Quadrasteer question

colosilverado · February 12, 2002

I was responding to a question in the 1500 section about the 03's and started wondering.

If you get a truck with the quadrasteer, can you even put bigger tires on it? Will that mess up the quadrasteer or does the physical makeup of the quadrasteer make it impossible to fit anything bigger?

I'm sure someone already addressed this, but I missed it.

CMNTMXR81 · February 12, 2002

I don't know how many degrees of rotation the rear wheels turn, but I know the wheel well depth in back isn't as deep as the front, so I'd be concerned with rubbing on the wall of the bed where it meets the frame. But it all depends on that degree of rotation.

Jpshostr · February 12, 2002

I think it would involve just how much those tires turn and what kind of sweep they take the tires through in the wheel well. I assume they have opened it up more than the regular axle in the back (I've not seen one), but I still don't think it is as much as in front. I'd guess this is one of those wait and see things. I'm sure it could be done, how much hassle it will be is going to be the question.

boycer11 · February 12, 2002

I was wanting it on the 2500 HD, but from what I hear, it will not happen yet. I also asked on another site (won't say which) if you could put a lift on and add bigger tires. They seemed to think that a new lift would have to be designed. I am in the wait and see mode. Trying to decide between: seiraa denali, 2500 HD, new Escalade, or see if GM is going to get some balls and make an SS. Would like to have quadrasteer and that new deplacement on demand engine. Course I woundered if the DOD engine could work with a supercharger

mark

CMNTMXR81 · February 12, 2002

Boycer, I don't think you'll see Quadrasteer on an HD at least for a few years. I think it in part would have to do with sacraficing payload and towing capacity to make it feasible.

chevy4x4trucks · February 12, 2002

Just thought this pic may help some of you, it's a shot of the quadrasteer:

hoot · February 12, 2002

I think it's maximum 12 degrees.

TxDoc · February 12, 2002

Quadrasteer adjusts rear-wheel angles up to 12 degrees, turning them opposite to the front wheels at lower speeds.

Just some more info:

http://www.caroptionsonline.com/gerry_q.htm

http://cincinnati.com/2002autopreview/columns/vansickle.html

boycer11 · February 12, 2002

The Seirra Denali with quadrasteer is rated at 10,000 towing compacity. That does not to bad. I want to wait and see how many problems they have with the quadrasteer first. Something tells me that there will be problems knowing gm.

colosilverado · February 13, 2002

Yeah, I would imagine that there'll be some little quirks to work out of it, so I'll wait and see.

Great pic, BTW!

CMNTMXR81 · February 13, 2002

I would take that tow rating with a grain of salt still though. Think about it. You have weight being centered over now what is a moving rear axle ends, which could cause excessive wear on whatever bearings and CV joints are on the end. Not saying it can't do it, but knowing GM, I'm surprised they didn't drop it to 8,500lb rating just to be on the safe side.

Has anyone measured if 12 degrees would be enough to rub the inner box wall and frame?

That picture almost makes it look like it has two pumpkins.

boycer11 · February 13, 2002

I wonder if you can just turn it off if it breaks, how long it would take a dealership to fix it if it broke, and can you imagine how much they would probably charge you if it broke and was not under warranty. I would want an exstended warranty on that for sure. But from what I have read it handles a lot better.

Mark

CMNTMXR81 · February 13, 2002

I think I remember reading somewhere that there is a lock switch which keeps them locked straight. So if it breaks, I'm sure this would work.

But yea, definetely one more thing to go wrong.

chevy4x4trucks · February 13, 2002

Take a look at this pic, on the dash where the 4 pod housing is there's a rectangle in white w/ 4 smaller recangles that are angled. That's the quadrasteer engage/disengage switch:

TxDoc · February 13, 2002

Several pics:

Pic 1 Dash

Pic 2 Differrent Wheel Angles

Left Front View

Yes, you can turn it off. If the computers don't agree that it is functioning correctly, it will automatically disengage. This has been in developement and not something that was designed and made since last year.

"Quadrasteer steer-by-wire rear axle is controlled by two sophisticated microprocessors. At low speeds the rear wheels turn in the opposite, or negative, direction of the front wheels up to a transition zone of around 40 to 45 mph where the rear wheels track neutrally. At speeds over 45 mph the rear wheels turn in concert, or positively, with the front. If at any time the two microprocessors 'disagree' over the steering information they have received QS4 automatically shuts down and reverts back to traditional two-wheel steering.

Located on the dash of the Sierra Denali is a push button Quadrasteer control panel similar to the four-wheel drive control panel found in many trucks today. The driver pushes the button to change steering modes from two-wheel steer (2WS) to four-wheel steer (4WS) to four-wheel steer tow (4WS TOW). In 4WS mode the rear wheels turn up to the maximum allowable amount below 40-45 mph. The wheels transition and turn in the same direction as the front above this speed. When towing, Denali drivers can select 4WS TOW. 4WS TOW reduces the amount of rear wheel steer at slower speeds, when the wheels are turning in opposite directions, but increases it at higher speeds when the wheels turn in the same direction".

"An interesting demonstration of rear wheel movement was shown in response to increased throttle while holding the brake on. Quadrasteer is also sensitive to throttle response not steering alone. 4WS TOW angles ranged from 7 degrees, increasing to 12 with full lock for low speed maneuvers. Reversing the truck lowered the tolerances and reduced the steering angles available for maneuvering the truck. Not that it was a rally course, but rounding the cones at a decent clip seemed to make trailering easier than maneuvering at very low speeds".

"Rodden remarked that during separate road testing on highways in high wind conditions in 4WS TOW mode the truck / trailer combo was also much more stable than in standard 2WS mode".

"At highway speeds with ordinary two-wheel steering, a rotational movement or "yaw" is introduced during turning maneuvers, and is most noticeable during quick maneuvers at high speeds. Since both front and rear wheels turn in the same direction at highway speeds, Quadrasteer reduces "yaw," or rotational motion, for dramatically improved stability. It provides safer, more confident lane changes, passing and evasive maneuvers -- especially during wet or windy weather. It's almost like sliding from side to side, instead of turning".

"On a simulated off-road course, where trees and boulders were replaced with orange pylons, our test truck was able to jockey around easily because its rear wheels maintained the same clearance as the front wheels. In the real world, it will allow drivers to venture into places that would stop conventional vehicles short, such as narrow mountain roads and hairpin turns".

"The increase in trailering control is even more impressive. With conventional steering, turning the towing vehicle introduces an unwanted turning movement into the trailer. Quick maneuvers can cause genuine white-knuckle moments when the trailer begins to sway back and forth. Trailer owners have been known to spend plenty of time, effort and money installing aftermarket devices to control these oscillations".

"Quadrasteer allows the truck and trailer to move down the highway as if they were one because the destabilizing turning motion is eliminated. Drivers can change lanes more quickly and safely with hardly any trailer sway -- and according to GMC, even at speeds of 65 mph and with an 8,000-pound trailer".

"In a crowded parking lot, Quadrasteer allowed our test truck to pull its trailer around a corner without climbing over a curb. It also allowed us to maneuver its trailer easily in tight spaces, like a boat launching area or at a campsite, or to back the trailer up without the normal right and left gyrations accompanying such a maneuver".