How would you like to have your trailer automatically steer itself behind your truck?

The Truck that started is all, GMC Denali Quadrasteer. Visit www.QuadrasteerClub.com to chat or learn more about the advantages of 4-Wheel-Steer.

This is so exciting it's hard to explain! I wouldn't have believed the deference if I didn't drive it. In my decades of pulling trailers, I thought I had seen it all. It's good to be pleasantly surprised. I put the trucks with trailers through my extreme tests and couldn't get the trailers to whip or dip. The Suburban with the Autoride option was even more impressive. I took the Quadrasteer's on sharp mountain curves and loaded round bales more to the rear of a flatbed trailer to purposely make the trailer sway. That didn't work either. I did these trailer tests on pavement and gravel roads. Each time I tried to make the trailer misbehave, Quadrasteer controlled it.

 
 

The Most Important Improvement to Pulling Trailers since the Weight Distributing Hitch

Delphi Quadrasteer electric rack and pinion steering axle.

It's all about control and safety. Pulling loads in heavy traffic can be scary. And then there are the maneuverability advantages like parking lots. Most mall seem to have designed the parking lots for mini-cars, let alone large trucks.

We had "crab steer" tractors back in the sixties. The 4x4 Case 1200, 1470 and 2670 series tractors would steer the wheels front and rear in the same direction or the opposite direction to turn shorter or offset the draft farming with a one-way plow. It worked great and was controlled by the driver.  In the nineties some sport car manufactures introduced  All-Wheel-steer cars for improved cornering and parking. The problem that caused them to be discontinued was the hydraulic activation. Being controlled by hydraulics, (oil under pressure) these systems would move at different speeds depending on warm the oil was. When cold the steering was slow and faster as it warmed up. That wouldn't  be much fun waiting to warm up each time have a similar steering control.

Delphi announces a reduced price of $1995 for their Quadrasteer option on GM trucks for 2004 models. Now enter Delphi, the electronic guru's. Delphi has corralled the missing links in the Four-Wheel-Steer equation. Using dependable electronic controls instead of inconsistent hydraulic pressure, Delphi has created a safe, heavy-duty system for ultimate vehicle control. Delphi has earned a reputation for top notch electronic controls in the automotive industry, winning contracts with all the manufactures for quality electronics. The best company for the job designed the best system for the job. With safety first, Delphi created a system that could correct itself should a problem arise. With a fail safe neutral, the Quadrasteer unit will return to a stationary straight ahead position if a wire is cut or unplugged returning the truck to  "front wheel" steering only.

(Excerpt from my Quadrasteer article)..."On with the good stuff and itís some very fun good stuff!  I may have to turn down the week I get the Hummer 2 just so I can get a Quadrasteer again. The GMC HD 1500 was a pleasure to drive in traffic with the added driving control that the Quadrasteer system hands you. ........... Iíve not in my many decades driven a better trailering vehicle. Quadrasteer is designed to turn the rear wheels in the opposite direction as the front wheels when driving under 40 mph and it turns the rear wheels the same direction as the front wheels above 40 mph. And in tow mode in Four-Wheel-Steer the rear wheels turns less under 25 mph and more above 25 mph for that great highway speed control...........For an extreme test I hooked the Suburban to a car trailer ... with three big round bales. I loaded it on purpose heavy to the rear for the test to provide some sway action....So somewhere close to 5000#ís of trailer cruising down the old highways of Eastern Colorado at near 80 MPH. I performed evasive maneuvers, (you know swerving between the white dashes in the middle of the road). I couldnít get the trailer to move, sway, buck, or even give a little! It was like the trailer and truck were one unit. The trailer realigned itself behind the Suburban quickly as the Quadrasteer walked sideways as I swerved back and forth trying to find a weakness. Iíve never seen anything like it. Yes Iím in love! I did this on loose gravel roads also and it handled more than superbly. My test with the Quadrasteer turned off, scared me to death on pavement and gravel! ........... I donít suggest you pull a trailer 80 mph, but I know with 75 mph speed limits on Colorado primary highways, there are some of you that do pull this speed and I want to be able to report on this trucks ability to pull in the real world."

Interview with Delphi Engineer Kevin LaVigne

Straight from the engineer's mouth, Kevin LaVigne of Delphi answered some questions for me on the phone. There have been several good articles written about Quadrasteer and Delphi's website does a great job of explaining the details involved at Click  I ask the questions I haven't seen anywhere.

MT: Is Quadrasteer different from the cars that had all-wheel-steer in the early nineties?

KL: Yes, Delphi's QUADRASTEER Four-Wheel-Steering System is electronically controlled whereas the earlier four wheel steer systems were mechanically. Earlier systems also turned the rear wheels at a smaller angle. QUADRASTEER has been designed to turn at a large angle, up to 12 degrees, specifically for full size vehicles.

MT: Are the CV joints in the rear Dana 60 axle with Quadrasteer, heavy duty?

KL: Yes, the quartershaft assembly has a tripot joint which allows the assembly to withstand torque levels similar to HD 2500 applications. The ring gear in the rear axle is a 9 3/4 inch.

MT: Can you use overload springs on the rear axle with Quadrasteer?

KL: Overload springs or air bags have been used with QUADRASTEER. When making changes to your vehicle such as this though, you may be voiding your warranty. Be sure to check with your GM dealer.

MT: Do you have to align all four wheels with Quadrasteer as you would with a front wheel drive car?

KL: A vehicle equipped with QUADRASTEER can become misaligned in the rear. There is a mechanical alignment required. The only mechanical adjustment is the toe setting. The caster-camber is non-adjustable. A quick electrical alignment is also required and must be done by a GM qualified service technician.

Click to see where it started at Delphi's website.

And for the explanation page to understand it click.

Take a test drive pulling a trailer. More dealers are understanding the value of a trailer test drive and accommodating.

Quadrasteer uses conventional front-wheel hydraulic power steering in combination with an electrically powered rear wheel steering system, to adjust rear-wheel angles, turning them opposite to the front wheels at lower speeds and in the same direction as the front wheels at higher speeds, for amazing maneuverability and control. At lower speeds, the system reduces curb-to-curb turning diameter by 21% to 37.4 ft., which is about the same as a compact car. You'll love them in parking lots. At highway speeds, Quadrasteer reduces yaw to improve stability, providing safer, more confident, lane changes, passing and evasive maneuvers, especially in wet or windy conditions. The increase in trailering control is equally amazing. With Quadrasteer, truck and trailer move down the highway almost like a single unit. You can change lanes more quickly and safely with hardly any trailer sway even at 70 mph with a 6,000-lb. trailer.

Read my article on the Quadrasteer Suburban and GMC HD 1500 Click...

Visit www.QuadrasteerClub.com to chat or learn more about the advantages of 4-Wheel-Steer.

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