In Part I of this tech article, which ran in August 2006, we brought you information about our great conversion for your 1958-1964 passenger cars. As we stated,this conversion can be one on cars with small blocks or big blocks. Cars with air conditioning can be converted also. It uses GM's "605" steering box, which has "the power" right in the box. The 605 power steering boxes were used on mid-sized GM cars produced in the mid to late 1970's and throughoutmost of the 1980's. (Recall Step # 17, in Part I, for more information.)

As discussed, the basic conversion requires a bracket for mounting the 605 to the frame. Our bracket, cast out of a high strength alloy (Al-Mg 535), is one of the best you can purchase, because it mountsthe bracket to the 605 using the original threaded holes of the 605.

Our bracket kit (PIN 553005) allows you to bolt-on a late model power steering box and comes with the mounting hardware required to install the 605box. This conversion requires that the car have the standard steering linkage between the wheels. Specifically it must have a standard steering pitman arm, drag link and idler arm.

Parts List
1958-64 Small Block 605 Power Steering Conversion Kit
1960-64 348/409ci 605 Power Steering Conversion Kit
1958-64 396/427/454ci Big Block 605 Power Steering Conversion Kit
1955-72 Double Groove Crankshaft Pulley
1955-72 Small Block & 348/409ci Double Groove Water Pump Pulley
1955-72 Single Groove Harmonic Balancer Pulley
1955-68 Small Block Single Groove Short Water Pump Pulley
1955-72 Power Steering Pump Pulley
1960-72 Power Steering Pump & Bracket Stud
1958-1964 Chevy 605 Style Steering Box Mounting Bracket Kit upgarded steering box
1958-64 605 Or 500 Series Power Steering Box To Original Column Or ididit Conversion Shaft & U-Joint

Tools Needed:
Various 12-point Sockets
Ratchet (5/16" to 11/16")
Various 12-point Wrenches 5/16" to 11/16")
Various Line Wrenches
Various Taps or Thread Chasers (5/16"-24, 3/8"-16, 7/16"-14)
Pitman Arm Puller

Time Frame
4.5 Hours

Image #21-22-23: With A/C. The following is what you need if you have A/C: a water pump double pulley (GM tracks #1 and #2) which is our PIN 563652 and a harmonic balancer double pulley (GM tracks #1 and #2) which is our PIN 563650. You will also need another harmonic pulley (GM track #3) which is our PIN 564207 (Photos 21-23). The power steering pump uses GM's track #3 and the belt goes around the harmonic balancer and the power steering pump. The only pulley still available for the pump is a double pulley (GM's tracks #2 and #3) which is PIN 553071. (Photo 22)

Without NC. The following is what you need if you do not have A/C: a water pump single pulley (GM track #1) which is PIN 563943 and a harmonic balancer double pulley (GM tracks #1 & #2) which is P/N 563650. The first track belt goes around the water pump, crank and alternator or generator (Photos 21-23). The power steering pump uses GM's track #2 and the belt goes around the harmonic balancer and the power steering pump. The only pulley still available for the pump is a double pulley (GM's tracks #2 and #3) which is PIN 553071 (Photo# 22)

Image #24: Step 15. . Install the correct pulley or pulleys at the harmonic balancer. Secure with the three 3/8-24 x 1" bolts and lock washers. The crank pulley bolts should be tightened to 45 foot-pounds.

Image #25: Step 16. Install the pulley on the power steering pump. Make sure that the Woodruff key is positioned on the pump shaft before installing the pulley. Check the alignment of the pulleys with respect to each other. The tracks need to be lined up. Select the pump belt that you will use. The length of this belt is critical. The amount of adjustment is minimal. The belt has to be long enough to be installed, but not so long that it is impossible to tighten. (I used a flat-blade screwdriver to "pry" the belt into position.) This belt will be installed later.

Image #26-27-28: Step 17. There are two 605 boxes, one has flare-type hose fittings and one has O-ring fittings. The flare-type boxes were used in the early years and the O-ring style in the later years. The flare style will have the brass seats and the O-ring will not have the seats. The 605 boxes in our kits are the O-ring type (Photos #26 & 27). All of the 605 boxes will have "605" cast (5/16" high numbers) in the housing (Photo# 28). If you are looking for such a box at a junkyard, the "605" will be visible as you look over the fender down on the box.

Image #29-30-31-32: Step 18. Just before starting the installation of the 605, use a 7/16-14 tap to clean the threads of the three mounting holes in the 605 box (Photo 29). Use a medium strength Loctite product on the three black socket-head bolts, which will secure the box to the special Al-Mg 535 bracket (Photo 30). Position the bracket onto the 605 box and start each of the three socket-head bolts (Photos 31 & 32).

Image #33: Step 19. There are 3.5 turns from lock-to-lock on these boxes. While protecting the upper shaft with a rag, use a pair of vise grips to position the sector shaft at the midway point. To make sure that the 605 box is halfway, tum the upper shaft until the sector shaft is either at the end of the "right tum" or "left turn", then turn the shaft in the opposite direction 1 ¼ turns. The sector shaft has four flat areas on the splined end (see arrow in Photo 33). At the midway point, one of those flat areas will be pointing toward the front of the car when the box is on the frame.

Image #34: Step 20. Now the box bracket assembly can he bolted to the frame. The three 3/8-16 x 3 ¼" bolts, provided in the bracket kit, will be installed in the original holes in the frame.

Image #35: Each of the bolts should have a flat washer and lock washer in place as you begin to secure the box bracket. These bolts will be screwed into the Al-Mg bracket. As you position the box/bracket assembly, place the pitman arm onto the sector shaft. (At this time the pitman arm does not have to he completely installed onto the sector shaft.) Leave each of the bolts loose until all three are started into the bracket. You may have to wiggle the box/bracket assembly a little to get all three bolts started. Tighten these mounting bolts to 30 foot-pounds of torque.

Image #36: Step 26. Line up the matching flat areas of the sector shaft and pitman arm. Install and tighten the large lock washer and nut, which secures the pitman arm.

Image #37-38: Step 22. At this time, the belts will he installed. The photo showing the tightening of the power steering belt does not show the alternator belt or the NC belt, but these do need to be "installed" before the power steering belt is installed. Hang the belts over the harmonic balancer and the water pump: these will he installed later. The reason for doing it this way is that tightening the power steering belt is easier without the fan and water pump pulley in place. Notice in Photo 37 the bolt, flat washer and lock washer, which will tighten the power steering belt. Position the power steering belt. Use the shortest belt that you can pry over the pulley. There is very little space for tightening the belt. Be careful where you pry to tighten the belt. Use a large flat-blade screwdriver as shown in Photo 38 to tighten the power steering belt. Use a 9/16" wrench or socket to tighten the upper bolt on the rear of the power steering pump. At this time, tighten the lower rear nut and the lower front bolt on the power steering pump. Make sure that the pulley does not come in contact with the 605 box and that all of the pulleys line up.

Step 23. Install the fan and the correct water pump pulley with four 5/16-24 x 3/4" bolts and lock washers. The water pump pulley bolts should he tightened to 20 foot-pounds of torque. Make sure to check the alignment of the pulleys with respect to each other. The tracks need to be lined up.

Image #39: Step 24. The intermediate steering shaft must be shortened. You can measure for your own application. I have found that if the shaft is shortened to 19", it works very well. The length is an overall length, end-to-end.

Image #40: (I have heard from a few installers that some cars require shafts that were as short as 18.5" and as long as 19.5".) If you choose to use a shortened original intermediate shaft, have the shaft shortened by a good machine shop. This is not something you just cut and weld: remember this is a steering shaft. A much better idea is to use the new shaft provided in our kits or order PIN 553030.

Image #41: Step 25. Install the new Borgeson coupler onto the 605 box, but do not tighten the set screw at this time. Position the new shaft along the side of the lower (Borgeson) and upper (original) couplers. Determine how much of the splined ends need to be removed for a proper, no-bind fit. If the splined end protrudes into the center portion of the coupler it will inhibit the swivel action of the coupler. For this installa tion it was necessary to cut about 1" from each end. This is best accomplished with a power cutoff wheel. File or grind the raw cuts for a smoother installation.

Step 26. Install the splined shaft into the upper (original) coupler and slide it up far enough so that the shaft can slip down into the lower (Borgeson) coupler on the box (Refer to Step 3, in Part I, August 2006). Position the shaft and the couplers so that neither is hitting the steering box nor binding. Mark the upper splined area on the shaft for the upper bolt groove (Photo 41a). Remove the shaft and grind a notch at the marked area on the shaft. This will allow the upper clamp bolt to be installed. Install the shaft again along with the original upper coupler assembly with the clamp. Tighten the set screws and locking nuts on the Borgeson coupler (Photo 41b). Tighten the upper coupler bolt and nut. (Photo 41c)

Image #42-43: Step 27. Make sure one last time that you have the correct hoses for the 605 box (Refer to Step 17).Connect the return hose to the 605 box (Photo 42). The correct hole will be the position closest to the frame. Do not tighten at this time. Connect the pressure line to the 605 box. The correct hole will be the position closest to the engine (Photo 43). Tighten the pressure line so that it is not in contact with anything, specifi­ cally the engine or A-arm. Tighten the return line so that it lines up with the pressure line. Make sure that this hose does not come in contact with anything, specifically the engine, A-arm or steering shaft. Tighten both of the hoses at the back of the pump.

Step 28. If applicable, position the A/C belt (GM track #2) and tighten. Install the alternator or generator. Position the alternator or generator belt (GM track #1) and tighten. Check all clearances and alignment of the tracks. Fill the pump with power steering pump fluid. Cycle the steering wheel from side-to-side two to four times to pre-bleed the system. Refill the pump and repeat the cycling process. Check the fluid one more time.

Step 29. I suggest that you check all of the bolts, nuts and fittings one last time. Make sure that they are tight and that all clearances are maintained. Have someone cycle the steering wheel from side-to-side while you watch the 605 box. Make sure that the box and bracket are tight and that there is no play or flexing going on as the box is cycled. Carefully test your new steering system. I also suggest that the front end be aligned. The alignment specs are: Caster is 2.5-3.5 degrees, Camber is 0.5 degrees positive and Toe-in is 0.1875-0.500". You sho uld now have a great late-model power steering system in your Late Great!