What You Should Know When You Upgrade a 1970 Chevrolet Camaro Into A Borgenso Power Steering


The Saginaw recirculating ball steering box was used in just about every Chevrolet built. There was a couple of ratios used coming from a lazy 16: 1 within the trucks and big cars as much as an ultra-quick 12.7: 1 in Camaros. We now have been working on a ’70 Z28 Camaro, and at first we were thrilled with its quick ratio steering. The slightest input on the controls turned the automobile. It was much like getting a new toy. Eventually, the fun factor wore off and we were left with a car that had been twitchy as well as a bit stressful to drive on the road.

With just 2-3/4 turns lock to lock, it takes almost no steering wheel input to turn the car a lot. Slow-speed driving and pulling into a parking spot were awesome. After we got the car up on the road is when our issue with the fast ratio arose. Just looking over our shoulder to check the blind spot made us turn the wheel slightly, but that slight movement was enough to improve lanes. Again, it’s something we might tailor our driving style to compensate for, but because of modern technology, we don’t have to.

Borgeson, a firm that has been within the steering and U-joint business since 1914-that’s 100 years, folks-has a cure for our twitchy steering woes when it comes to a remanufactured 700-series variable ratio steering box. The 700 box is from a later application and offers better feel in comparison to the older boxes, thanks in part to better internal components. The variable ratio offers a quick final ratio, with only three turns lock to lock, but it’s not overly sensitive on center for stable highway driving. Basically, as soon as the wheel is around the center, it has a ratio of about 16: 1, which gives you a little more stability at slow speed. Now as soon as you start to turn the wheel, the ratio speeds up as you grow further in the center. And by the time you get to the end of the steering, you have a 13: 1 ratio.

Since we are speaking about a power steering box, it’s gonna want a pump plus some other accessories to support it. Borgeson had everything we needed, except the fluid. We picked up a new power steering pump, lines, plus a rag joint to complete the upgrade. At this time, we also decided to get new steering components like the centerlink, tie rods, and pitman arm from Performance Suspension technologies (PST), so there will be no slop in our new steering system.

One question you might have before we receive into the install is, why didn’t we convert to your rack-and-pinion setup? Well, we replaced all things in our steering system and even upgraded the box-and still came in at half the price tag on a typical rack conversion.

1. We had Jeff Grantmeyer from Borgeson tear open variable and non-variable boxes and explain the difference between your internals. First, let’s get into some common items. Here we have the steering gear case inside the center. Above that is the sector shaft, top cap, and lower sector bearing. To the left we certainly have the rack block/worm gear, and on the correct is the torsion bar valve assembly as well as the endcap.

2. Sector teeth on left are variable ratio. You will discover a wider spacing with a larger center tooth. This effectively changes the ultimate ratio of the gearbox as the steering gear moves away from the center tooth and on the shorter outer teeth. The worm gear rack piston assembly ratio is constant; the actual ratio change originates from the difference in sector tooth height.

Sector on the right is square ratio. It has the same constant ratio throughout the range of steering motion. The ratio through the worm gear/rack piston assembly is transferred squarely towards the pitman arm.

3. The rack block/worm gear assembly on the left is a square ratio. You will notice the tooth spacing, just like the square ratio sector shaft, is even and constant. The assembly on the right is the variable. Notice the uneven tooth spacing with the larger deeper cut for the corresponding sector tooth. Both of these assemblies have the same worm gear ratio. What is so that it is variable is, again, the cutting from the teeth around the sector and rack block.

4. Now let’s end up in the wrenchin’. We used a pickle fork to free the centerlink in the pitman arm.

5. After using a crescent wrench to take out the large nut on the pitman arm, we used the appropriate puller to slip the pitman arm off the end of the output shaft. Without it puller, this will be pretty dang difficult, so make sure you havebought and rented, or borrowed one before you start your swap.

6. Next will be the power steering pump. We loosened it to take out the belt and then took the entire pump with brackets off the front of the motor. We sat the assembly on the inner fender for now. We are going to do the rest of the teardown on the bench.

7. We removed the pinch bolt from the rag joint connection on the box. A little persuasion with a prybar freed the joint from your box.

8. The box will be the last component to come off. Since the pump and hoses are still hooked to the box, the help of an assistant is required to wrangle everything stuff out. We might suggest taking out the lines and taking out the package and pump in separate pieces if you are doing the job by yourself.

9. Now it’s time for some new stuff. Borgeson has these rag joints in stock, plus they are pretty much all set. All we needed to transfer over to the new unit was this bracket. Rag joints are designed to dampen vibrations and isolate the steering wheel. They are certainly not made to accommodate an angle. Look to a U-joint should you don’t use a straight connection. But in stock applications like ours, a rag will continue to work great.

10. We used the new hardware in the Borgeson kit to put in the new rag joint.

11. We made sure it had been in the center, before we installed the box. To put the box in its center position, we turned the input shaft all the way to the right. Once it hit the stop, we turned it the other way till it hit the other stop, counting the turns as we did. This box has a three-turn lock-to-lock count, so we turned the shaft 1-1/2 turns to put it in the center. We used the factory hardware to hang it from your frame. We left the hardware a bit loose for the time being. We will keep coming back and tighten it all the way up once all things are hooked up.

12. After some cleaning along with a fresh coat of paint, the pitman arm is installed. The output shaft has four master splines on it, therefore the pitman arm can go on in four locations, but since we centered the box, we knew pointing straight back was the correct position.

13. We found it necessary to rob the pulley and brackets off the original pump to transfer them to the new Borgeson unit. We used a positive change gun to take out the nut. Once we had everything swapped, we tried to install in on the motor. We discovered that the new pump housing created a clearance issue with the return hose.

14. Here is a side-by-side shot to indicate our issue. The return protrudes in the new housing square in the middle and this wound up hitting the block, preventing us from even getting each of the bolts in. Since we know our housing worked, we are going to swap them out.

15. First, thing we did was loosen the hardware in the rear of the pump. There are 2 items that must definitely be loosened: one bolt, one stud. We completely removed the hose fitting.

16. Under the fitting is a spring and a valve. These needs to be kept in this order to function properly, so keep that in mind when tearing yours down. The spring and valve are what determines pressure of the pump.

17. The pump comes with an O-ring seal that will make getting the pump from the housing a bit difficult. Ever since the O-ring seals on the housing, we don’t want to pry on the housing at all to separate the various components. We used the loosened hardware as being a push point that allowed us just to push the pump out.