Anyone with a Z71 better check your gears

[fondupot]

Sticker say 3:42 Code says gu4 I would have never known about that code without this forum. It's pretty shady for gm to say 3:42 and you really have 3:08 Sent from my iPhone using Tapatalk

 

 

Even though it says 3.42 under the "standard equipment" that doesn't mean your specific truck has those gears. Standard equipment is the 4.3L V6 and 3.42 gears.

 

You have to look over on the right under wear it says "options and pricing" this will say what real gears the truck has. Technically the 5.3 motor and the 3.08 gears are optional equipment, same with 5.3 and 3.42.

 

Looks like you just read the window sticker wrong.

[redwngr]

'Standard' ratio can depend on both engine and 2wd/fwd.

 

Example. On crew cabs, 2wd v6 -std is 3.23 and 4wd it's 3.42

2wd and 4wd 5.3L - std is 3.08

2wd and 4wd 6.2L - std is 3.42

 

I wonder what ratios were in the trucks tested by those that drove both 5.3 and 6.2?

How much of the difference in 'feel' is due to ratio difference?

[SLESierra]

^{Umm, pretty easy to tell. If its slow as hell and can barely chirp the tires in first you have 3.08's, if it actually has some balls you have 3.42 or better.}

???????? Why abuse a truck if all you have to do is open the glove box and look at the build codes - besides what kind of idea is it that 3.08 is so much slower my truck has 3.42s and the truck I had while it was in the shop had 3.08s and it was not slower but it did run about 200 RPM less at 70 MPH

[Chris]

???????? Why abuse a truck if all you have to do is open the glove box and look at the build codes - besides what kind of idea is it that 3.08 is so much slower my truck has 3.42s and the truck I had while it was in the shop had 3.08s and it was not slower but it did run about 200 RPM less at 70 MPH

 

The 3.08 also has a higher THEORETICAL top speed

[pm26]

Police 2WD Tahoes are equipped with 3.08 axle gears, have lowered suspension and high speed capability tires and can run up to 145 MPH.

 

Police Crown Victorias equipped with 3.27 axle gears had slightly higher top speed than those with 3.55 axle gears. However, the 3.55 cars accelerated a bit faster.

[Chris]

As said higher theoretical top speed using the math. But even going with a Tahoe or truck you are trying to push a brick. Anything past 115 MPH is mute. It accelerates so slow past that without some sort of cam and forced induction.

[crushNchowda]

???????? Why abuse a truck if all you have to do is open the glove box and look at the build codes - besides what kind of idea is it that 3.08 is so much slower my truck has 3.42s and the truck I had while it was in the shop had 3.08s and it was not slower but it did run about 200 RPM less at 70 MPH

I can tell you it's a helluva lot slower, over 1/2 a second slower to 60mph in fact, and when you're talking about a huge truck that isn't too swift to begin with it makes a noticeable difference in daily driving. I would know- I owned a 3.08 equipped truck for 5200 miles and hated it so much I traded it on a 3.42 AT.

As said higher theoretical top speed using the math. But even going with a Tahoe or truck you are trying to push a brick. Anything past 115 MPH is mute. It accelerates so slow past that without some sort of cam and forced induction.

 

They all tap up out @ 99

[Chris]

That would be the point of "theoretical"

[Delta Tango]

Thanks guys! I just went out to my Z71 and checked the glove box sticker. GU6. I'm happy with that.

[OUSux]

Ive got 3.42s, and I recently went to 34.1" tires. Think im going to 4.10s in the rear now.......

[wandern]

Yes, he's talking about '14' model year restrictions.

 

3.73 (GT4 )is only available with max tow. (NHT)

Max tow and Z71 cannot be ordered together.

Therefore Z71 cannot have 3.73.

 

Max Trailering Package, includes 9.76" rear axle, (GT4) 3.73 rear axle ratio, (JL1) trailer brake controller, enhanced cooling radiator, revised shock tuning for increased control, heavier duty rear springs and increased RGAWR

 

Are these enhancements quantified anywhere? I haven't been able to find what the RGAWR is. Also, the heavier duty rear springs don't appear to increase the payload rating for some reason.

[White14]

Ive got 3.42s, and I recently went to 34.1" tires. Think im going to 4.10s in the rear now.......

 

Trust me go ahead and get the 4:56 gears it's way better for these trucks and you will get your gas mileage back

 

 

Sent from my iPhone using Tapatalk

[TxTruckMan]

Ive got 3.42s, and I recently went to 34.1" tires. Think im going to 4.10s in the rear now.......

Umm, you might want to consider changing the fronts as well since you have a 4x4. And since you're a tsip, I recommend 3.08 in the front for better mileage when in 4wd. ;)

 

Gig'em.

[Tim99GT]

Ive got 3.42s, and I recently went to 34.1" tires. Think im going to 4.10s in the rear now.......

 

 

Did they make that big of a difference (tires)?

[pm26]

The desired reduction in gearing in directly proportional to increase of wheel/tire diameter. For example, if you increase the tire diameter by 10%, you need to go to 10% higher gear ratio. So if you have 3.42 gears, you would need to go to 3.73 gears to maintain about the same torque at the rear wheels.