IF GMC's are Professionally Engineered, how come no one buys them....?

[Mani]

Originally posted by: WinkOsmosis

Originally posted by: Mani

Originally posted by: Lifer
4 wheel steering is not new.
I believe some other cars have had over a decade ago, maybe late 80's early 90's, or possibly even earlier.

Prelude

That's a completely different thing. Four wheel steering on the Prelude, 3000gt, 240sx, was just a little thing that angled the rear wheels to a max of like 3° in the same direction as the front. I believe GM's system is ACTUAL STEERING. At low speed, like parking lot speed, it actually helps the steering by turning in the opposite direction from the front wheels. "

Uh...no it isn't. The Prelude's 4WS worked the same way...it would turn the wheels in the same direction for high speed lane changing and turned them in the opposite direction for low-speed turning.

 

[iamwiz82]

lots of companies offer locking diffs. The Jeep Wrangler Rubicon has front and rear air-actuated locking diffs. Toyota offers it with their TRD packages, as do H2's.

 

[Goosemaster]

Interesting stuff...

 

[RayH]

Originally posted by: Mani

Originally posted by: WinkOsmosis

Originally posted by: Mani

Originally posted by: Lifer
4 wheel steering is not new.
I believe some other cars have had over a decade ago, maybe late 80's early 90's, or possibly even earlier.

Prelude

That's a completely different thing. Four wheel steering on the Prelude, 3000gt, 240sx, was just a little thing that angled the rear wheels to a max of like 3° in the same direction as the front. I believe GM's system is ACTUAL STEERING. At low speed, like parking lot speed, it actually helps the steering by turning in the opposite direction from the front wheels. "

Uh...no it isn't. The Prelude's 4WS worked the same way...it would turn the wheels in the same direction for high speed lane changing and turned them in the opposite direction for low-speed turning.

The 80's Preludes 4WS worked on steering angle. At low angles the rear wheels turned in the same direction as the front. As you turned the steering wheel further, the rear wheels turned in the opposite direction as the front.

 

[Howard]

Originally posted by: RayH

Originally posted by: Mani

Originally posted by: WinkOsmosis

Originally posted by: Mani

Originally posted by: Lifer
4 wheel steering is not new.
I believe some other cars have had over a decade ago, maybe late 80's early 90's, or possibly even earlier.

Prelude

That's a completely different thing. Four wheel steering on the Prelude, 3000gt, 240sx, was just a little thing that angled the rear wheels to a max of like 3° in the same direction as the front. I believe GM's system is ACTUAL STEERING. At low speed, like parking lot speed, it actually helps the steering by turning in the opposite direction from the front wheels. "

Uh...no it isn't. The Prelude's 4WS worked the same way...it would turn the wheels in the same direction for high speed lane changing and turned them in the opposite direction for low-speed turning.

The 80's Preludes 4WS worked on steering angle. At low angles the rear wheels turned in the same direction as the front. As you turned the steering wheel further, the rear wheels turned in the opposite direction as the front.

Nope. At low speeds the steering response was sharpened by having the rear wheels turn in the opposite direction. At higher speeds, presumably to make lane-changing more stable, they made the rear wheels turn in the same direction as the front wheels.

 

[Angrymarshmello]

Originally posted by: Howard

Originally posted by: RayH

Originally posted by: Mani

Originally posted by: WinkOsmosis

Originally posted by: Mani

Originally posted by: Lifer
4 wheel steering is not new.
I believe some other cars have had over a decade ago, maybe late 80's early 90's, or possibly even earlier.

Prelude

That's a completely different thing. Four wheel steering on the Prelude, 3000gt, 240sx, was just a little thing that angled the rear wheels to a max of like 3° in the same direction as the front. I believe GM's system is ACTUAL STEERING. At low speed, like parking lot speed, it actually helps the steering by turning in the opposite direction from the front wheels. "

Uh...no it isn't. The Prelude's 4WS worked the same way...it would turn the wheels in the same direction for high speed lane changing and turned them in the opposite direction for low-speed turning.

The 80's Preludes 4WS worked on steering angle. At low angles the rear wheels turned in the same direction as the front. As you turned the steering wheel further, the rear wheels turned in the opposite direction as the front.

Nope. At low speeds the steering response was sharpened by having the rear wheels turn in the opposite direction. At higher speeds, presumably to make lane-changing more stable, they made the rear wheels turn in the same direction as the front wheels.

According to this article you're wrong

 

[PricklyPete]

I bought a 2002 GMC Yukon last year....and thought it was great (except the interior is not quite up to other $40K vehicles). I sold it this year because my commute was getting out of hand and I was paying $250 in gas for a truck I really didn't need (plus I was still able to make a few grand off the sale...so that helped motivate me). Otherwise I would still be driving that beast.

 

[Mani]

Originally posted by: Howard

Originally posted by: RayH

Originally posted by: Mani

Originally posted by: WinkOsmosis

Originally posted by: Mani

Originally posted by: Lifer
4 wheel steering is not new.
I believe some other cars have had over a decade ago, maybe late 80's early 90's, or possibly even earlier.

Prelude

That's a completely different thing. Four wheel steering on the Prelude, 3000gt, 240sx, was just a little thing that angled the rear wheels to a max of like 3° in the same direction as the front. I believe GM's system is ACTUAL STEERING. At low speed, like parking lot speed, it actually helps the steering by turning in the opposite direction from the front wheels. "

Uh...no it isn't. The Prelude's 4WS worked the same way...it would turn the wheels in the same direction for high speed lane changing and turned them in the opposite direction for low-speed turning.

The 80's Preludes 4WS worked on steering angle. At low angles the rear wheels turned in the same direction as the front. As you turned the steering wheel further, the rear wheels turned in the opposite direction as the front.

Nope. At low speeds the steering response was sharpened by having the rear wheels turn in the opposite direction. At higher speeds, presumably to make lane-changing more stable, they made the rear wheels turn in the same direction as the front wheels.

You're both right. At low speeds (high angle) the rear wheels turned in the opposite direction to make a smaller turning radius. At higher speeds (lower angles) the rears turned the same direction. The original 4WS ludes were based on how much you turned the wheel and was purely mechanical. Later models had electrical assist.

 

[Pacfanweb]

Originally posted by: Cyberian

Originally posted by: Pacfanweb

Locking rear-differential
This is pretty cool(even better than limited-slip)

They are the same thing. All Limited Slips, Posi Tracs, etc. are locking differentials. Some go about doing the locking in different ways, but they accomplish the same thing.
Limited Slip, Posi Trac, Saf T Trac, Traction Lok, etc, are just catchy names manufacturers come up with.

You sure about that?
I always thought that Positraction was a 'limited slip' and a locking rear differential was 'no slip' or locked.

Yes, I'm sure.

A LOCKING diff. is one that can unlock or slip internally to enable a vehicle to go around corners without screeching the tires and making lots of noise. Diffenent names for LOCKING diffs., as I mentioned before, are Positive Traction, Posi Trac, Trac Loc, Traction Lock, Sur Grip, Saf T Trac, Limited Slip.
These all do the exact same thing, which is connect the axles when moving straight for maximum traction, and let them disconnect or spin at different speeds for cornering.

A LOCKED diff. is completely locked at all times. Most all drag cars have one. They are usually called spools. A spool is a piece of hardware with no moving parts. The ring gear bolts on, the axles slide in....and they either turn, the tires spin, or something breaks. No cars are built with them.

 

[GroundZero]

gmc trucks are cost more because of the heavier construction, i know many people that own them. they are way better than any ford or chevy especialy if you want a work truck. more people would probably buy them if they weren't such cheapskates. also why pay more for a truck that is pretty much the same as a chevy except for the suspension and running gear? most people don't need a work truck.

 

[iamwiz82]

Originally posted by: Pacfanweb

Originally posted by: Cyberian

Originally posted by: Pacfanweb

Locking rear-differential
This is pretty cool(even better than limited-slip)

They are the same thing. All Limited Slips, Posi Tracs, etc. are locking differentials. Some go about doing the locking in different ways, but they accomplish the same thing.
Limited Slip, Posi Trac, Saf T Trac, Traction Lok, etc, are just catchy names manufacturers come up with.

You sure about that?
I always thought that Positraction was a 'limited slip' and a locking rear differential was 'no slip' or locked.

Yes, I'm sure.

A LOCKING diff. is one that can unlock or slip internally to enable a vehicle to go around corners without screeching the tires and making lots of noise. Diffenent names for LOCKING diffs., as I mentioned before, are Positive Traction, Posi Trac, Trac Loc, Traction Lock, Sur Grip, Saf T Trac, Limited Slip.
These all do the exact same thing, which is connect the axles when moving straight for maximum traction, and let them disconnect or spin at different speeds for cornering.

A LOCKED diff. is completely locked at all times. Most all drag cars have one. They are usually called spools. A spool is a piece of hardware with no moving parts. The ring gear bolts on, the axles slide in....and they either turn, the tires spin, or something breaks. No cars are built with them.

LSDs and positraction(they are the same, posi is a GM trademark) work by giving the most torque to the wheel that is slipping the least. While it still locks by transferring power to both wheels, even when one is slipping, it just gives more power to the one that isnt slipping. This is usually done without using gears.

Lockers lock the wheels together no matter what. You can either get automatic lockers or manual lockers. Auto lockers work by engaging when there is power given to the driveshaft. When not on the gas, the locker will disengage. Therefore, making a turn while giving the vehicle gas causes lots of noise(tires and banging). When not on the gas and turning, you will hear a clicking from the locker. A manual locker has a switch to disconnect the locking mechanism. This can be done with electricity or air. Lockers are gear driven, normally.


The finally version, like Pacfanweb said, is a spool. There are 2 types of spool, full spool and mini spool. A full spool is a one piece gear which replaces the side gears in the diff. This replaces the entire carrier. A mini spool is a device that is installed in the original carrier of the diff that stops the differentiating of the wheels without replacing the entire center section.