'04 Z71 Limited Slip

Xao · February 17, 2005

I read somewhere that some 4x4's when engaged really only have two wheels engaged (ie: Front left and right rear).

My question is I have an '04 Silverado Z71 with a 5.3 and a 3.73 limited slip rear, does my 4x4 engage all four wheels in 4wd, or is it alternating front and rear?

rikhek · February 17, 2005

One front will get power and both rear will have power if loss of traction to one of the rears warrants. In other words, 3 wheel drive.

PeterbiltChrome · February 17, 2005

you got it~ 4x4's without the rear locker or posi have one in front and one in the rear spinning in poor traction.

Xao · February 17, 2005

One front will get power and both rear will have power if loss of traction to one of the rears warrants. In other words, 3 wheel drive.

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Just curious what is the logic behind this? Why not have all 4?

Is it to prevent the (what I call "humping") when you have 4wd engaged on dry pavement and turning in a tight circle?

Hi my name is Xao and I have a 3x4.

asilverblazer · February 17, 2005

It is to prevent "humping" as you call it especially on the front which is significantly weaker. They are called four wheel drive because any of the 4 wheels can deliver power at any given time. Unfortunately the tires you don't want the power going to are the ones that usually get it. The limited slip really helps counter this in the rear, and the weight on the front helps both of those tires get enough traction to prevent one from spinning wildly while the other sits idle.

99-2door · February 17, 2005

Can you imagine trying to turn without the front wheels being allowed a differential in speed?

A locked front-end is only usuable in mud bogs or something. I sure wouldn't want it in a street driven vehicle.

mudbug660 · February 17, 2005

I would say with the limited slip in the rear it is a 2 1/2x4 wheel drive. Now if you put a true locker in the rear then you could call it a 3x4.

Xao · February 18, 2005

Can you imagine trying to turn without the front wheels being allowed a differential in speed?

A locked front-end is only usuable in mud bogs or something. I sure wouldn't want it in a street driven vehicle.

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Then out of curiousity, how do these AWD vehicles work? Are they the same setup, just different terminology?

asilverblazer · February 18, 2005

In short yes. Not knowing the specifics on them but if both differentials are open, no limited slip, or locker, then in low traction situations only one front and one rear tire will spin. Keep in mind I have seen an open rear end spin both tires when traction is very poor due to neither tire gaining any traction over the other.

In my opinion 3x4 is a good description of a truck with the "G80" limited slip, while at first one tire may spin, once it engages both rear tires are forced to spin equivalent amounts by the clutch packs, thus each axle shaft is equally delivering power to the tires. If you call it "locked" or not regardless both rear tires are propelling the vehicle equally, along with one in front, 3 tires out of 4 tires = 3x4.

As for other "limited slips", or "lockers" I have no opinion as I don't know how they work.

mudbug660 · February 18, 2005

Can you imagine trying to turn without the front wheels being allowed a differential in speed?

A locked front-end is only usuable in mud bogs or something. I sure wouldn't want it in a street driven vehicle.

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Then out of curiousity, how do these AWD vehicles work? Are they the same setup, just different terminology?

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The awd vehicles has a sorta limited slip transfer case or something like that that will give the front end say 35% of the torque and the rear gets the other 65%. I think that's what gives them better road manners than a truck that is locked in 4wd. I'm pretty sure this is how it goes but I'm not completely positive,

larry arizona · February 19, 2005

While driving in 4WD with a limited slip rearend you are in 2x4 mode. Meaning one front and one rear. if you were slipping in mud or snow the most you will get is 3x4. one front 2 rear.

You would not be able to turn the truck if all 4 were locked.

potz1999 · February 19, 2005

I think a little extra depth here would be useful. Differentials are planetary gear sets that allow the two sides to turn at different speeds. When you turn your vehicle, the outside wheels (front and rear) must spin at higher rotational speeds since they are farther out from the turn center. Under normal traction situations in 4wd, the torque goes to all four wheels. If say the right rear tire was held stuck, mechanically speaking the differential would think the vehicle was making a right turn and allow the left rear tire to spin freely. On an open-diff 4x4, the left front and right rear thing is a most shown on a solid-axle (front and rear like K5 Blazers). Some of the torque from the driveshaft is lost by torqueing the axle: one side is lifted up a little and the other side is planted harder. The left front and right rear are the sides that lift up and lose traction, thus the differential diverts power to them (thinking that the vehicle is turning)

Limited slips and lockers try to eliminate this diversion of power. If driving a 4x4 with front and rear lockers on the street where there is good traction, the compensation for the different rotational speeds of the wheels during a turn is taken from the tires instead of the differential. Thus you lose traction (i.e. the wheel slips and makes a chirping noise)

Your truck is a good compromise between these extremes. The limited slip in the rear gives good road manners copmared to a locker but offers more traction than an open-diff. The IFS is not as prone to the axle torqueing that costs a solid axle traction. I will guess that you don't do a lot of hardcore 4wheeling, so I would stick with what you got.

I need to work on keeping my posts to under 500 words!