Nowadays with the smartphone in your pocket connected to your truck’s Bluetooth it can be hard to imagine a time when trucks and 4x4s came from the factory with manual drum brakes on all four corners and manual “strong arm” steering. Those days are long gone, but the simple and bulletproof trucks of those bygone eras are still on the road and trails. As it turns out, adding power steering and modern brakes is simple and greatly improves the performance of any old 4x4.
One such truck ripe for these simple upgrades is our 1970 half-ton 4x4 Chevy Suburban known as Dino (“1970 Suburban Rescue Mission”). Dino is very simple with a 350ci V-8, manual transmission, solid axles, ladder frame, and a gear-driven T-case. We don’t need to talk to Dino via Bluetooth—it knows what to do. We like simple, but manual steering gets old fast off-road, and it is hard to believe Dino made it almost 46 years without an upgrade to the old steering system. We’re going to start with a power steering swap, but also have plans for disc brakes and more upgrades that will help this eclectic SUV on the road and trail. Lucky for us, swapping power steering onto Dino is fairly simple since round-fender, three-door Suburbans did come from the factory with power steering. These SUVs also share much of their design with early Blazers and Chevy or GMC 4x4 trucks, so all of this tech will help you even if you don’t have a Suburban like Dino and the general idea of the swap is the same for just about any 4x4 that came from the factory without power steering, be it a Jeep, Dodge, Ford, or Japanese 4x4.
The easiest way to do any power steering conversion is to start with a parts vehicle. You should grab all the components you might need, including brackets and pulleys if you can find them. Chevy V-8s from the 1960s through the 1980s that use V-belts are either short water pump or long water pump; Dino has a short water pump. We sourced brackets, a pump, and pulleys from a local 1947-1987 GMC and Chevy truck specialist called Truckin’ Krazy.
Later we bumped into this round-fender 4x4 3/4-ton truck at a self-service junkyard. Someone had already taken the steering shaft, but we snagged the used power steering box, rag joint, and pitman arm. We left the power steering brackets and pulleys because we already had the pump, brackets, and pulleys at home.
Here is Dino’s manual steering box. It served this dinosaur well, but power steering is a simple upgrade basically bolting in place. We were able to reuse Dino’s steering shaft with part of the rag joint from the junkyard. The manual steering gear rag joint won’t fit a power box (more on that later).
If you own an older Chevy or GMC truck or other 4x4, bolting on a power box is only possible if the mounting area of the frame is stamped like Dino’s shown here with some relief. The mounting surface on the back of the box is not flat, so if your manual box bolted flat against the frame you will need to fabricate a proper mount. You can do this with a hole saw and heavy-wall tubing welded in place on a flat or boxed frame.
Next, we pulled the fan shroud, fan, water pump pulleys, and crankshaft pulleys and test-fitted the power steering brackets and power steering pump on the Chevy 350. Two bolts secure the bracket to the engine block, and part of the bracket reaches back to one of the motor mount bolts. We also used the power steering pump from Truckin’ Krazy as a core on a remanufactured pump from our local parts store.
With a rag joint rebuild kit from Dorman we were able to reuse the manual steering intermediate shaft with part of the rag joint from the power box we pulled from the junkyard, although we did find a replacement rag joint for a 1970 Suburban with power steering available from LMC Truck. The extralong input shaft of the manual box allows the rag joint to be in about the same spot with both the manual and power steering gear box.
We had to track down two new fan belts: one to run the power steering pump and a new belt for the alternator because the replacement water pump pulley we ended up with was smaller than Dino’s original. Most parts store V-belts list their outside circumference, (oc) on the packaging. By using a fabric tape measure to follow the route around the outside of pulleys, you can get a pretty good estimate of how long a fan belt you are going to need.
The return line on the power steering system doesn’t use a premade hose but requires about 3 feet of power steering return hose (available at most any parts store) and a fitting for the box. The fitting on the junkyard box was damaged, but we were able to chase down the fitting from our local parts store. We did need to add a 90 degree bend, and it’s awfully close to the fender. We will keep our eye on the fitting to make sure it doesn’t get damaged. Also note our new reman’d power steering gear. We could have reused the junkyard power steering gear, but it was almost guaranteed to leak (since it was coated in oil and dirt). We were glad we had it though, as the core charge for a 1970 power steering gear was $75.
With everything bolted in place and fan belts in hand we were able to put Dino’s accessories back together and install new high-pressure and return line from our local parts store. We routed the hoses where they wouldn’t get cut on Dino’s fender or frame and zip-tied them together to keep them from moving around too much.
Dino’s factory steering wheel has seen a lot and hasn’t aged well. Big chunks of 46-year-old plastic were falling from the wheel to the floor soon after we got the truck. On top of that, someone in Dino’s past decided to repair the wheel with duct tape. Duct tape doesn’t last too well when sweat and oils from your hand meet it, and as a result the wheel was sticky to the touch. Yuck! Luckily for us LMC Truck carries a brand-new steering wheel for these trucks, and we couldn’t wait for a planned interior refresh story to replace Dino’s wheel. With the LMC Truck’s wheel in place, Dino’s power steering conversion feels all new for many reasons.