STEER YOU RIGHT
Four Wheeler|January 2021
A PSC Motorsports Big Bore XD steering box solved our Jeep’s steering woes
Harry Wagner

These days, 40-inch tires seem like the norm, and it isn’t uncommon for people to install hydraulic-assist steering on their street-driven 4x4s (or full hydraulic on trail-only-buggies). Our ’06 LJ has 37-inch tires and the factory steering system definitely didn’t like to turn them when they were aired down on the trail. We assumed that we needed hydraulic-assist steering, but after talking to Tom Allen at PSC Motorsports he explained that might not be the case. PSC Motorsports offers a whole host of options for ’87-current Jeep Wranglers.

Given our tire size and the amount of road miles we drive, Allen recommended the company’s Big Bore XD replacement steering box. The Big Bore box is a bolt-on upgrade for ’03-’06 Wranglers that replaces the factory ZF steering box. A German steering box on a Jeep? You may recall that in 2003, Mercedes-Benz purchased Chrysler, and at that time they switched steering box suppliers from Delphi to ZF. “These are the same basic boxes that Mercedes put on passenger cars in the ’80s,” Allen revealed. So, PSC offers an all-new 8200 Series box with a larger-diameter piston to increase torque output and a ported internal valve skirt and custom-machined torsion bar.

We had initially suggested that we could perhaps use a fish scale to measure the steering effort necessary to turn the factory box and the new Big Bore XD box. “I can make you a box that is super easy to turn, but I don’t think you will like it on the road,” Allen cautioned. “That is a function of the torsion bar in the steering box, it changes the steering effort, but has zero effect on the output torque.” Just like in a suspension system, the thickness of the torsion bar in your steering box affects its resistance to twisting. The torsion bar in the steering box slides inside the input shaft and is twisted when the steering wheel is turned. PSC sent us two Big Bore XD steering boxes with different torsion bar thickness so we could test them for ourselves. And like Allen warned, the lighter steering effort seemed great at first blush in the parking lot, but at higher speeds the lack of road feel had us making constant corrections.

We also learned that “steering system” is an important term during our conversations with Allen. “There are a number of factors that will affect steering effort and strength,” he explained. “Yes, you can just add a big hydraulic ram, but that could also result in slow steering and cavitation if you just slap it on to your current steering system.” We added a CBR-style steering pump from PSC after installing the new Big Bore XD box to complete our steering system. The new pump is considerably quieter than our stock steering pump was when turning aired-down 37-inch tires in the rocks. Our new steering system works just as well on the street, too, and we love that it is scalable should we decide to add a hydraulic-assist ram in the future.

Continue reading your story on the app

Continue reading your story in the magazine

MORE STORIES FROM FOUR WHEELERView All

THE DOMINO EFFECT

Budget fixes for some GM IFS woes

2 mins read
Four Wheeler
February 2021

ULTIMATE ADVENTURE

PART 2: WILDLIFE, NATIONAL TREASURES, AND EXTREME WHEELING

9 mins read
Four Wheeler
February 2021

THE 2020 ULTIMATE ADVENTURE: LONG RANGE JEEP

Part 2: Steering, control arms, and mounting the drivetrain

9 mins read
Four Wheeler
February 2021

Long-lost Scout photos

During some overdue office rearranging, I recently unearthed a long-lost photo album that I had forgotten about.

1 min read
Four Wheeler
February 2021

Transcontinental

A Cummins-powered Jeep that spent two years in the African bush, and beyond

4 mins read
Four Wheeler
February 2021

TRAVEL TOY

Snow, sand, and mud—Joel Lawrence’s 4Runner does it all with an M101 trailer in tow

3 mins read
Four Wheeler
February 2021

OVERSEAS DANA 44 FOR A YJ

OVERSEAS DANA 44 FOR A YJ

4 mins read
Four Wheeler
February 2021

Precursor to luxury: Looking back to the Kaiser Jeep Super Wagoneer

As we put hands to keyboard on this issue of Four Wheeler, Jeep has only begun to tease us with its latest entry in the premium luxury SUV field: the Grand Wagoneer concept.

2 mins read
Four Wheeler
February 2021

CORROSION EXPLOSION

What we found on our 15-year-old truck when it came time to replace the brakes and exhaust

3 mins read
Four Wheeler
February 2021

2020 Ford F-250 Super Duty Limited

First Report: 1,050 lb-ft of pulling power and a $90,000 price tag

5 mins read
Four Wheeler
February 2021
RELATED STORIES

Suddenly, the possibilities seem endless

After Josh Allen sprinted into the end zone for the second time, Vic Fangio had his made-for-TV moment.

4 mins read
Bills Digest
January 4, 2021

Five hot topics Bills fans are talking about

Bills Digest editor Mark Ludwiczak and editor-at-large Chris Brown weigh in on a handful of the hottest subjects Bills fans have been sounding off about in e-mails to our offices, radio call-in shows and Internet message boards. Have an opinion? Feel free to send an email to Chris (AskChris@bills.nfl.net) or Mark (Mark@asmpublishing.com).

5 mins read
Bills Digest
January 4, 2021

Benchmark

MERCEDES RE-ESTABLISHES THE THREE-POINTED STAR AS THE SYMBOL OF THE LUXURY SEDAN

10 mins read
Motor Trend
January 2021

FORWARD PROGRESS

Bills control AFC East at season's halfway point

9 mins read
Bills Digest
November 15, 2020

All That Jazz

Fender’s beloved Jazz Bass hits 60 years old this year. We meet Allen Abbassi, Senior Product Development Manager, for a look back—and forward—on the subject of the mighty J...

6 mins read
Bass Player
December 2020

What Bills Fans are saying

Bills Digest scanned the Bills’ Facebook site to gauge the hot topics fans are talking about. We chose some of the better posts, edited for brevity and clarity, and present them here, along with Bills Digest editor Mark Ludwiczak’s take on what’s being discussed.

5 mins read
Bills Digest
December 07, 2020

Allen leads, perseveres after grandma's passing

In many ways, Josh Allen’s performance against the Seattle Seahawks was one for the record books.

1 min read
Bills Digest
December 07, 2020

Miracle stings, but shouldn't derail Bills

After Buffalo’s playoff loss to the Houston Texans last season, Josh Allen said it would take a long, long time to get over it.

5 mins read
Bills Digest
December 07, 2020

2002 Jeep Wagoneer Concept

Worth the wait?

4 mins read
Motor Trend
December 2020

Alpha Wolff

Mercedes-AMG Petronas F1 Team Principal Toto Wolff has the winning formula

7 mins read
Maxim
November - December 2020