1965 Olds Cutlass Steering System Upgrade - Staying On Path - PHR Project Car
Project Olds Gets A Complete Steering System Rehab With A DSE Steering Box And A Fresh Set Of Links.
From the April, 2010 issue of Popular Hot Rodding
By Stephen Kim
Everyone appreciates a nice rack, but not all is lost for the venerable recirculating ball steering box found in most muscle cars. Generally speaking, modern rack-and-pinion steering systems boast lower mass, fewer moving parts, greater durability, and more precision compared to their worm gear-based forbears. Despite what the elitist mainstream car rags would have you believe, however, the average driver would be hard-pressed to discern much of a difference in steering feel and response between a healthy recirculating ball steering system and a rack-and-pinion unit. That might explain why recirculating ball steering boxes survived in several high-end German sports sedans well past the turn of the millennium. Furthermore, the rise of rack-and-pinion systems in the '80s had less to do with enhancing performance, and more to do with the improved packaging they offered in tight front-wheel-drive chassis of the era.
Nonetheless, there's a big difference between a modern recirculating ball setup, and one that's been rotting away for the last 40 years. Although our '65 Olds Cutlass project car has been fitted with a Detroit Speed and Engineering suspension, Baer brakes, and fat R-compound Nitto rubber, all that impressive hardware is useless if the car doesn't want to go where you point it. To ensure that Project Olds clips through the autocross pylons instead of plowing over them, we decided to install a new DSE 600 Series steering box. Unlike the factory GM 800 Series box and its lethargic 20:1 ratio, the DSE unit features a quick 12.7:1 ratio, low-friction gears, and rack-and-pinion valve technology for vastly improved steering response and feel. Plus, the DSE box is 6 pounds lighter to boot. Although it was included as part of the DSE front suspension kit that we installed in the February 2010 issue, the 600 Series unit can be purchased separately for $495.
DSE's 600 Series quick-ratio...
DSE's 600 Series quick-ratio steering box is available as part of the company's front suspension kits, or individually for $495 under PN 090204. When bundled together as part of a suspension package, the kit includes new inner and outer tie rods, a pitman arm, an idler arm, a rag joint, and tie-rod adjuster sleeves. The steering box is compatible with GM '67-92 F-bodies, '64-72 A-bodies, and '68-74 X-bodies.
Equally as important as upgrading the steering box itself is rehabilitating the rest of the steering system. A recirculating ball arrangement relies on a series of linkages and rods to convert output from the steering box into changes in steering angle. Any free-play or distortion in those links or rods leads to sloppy steering and compromised directional stability. Consequently, the beat-up factory pitman arm, idler arm, drag link, and inner and outer tie rods were all replaced with fresh hardware. Furthermore, we installed a fluid cooler to extend the longevity of the power steering pump. Brent Jarvis of Performance Restorations graciously volunteered his services once again for the install. The complete setup bolted right up in one afternoon, and at the end of the day, Project Olds finally had a proper guidance system that would enable it to fully wring every last micro-g out of its cutting-edge chassis.
Factory power steering pumps...
Factory power steering pumps are notorious for overheating under heavy road race or autocross usage, but ours was in great shape, so we decided to keep it for now. To prevent it from boiling its fluid, we installed an aluminum 15x3 1/2- by 2 1/2-inch cooler (PN 55-60350) right behind the grille. Its finned design features 475 square inches of surface area, and 16 ounces of capacity. The 1/4-inch NPT inlet and outlet fittings were swapped out for -6AN pieces from Russell.
The stock steering box is...
The stock steering box is attached to the driver-side framerail with three bolts, which will be reused later on. The old pitman arm doubles as a handle to make supporting the heavy box much easier as the bolts are removed. If reusing the pitman arm, it must be detached from the steering box output shaft using a puller tool, but since plans called for installing a new arm, we left the old one attached.
Jarvis says it's a very common...
Jarvis says it's a very common mistake to install a new steering box with its input shaft cockeyed. To make sure it's centered, he recommends mocking the pitman arm into place, and marking the box at the points where the output shaft turns farthest to the left, and farthest to the right. Positioning the output shaft directly between these two points will ensure that the input shaft is centered before it's attached to the steering shaft.
With the new rag joint slid...
With the new rag joint slid over the input shaft, the DSE steering box attaches into place using the factory bolts torqued to 70 lb-ft. The splines on the pitman arm and steering box output shaft can only go on in one direction. Jarvis then tightened it down to 120 lb-ft, and installed a new cotter pin. After straightening out the steering wheel, the rag joint was bolted to the steering shaft on one end, and the input shaft on the other.
A worn-out idler arm can change...
A worn-out idler arm can change the angle of the plane in which the drag link travels, significantly altering steering geometry. The new idler arm bolts to the passenger-side framerail using Grade 8 hardware. The joint comes pre-packed with grease, and has zerk fittings so it can be recharged at any time.
The DSE adjuster sleeves included...
The DSE adjuster sleeves included with our front suspension kit allow fine-tuning the length of the tie rods to minimize bumpsteer and simplify the alignment process. In order to get the tie-rod lengths in the ballpark before final alignment, Jarvis set them both to the same overall length as the stock units, which measured 18 inches. It's good practice to make sure that the same number of threads are engaged on each side of the sleeve.
With the pitman arm and idler...
With the pitman arm and idler arm in place, we installed a new stock replacement drag link from Moog (PN DS740). A-bodies came equipped with both 13/16- and 7/8-inch drag links from the factory, and Project Olds had the smaller of the two. While the bigger 7/8-inch unit can also be installed, the switch requires ordering up tie rods, an idler arm, and a pitman arm specific to the larger drag link. The tie rods were then bolted to the DSE steering knuckles, which feature two mounting points to help dial out bumpsteer. Ideally, the tie rods and lower control arm should be as close to parallel as possible, which minimizes the disparity in arcs in which both links travel. The lower of the two mounting points on the DSE knuckles proved to accomplish this most effectively.
The DSE steering box features...
The DSE steering box features an M18x1.5 port on the pressure side, and an M16x1.5 port on the return side. Since power steering pumps operate at close to 1,000 psi of pressure, Jarvis felt it was a good idea to install -6AN stainless steel braided lines using metric-to-AN adapter fittings on the pump. Under extreme conditions, cheap rubber lines can corrode and completely fail.
The slim Jegs power steering...
The slim Jegs power steering fluid cooler fits beautifully behind the driver side of the grille, a location which will provide a steady stream of cool air. It was mounted to the upper radiator support using the supplied brackets. Jarvis plumbed the cooler into the return line, right before the fluid enters the pump, in order to maximize its cooling efficiency.
Reusing the stock power steering...
Reusing the stock power steering pump required welding -6AN port adapter fittings to both the pump and reservoir. The final step in the steering makeover is filling the pump up with fluid, and purging air out of the system. This involves turning the steering wheel from lock to lock several times with the engine running. During this process, additional fluid should be added as necessary.
Not only does the stock steering...
Not only does the stock steering box require 5.5 turns from lock to lock, the giant-rimmed factory steering wheel attached to it turns what should be brisk direction changes into fervent saw-fests. To get the most out of the new quick-ratio 12.7:1 DSE box, we installed a new Grant three-spoke Collector's Edition steering wheel.