OBS Chevy Rack and Pinion Conversion | Flaming River

By Rob Fortier – Images by the Author

You would think, for the most part, that the factory-equipped power steering on your average 1988-98 OBS 1/2-ton would be sufficient for modern, everyday driving. We sure thought so. Then, suddenly, after the success of their bolt-in 1967-72 C10 rack-and-pinion conversion (followed by the 1973-87 version), Flaming River introduces their all-new rack conversion for the OBS (PN FR371KTPWNC) … so we began to wonder: is there room for improvement?

Unboxed Flaming River rack and pinion conversion kit laid out on a table, showing the mounting cradle, steering shaft, hardware, and installation instructions for an OBS Chevy truck.
The kit is designed to work with OE suspension (stock or up to a 6-inch drop), and, as you’ll see, with aftermarket suspension components, too! Also, the kit uses the factory power steering pump, further simplifying this bolt-in install!

Having installed both aforementioned conversion kits on the C10 and Squarebody, we were confident Flaming River knew what they were doing, so we searched for a conversion candidate —and what we came up with was more than we bargained for, in a good way.

Hoping for a superclean yet mostly stock ’88-98 shortbed, we ended up getting Ruben Pina’s insanely clean (more like stunning) ’95 Chevy—recently painted, upholstered, and full Stone Custom Fab suspension with 22-inch Hot Rods by Boyd wheels and Wilwood six-piston brakes, respectively. In other words, seemingly the perfect candidate for a rack-and-pinion upgrade. But even Pina himself was skeptical at first; he wasn’t sure why anyone would want or need to perform such an upgrade, but was more than happy to allow us and Flaming River to show him why!

Unlike the previous two cradle swaps we performed, this one for the OBS does not require an additional power steering upgrade in order to perform at an optimal level—it works with the OE C1500 pump, making the installation that much easier. Again, even with Pina’s upgraded Stone Custom Fab control arms, which included aftermarket tie-rod assemblies as well as a torsion-style sway bar, the Flaming River cradle was an easy, direct bolt-in requiring no modifications. It’s a good idea to ensure your factory column is in good, usable condition (not requiring a rebuild; Flaming River does offer aftermarket replacements if so) before performing the job, as well and making sure your factory front suspension is as well! The basic rack install shouldn’t take more than day’s work, providing your truck meets all the above requirements!

Mechanic bolting the Flaming River rack-and-pinion steering cradle to the front frame of an OBS Chevy pickup on a two-post lift.
Here’s the Flaming River steering system cradle, with rack, mounted to the frame. The driver’s side steering linkage is being connected.

After we’d spent the better part of a day with Pina’s Chevy, we sent him off for a quick alignment before giving his period-correct OBS a real road test. But when he got back to us after that following weekend, we weren’t prepared for what he had to report back: “…when I’m doing a hard turn or a U-turn, I don’t feel the ‘clicking over’ like it used to, almost as if the old parts had play in them. Also, when you’re driving and there are grooves in the road, the truck doesn’t track anymore—it just stays straight. Like I said, I didn’t even know I needed this or that this [kit] would fix all of those drivability issues!”

That’s not a magazine editor hyping up someone’s part(s); that’s a true testimonial straight from the truck owner himself! Doesn’t get much better than that, now does it?

Check out this story in our digital edition here.

Front three-quarter view of a lowered teal OBS Chevy Silverado pickup parked outside a shop after a Flaming River rack and pinion steering install.
If you read the story, you already know what Pina reported back after having his Chevy professionally aligned and putting some serious miles on the odometer—proving that to date, this is one of our most successful rack-and-pinion conversions!

 

Angled view of the Flaming River rack-and-pinion assembly, mounting bracket, universal joint steering shaft, braided hoses, and hardware on a workbench.
Flaming River’s all-new rack-and-pinion conversion kit for the 1988-98 Chevrolet/GMC C1500 (PN FR371KTPWNC); the steering upgrade you never knew you needed for your OBS!

 

Unboxed Flaming River rack and pinion conversion kit laid out on a table, showing the mounting cradle, steering shaft, hardware, and installation instructions for an OBS Chevy truck.
The kit is designed to work with OE suspension (stock or up to 6-inch drop), and as you’re about to see, with aftermarket suspension components, too! Also, the kit uses the factory power steering pump, further simplifying this bolt-in install!

 

Underside view of a teal OBS Chevy truck on a vehicle lift showing the stock steering drag link, tie rods, and front crossmember before removal.
Ruben Pina was gracious enough to let us “borrow” his beautifully redone ’95 Chevy for the install, which we’d assumed still had OE control arms, when in actuality it had Stone Custom Fab’s full coilover conversion kit with Wilwood disc brakes. No problem!

 

Close-up of the original factory power steering box attached to the driver-side frame rail on an OBS Chevy truck prior to removal.
What we knew Pina’s OBS had was the original steering system, from the box to the column …

 

Disassembled stock OBS Chevy steering box, idler arm, center link, and fluid lines sitting in a green oil drain pan on a shop floor.
… the former of which proved ultimately to be well worn was removed entirely and stored properly.

 

Underside front frame rail mounting holes exposed on an OBS Chevy truck with the sway bar swung down, ready for the Flaming River rack bracket.
With the stock parts removed, we’re left with a semi-fresh canvas in which to work with around the Stone Custom Fab components.

 

Detail view of a yellow zinc-plated Grade 8 mounting bolt and thick washer inserted into the black powder-coated Flaming River steering cradle bracket.
We will note, however, that since the upgraded tie rods use heims rather than tie-rod ends, the Flaming River “travel bar” (centerlink) must have its tapered holes drilled out to 5/8 for the hardware replacing the tapered pins.

 

Technician uncoupling and pulling the original factory intermediate steering shaft out from the engine bay of a teal OBS Chevy truck.
The OE collapsible steering shaft had seen better days, as well, which is to be expected from something that’s been in use since Sammy Hagar shared a stage with Eddie Van Halen!

 

Side-by-side comparison of the aftermarket Flaming River needle-bearing universal joint steering shaft and the bulky stock OBS Chevy rag joint shaft.
No worries—Flaming River supplies a “ragless” stainless slip shaft with a pair of stainless U-joints to mate the power rack to the factory column.

 

Mechanic lifting and positioning the complete Flaming River rack-and-pinion crossmember assembly into place beneath an OBS Chevy chassis.
With all the old out, time to replace with the new—starting with the cradled rack assembly, which locates to existing holes on the box framehorns (the driver side using the leftover steering box mounting holes).

 

Hands aligning the black Flaming River conversion bracket against the factory frame rails of an OBS Chevy truck during installation.
If the front crossmember “snout” poses an issue getting the loaded cradle in place, simply remove the rack-and-pinion temporarily until you’re able to get the cradle nestled in its place.

 

Close-up of a mechanic holding a threaded steering tie rod link with blue painter's tape used to mark cut length and depth measurements.
Little tip that Ryan Manson had to improvise in getting the cradle’s mounting bolts “through” the boxed framerail without pulling out the rest of his hair—taping the bolt to the socket … an age-old busted-knuckles trick!

 

Mechanic bolting the Flaming River rack-and-pinion steering cradle to the front frame of an OBS Chevy pickup on a two-post lift.
Here’s the Flaming River cradle with steering rack mounted to the frame.

 

Close-up of hands aligning the inner tie rod stud and heim joint into the Flaming River center-link rack assembly under an OBS Chevy.
With the rack-and-pinion unit mounted in place, the steering linkage can now be connected to the travel bar.

 

Detailed view of a heavy-duty heim joint tie rod connection bolted securely to the Flaming River steering rack bracket under an OBS truck chassis.
The steering rack is made to the same geometry as the old centerlink. The tie rods (heims in this case) bolt from back to front.

 

Mechanic lifting and securing the Currie Antirock front sway bar into place below the installed Flaming River rack-and-pinion unit on an OBS Chevy.
Last item to be tended to is reinstalling the sway bar, which we had previously determined at the onset (due to its torsion nature) would pose no mounting or operational interference issues.

 

Underside view of an OBS Chevy truck on a lift showing an installed Flaming River rack-and-pinion steering conversion kit with tubular control arms and aftermarket suspension.
The completed main portion of the rack conversion—as you can see, the unit sits nice and high, with its 3/8-inch plate steel cradle assuring zero flex during “non gridlock” (i.e., autocross or canyon carving!) use.

 

Mechanic inspecting the front suspension and Flaming River rack-and-pinion steering setup underneath a teal Chevy OBS pickup raised on a two-post shop lift.
Before moving on up beneath the hood to finish the install, Manson fully articulated the rack to ensure no binding issues with the aftermarket linkage—of which there were none!

 

Comparison of the precision CNC-machined Flaming River universal joint steering shaft against the deteriorated OEM rubber rag joint coupler.
The factory rag joint provided a fixed intermediate shaft mounting; the new FR stainless 3/4-36×3/4-DD U-joint will allow adjustable mounting, if needed (the rack is adjustable on the cradle), for alignment, such as header/exhaust clearance.

 

Macro view of a Flaming River steering universal joint showing needle bearing trunnions, pinch bolts, and set-screw lock nuts.
Something often overlooked but should always be addressed: dimpling the steering shaft for the setscrews once the linkage is measured and cut to size! Don’t forget the thread locker (and trimming down the Allen screw in tight-fit situations).

 

Engine bay view showing the Flaming River intermediate steering shaft and needle-bearing U-joint clearing tubular exhaust headers in an OBS Chevy truck.
Pina’s OBS is running JBA tube headers, which the linkage cleared; factory exhaust manifolds should offer more room to work around.

 

High-pressure braided stainless steel power steering line with AN fittings, metric adapters, and instruction tag for a rack and pinion kit.
Last item to address: power steering plumbing. The factory power steering lines will not work with the steering rack conversion, so the system includes new lines.

 

Top-down view into the engine bay showing braided stainless steel power steering lines connected with AN fittings to the Flaming River rack-and-pinion unit.
Flaming River supplies precut/crimped braided stainless lines and all necessary fittings (including the AN return adapter for the stock PS filter system).

 

Mechanic pouring fresh power steering fluid from a yellow bottle into the pump reservoir of a teal OBS Chevy truck engine bay.
With the plumbing buttoned up, Manson topped off and bled the fluid reservoir, then we did a quick on-the-ground toe-in alignment before testing for any potential fluid leaks (none) and ultimately an initial test drive – Amazing!
Once the conversion is complete, Ruben Pina’s truck made a trip to the alignment shop. After its test drive, Ruben had nothing but high praise for the steering rack’s improved feel and feedback.

 

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