the Mustang with both the stock steering and the Randall's steering and found the bumpsteer was reduced to the point that no additional bumpsteer correction was necessary. It's actually below what most racers feel is OK.
Of course, with your suspension setup and parts, and driving habits, you'll want to check bumpsteer on your car, but for this car with a stock rebuild and slight ride height reduction, the numbers came out fantastic. Take a look at what we found.
As you can see on our test vehicle, the Randall's Rack significantly reduced the amount of bumpsteer. Still not good enough for you? For its more performance-oriented clients, Randall's offers an exclusive, fully adjustable center link that allows you to adjust the length of the tie rods and all but eliminate bumpsteer.
We're now at the point where we tell you how wonderful your car will be if you just go buy this stuff. Hopefully, we've gone beyond that and have succeeded in proving to you that with a little information and some data to back us up, your rack-and-pinion conversion can be less stressful and actually improve the feel and handling of your own vehicle.
The center of the rack system...
The center of the rack system has been marked from the factory. Take the measurement number you got from the old system, divide by half, and that tells you how long to make each new tie-rod assembly.
Here's the assembled tie-rod...
Here's the assembled tie-rod system. The angled tie-rod adapter adds additional clearance for the '67-'70 systems.
The white mark on the driver-side...
The white mark on the driver-side suspension/ motor mount support needed to be ground away for clearance on one of the power steering lines-that was all the modification needed to the chassis. By the time you read this, the lines will have been reengineered, so you won't need to do this.
Mounting to the driver side...
Mounting to the driver side shows the adjustability of the system and the non-intrusion with other components of the chassis. The rack mounts to the original steering-gear holes, and for additional strength mounts to the old crossmember holes.
The passenger side mounts...
The passenger side mounts horizontally to the old idler arm mounting points and vertically through the old crossmember point. No need to mess with the front suspension or its mounting point.
Header clearance has long...
Header clearance has long been a problem with rack upgrades because the steering shaft wants to cut right across where the old-style header use to run. JBA has taken care of this problem with its new mid-length header that runs back before it turns down. It makes most clearance problems all but fade away.
Here is a side-by-side comparison...
Here is a side-by-side comparison between the new JBA header and an old-school header (actually for a 351W). The older design starts moving downhill almost immediately, taking advantage of real estate not being used. The new design works its way back before slanting down towards the transmission tunnel.
Here you can see why so many...
Here you can see why so many people run into clearance problems with the old-style headers. The front two pipes are running right across where the steering shaft wants to go. It wasn't a problem with the old-style steering gear that bolted to the framerail.
This shows how the up-and-over...
This shows how the up-and-over design of the JBA header helps clear the steering-shaft assembly. We had absolutely no problems at all with our header install.
Since our Mustang is a '70...
Since our Mustang is a '70 model, we have the ignition key in the column that locks the transmission and steering wheel when the key is removed. To modify the column, it's easier to pull it out and make the changes on a bench.
The extra little lever on...
The extra little lever on the end of the shaft is our biggest concern. This round tube attaches to the transmission and prevents the tranny from shifting without the key in the lock. When we are done, the steering wheel will still lock, but this lever will be gone.
The lower end of the steering...
The lower end of the steering shaft slips into the upper shaft to provide safety in a wreck. The column slides together preventing (hopefully) the shaft from piercing the driver. The new shaft retains this collapsible-column safety feature.
Here's the new column shaft...
Here's the new column shaft assembly with the new bearing and collapsible shaft in place.
This end of the lever assembly...
This end of the lever assembly needs to be trimmed off and retained so the upper column collar can still be used.
Although you can weld the...
Although you can weld the bearing to the end of the shaft, we decided to drill holes and use blue Loc-Tite to secure the screws in place. If you ever have to get into the column again, this is the way to go.
The column is ready for reinstallation....
The column is ready for reinstallation. It simply bolts back in using the original firewall mount.
Owners of '65s-'66s will get...
Owners of '65s-'66s will get a new steering-column-to-firewall mounting bracket, which works with the stock steering shaft or even some aftermarket units.
No need to cut and trim solid...
No need to cut and trim solid rods to make your steering linkage. The Randall's system comes with a premade linkage that also has the same safety design as your steering column. Not only does it adjust to your vehicle, but it is also collapsible.
This view of the installed...
This view of the installed rack shows two things. First, you can see the generous ground clearance the Randall's system provides. Second, note the proper length of the tie rods doesn't bind the suspension system in any way. In fact, we feel the system has less bind with the Randall's system than the original tie-rod system.
For those hard-core racers...
For those hard-core racers who need that extra advantage, Randall's has an adjustable center link that can be used for reducing or eliminating the remaining bumpsteer from the system.
Before we let Randall's off...
Before we let Randall's off the hook, we decided to put the new steering system through a bumpsteer check. We started by leveling the car and setting the toe in, caster, and camber to the specifications provided by the company.
Next, we got out our bumpsteer...
Next, we got out our bumpsteer gauge and measured the new system. According to our findings, it reduces bumpsteer enough for all but the most hard-core drivers.
Here's an overall view of...
Here's an overall view of the new system installed-you can see how much room there is. The Randall's rack-and-pinion conversion, combined with the JBA headers, is by far the cleanest install we've done to date.