I just saw the add on TV with that rear wheel steering, dam thats some crazy stuff, pretty cool thow

wonder what axels it's using 60s maybe :confused:

yeah its very cool although i cant see any future for the technology that they use in the wheeling arena. the rear wheels turn such a small degree in comparison to the fronts, and im sure that the linkages that they use arent up to the task.

kick ass for a tow rig, though. too bad that that truck costs so much $$$

No such thing as a cheap truck nowadays! That truck would be sweet for trailers and boats........:skull:

I saw a little test they did on one on tv the other day. They were towing a trailer w/a new GMC w/the rear steer on, did a quick swerve, looked to handle real well. Then they turned it off and repeated the test, I thought they were gonna lose it, the trailer was flying. I sure wouldn't mind being able to nose my ex cab long box into a parking space sometimes.

Pete

Originally posted by Chief Yelling Alot
I just saw the add on TV with that rear wheel steering, dam thats some crazy stuff, pretty cool thow

wonder what axels it's using 60s maybe :confused:

Yes the rear steer axle is a Dana 60.

Quadrasteer.

New in 2003 on G.M.C. (2002, models?), I think it will be avalible across the line in the following years.

In a nut shell,
it uses steering wheel position sensor, vehicle speed sensor (as-well as several others sensors) to detirmin when, how much and in what direction to turn the rear wheels. It also has a feed-back sys to indentifie the postion of the rear wheels and it's performance (for detecting faults).

The driver can select one of three possible modes from a dash mounted switch.

- 2-wheel steering.
Normal steering, rear wheel steering is disabled.

- 4-wheel steering. (normal)
In this position the sys will turn the wheels in the oppisite dircetion (negative) of the front wheels in low speeds, it will gradualy reduse rear steer as speeds increase. At aproximatly 40 mph the sys is in "neutral". As speeds increase past 40 mph, the rear wheels will turn with the front wheels (positive).

- 4-wheel steering, tow-mode.
About the same as above. Except, in this mode the sys will increase the amount of positive rear steer (rear wheels will turn with the fronts and more-so, than in the "normal rear steer). Also the cross-over speed, the neutral speed, is also decreased to 25 mph.

*As far as I know*
The rear axle is a "beefed-up" 14-bolt SEMI-floater. The ring gear diameter is increase from 9.5" to 9.74" and ofcource being rear steer, is now a full-floater.

The rear rack-and-pinion is moved with a electric motor with a centering spring, and they are mounted to the bum-cover.

Maximum rear steer is 12 degrees in both diraction.
In reverse, rear steer is limited to 5 degrees.
At a stop, rear steer is limited to 5 degrees.

When will it be avaiable???? I need a new rig now but would really like the rear steer...

Originally posted by BigDan
When will it be avaiable???? I need a new rig now but would really like the rear steer...

It's available now, but only with the Denali package (starting at about $44k :eek: ). Will be available on others in the line in 2003.

TEX

I read an article where the rear axle is going to be a dana 60. I'll go home and see if I can find out what mag and what article, but I was pleasantly surprised to read that.

But it's probaly got a spline count of about 4 the way they're building trucks now days.

Originally posted by BlueJeep
I read an article where the rear axle is going to be a dana 60. I'll go home and see if I can find out what mag and what article, but I was pleasantly surprised to read that.

They needed something that was a full-floater since it steers. Plus, they needed a larger-than-normal ring gear for a 1/2 ton since the Denali has 325HP. But, being a 1/2 ton, a rear-steer version of the FF 14-bolt would have been overkill. Probably why they ended up outsourcing & getting a 60.

TEX

IIRC they aren't making the 14BFF anymore for the new trucks anyways.

Squash

This is from SI2000 (G.M. service manual)

"The axle assemble is a heavier duty version of the STANDERD rear axle on a NON-rear steer truck. The carrier is a 9.74 inch ring and pinion with a 4:10 gear ratio. The quarter shafts are a special heavy duty design with up to 15 deg. of mevement from the C/V joint."

To me, that sounds like they used a 14-bolt, SEMI-floater (9.5" ring gear) and increase the ring-gear to 9.74" and converted it to rear steer.

All steering axles are full-floaters

The normal 14-bolt Full floater is still avalible for some applications.

I'm signing up for the calss as soon as I can, Let ya' all know if there is anything worth reporting.

Originally posted by Realsquash
IIRC they aren't making the 14BFF anymore for the new trucks anyways.

Squash

My 2002 GMC 2500HD has a FF 14-bolt rear. That's what they use with the 2500HD's that have the Vortec 6000 engine & also in the 5-speed 2500 trucks (2500's with AT's get the 9.5" SF). The Duramax & 8100 trucks get the larger 11.5" rear.

TEX

Here we go:

http://www.dana.com/news/pressreleases/prpage.asp?page=799