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Choice of rear axle ratio would you pick?

coachrider

By coachrider
in Engines & Drivetrain

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Joe_K Enthusiast

Joe_K

Posted
Posted

3.08, what a joke.

Least get the 3.73's when they come available.

 

With the older transmissions they were horrible, but they do fine with the 6-speed and the new motor.

 

4L80E

1 2.48

2 1.48

3 1.00

4 0.75

 

6L80

1 4.027

2 2.364

3 1.532

4 1.152

5 0.852

6 0.667

Joe_K Enthusiast

Joe_K

Posted
Posted

Just to give a little more info...

 

The old trans with 3.73 gears gave a 9.25 final drive ratio in first gear. With 4.10 gears and the old trans the final gear ratio is 10.168. The new trans with 3.08 gears gives a final drive ratio of 12.403. Couple that with the added low end torque of the new motor and the truck moves along just fine, with a lower highway cruising rpm. Of course, if you're drag racing, putting a lift and bigger tires on it, or planning to tow 10,000lbs 3.42 or 3.73 would be better.

Badass69 Senior Enthusiast

Badass69

Posted
Posted

I laugh at this debate. Do all you that like higher gearing drive around only in first or maybe second gear? Didn't think so... So when you are a little heavy... or even empty and all you have is that 1.5 or 1.15 to one on the highway... 3.08's and 32 inch tall heavy tires. . Well leave lots of room to pass okay. Especially with all that overdrive gear and engines that need to rev... 3.73 minimum. Mechanical advantage is nice in any trans gear..thus putting the mechanical advantage in a fixed position ( the diffs) and not relying on the trans for it makes a better drive.. Toyota is about the only one that actually figured that out.

 

Joe_K Enthusiast

Joe_K

Posted
Posted

I laugh at this debate. Do all you that like higher gearing drive around only in first or maybe second gear? Didn't think so... So when you are a little heavy... or even empty and all you have is that 1.5 or 1.15 to one on the highway... 3.08's and 32 inch tall heavy tires. . Well leave lots of room to pass okay. Especially with all that overdrive gear and engines that need to rev... 3.73 minimum. Mechanical advantage is nice in any trans gear..thus putting the mechanical advantage in a fixed position ( the diffs) and not relying on the trans for it makes a better drive.. Toyota is about the only one that actually figured that out.

 

Are you serious? How is having a low cruising RPM on the highway a bad thing? If you're a little heavy or towing, tow/haul keeps the lower gears longer.

Badass69 Senior Enthusiast

Badass69

Posted
Posted

Yeah, low cruise is fine. Even with 3.73's, 32" tall tires and that .66 overdrive do that. I'm serious that I like a truck that can pull itself properly at any speed. And yes I have driven the 3.08 geared trucks... Gm just doesn't get it.

 

Joe_K Enthusiast

Joe_K

Posted
Posted

Yeah, low cruise is fine. Even with 3.73's, 32" tall tires and that .66 overdrive do that. I'm serious that I like a truck that can pull itself properly at any speed. And yes I have driven the 3.08 geared trucks... Gm just doesn't get it.

 

2014? It's a big difference.

Badass69 Senior Enthusiast

Badass69

Posted
Posted

Can't be bothered evening looking at the new trucks, sorry... and I doubt its much of a difference. A little horsepower and torque increase do little to offset lack of gearing. You still have a rev happy truck with nothing in the back. If Gm thought it was that great they wouldn't release the 373 option with the 5.3 for a lower level towing package and stayed with just 342 like the gmt900. What I want to see... the real world economy difference between 308 and 373 on the 2014... if its like anything in the past which it will be... I don't understand the want for 308.

 

Most of the world doesn't have a clue what axle ratio they have so I doubt many will care.

 

Joe_K Enthusiast

Joe_K

Posted
Posted

Can't be bothered evening looking at the new trucks, sorry... and I doubt its much of a difference. A little horsepower and torque increase do little to offset lack of gearing. You still have a rev happy truck with nothing in the back. If Gm thought it was that great they wouldn't release the 373 option with the 5.3 for a lower level towing package and stayed with just 342 like the gmt900. What I want to see... the real world economy difference between 308 and 373 on the 2014... if its like anything in the past which it will be... I don't understand the want for 308. Most of the world doesn't have a clue what axle ratio they have so I doubt many will care.

 

You doubt, but it's a huge difference. Judging by the years of the trucks in your signature they all have the old 4-speeds, where 3.08's are worthless. Like I already posted, the effective gear ratio of the 6-speeds with 3.08 gears are better than the old 4-speeds with 4.10 gears. If you plan on leaving stock size tires, and at most pulling a small boat or a utility trailer the 3.08's are perfectly fine. I barely noticed a difference when I was test driving between the 3.08's and the 3.42's. In fact, I can pass on the highway and keep it in V4 mode. If I was ordering a truck, I would go with 3.42's, but the 3.08's do just fine.

Badass69 Senior Enthusiast

Badass69

Posted
Posted
Can't be bothered evening looking at the new trucks, sorry... and I doubt its much of a difference. A little horsepower and torque increase do little to offset lack of gearing. You still have a rev happy truck with nothing in the back. If Gm thought it was that great they wouldn't release the 373 option with the 5.3 for a lower level towing package and stayed with just 342 like the gmt900. What I want to see... the real world economy difference between 308 and 373 on the 2014... if its like anything in the past which it will be... I don't understand the want for 308. Most of the world doesn't have a clue what axle ratio they have so I doubt many bywill care.

 

You doubt, but it's a huge difference. Judging by the years of the trucks in your signature they all have the old 4-speeds, where 3.08's are worthless. Like I already posted, the effective gear ratio of the 6-speeds with 3.08 gears are better than the old 4-speeds with 4.10 gears. If you plan on leaving stock size tires, and at most pulling a small boat or a utility trailer the 3.08's are perfectly fine. I barely noticed a difference when I was test driving between the 3.08's and the 3.42's. In fact, I can pass on the highway and keep it in V4 mode. If I was ordering a truck, I would go with 3.42's, but the 3.08's do just fine.

 

Sigh.... why I bother. Sure you have the same mechanical advantage as a 410 truck in first gear.... whooptee dooo. How about in 4th on the highway... nope you sure don't have the edge on 410... ever. Unless you drive around in first gear all the time you have no advantage.. and really. The 6 speed has what.. granny low and 2 overdrives. Neither are useful for anything for power when rolling. Slow enough speed you get back into second... but otherwise its 3rd and 4th like me with 2nd and 3rd.

 

308 has no business in a truck... Even 373s in my last 6 speed 09 wasn't anything wonderful. The truck would had been better off 410.

 

 

BringTheRain403 Senior Enthusiast

BringTheRain403

Posted
Posted

All I can say is that my trailblazer ss has 4.10 gears in it and the 4L60E and it passes everything but a gas station. DIC currently says 10.1 MPG. Cruising on the highway at 70 I'm turning almost 3K. I ordered 3.42's and I would have liked 3.73's. I've had both 3.73 & 3.42's in my camaro and I could honestly tell very little difference between the two. That said 3.08's are gutless gears which would probably make my 80 year old grandmother bitch about it having no balls...

 

Sent from my Galaxy Nexus using Tapatalk 2

 

Joe_K Enthusiast

Joe_K

Posted
Posted

Sigh.... why I bother. Sure you have the same mechanical advantage as a 410 truck in first gear.... whooptee dooo. How about in 4th on the highway... nope you sure don't have the edge on 410... ever. Unless you drive around in first gear all the time you have no advantage.. and really. The 6 speed has what.. granny low and 2 overdrives. Neither are useful for anything for power when rolling. Slow enough speed you get back into second... but otherwise its 3rd and 4th like me with 2nd and 3rd. 308 has no business in a truck... Even 373s in my last 6 speed 09 wasn't anything wonderful. The truck would had been better off 410.

 

Yes you'll have a mechanical advantage in OD gears, if you're not towing anything heavy or never plan on it why do you need the engine revving higher on the highway? Not everybody pulls a 10,000 lb trailer or races a 5500lb truck. If you do, wait for the NHT package or the 6.2. If you use Tow/Haul mode it drags out the gears before shifting. Trust me, this truck has no problem overtaking people on the highway, it's surprisingly quick and it zips right along in town. If you set the cruise to 65mph it gets 24-25 highway mpg.

 

All I was pointing out is I was apprehensive about buying a truck with 3.08 gears due to past experience. I drove several and the only one that had the color and options I wanted with the 5.3 had 3.08 gears. I honestly could not tell the difference between the one I bought and a Dark Maroon one I drove with 3.42's. If I was ordering a truck and had the choice, I would pick 3.42's, but the 3.08's are nothing to be afraid of if this truck is just your daily driver/family wagon. I'm sure the new motor with the very flat torque curve is what helps this truck over the old 5.3.

 

All I can say is that my trailblazer ss has 4.10 gears in it and the 4L60E and it passes everything but a gas station. DIC currently says 10.1 MPG. Cruising on the highway at 70 I'm turning almost 3K. I ordered 3.42's and I would have liked 3.73's. I've had both 3.73 & 3.42's in my camaro and I could honestly tell very little difference between the two. That said 3.08's are gutless gears which would probably make my 80 year old grandmother bitch about it having no balls... Sent from my Galaxy Nexus using Tapatalk 2

 

And someone else with an opinion that probably hasn't driven one.

kstruckcountry Senior Enthusiast

kstruckcountry

Posted
Posted

"But your mileage is likely not going to be much if any better with 3.08's, so why not get better gears?" I think that's what folks are getting at.

 

My truck, which many would consider "old", has 3.73's and a 4 speed, and still manages over 18 mpg highway. The lower gears aren't going to hurt economy that much.

Badass69 Senior Enthusiast

Badass69

Posted
Posted

In any gear beyond the first gear of the current 6 speed you have no mechanical advantage over any older truck. Like I said before.... Toyota has 430s and a 6 speed much like everyone else but without the granny first gm and ford use and a less harsh gear spread. Just because you have a deep rear gear doesn't mean the truck can't attain reasonable highway economy. That said I also don't buy 5500 lb trucks and want nothing but the best possible economy... I couldn't care any less about mileage to be truthful.

 

But if someone likes the 308s well then let them like them I guess. But when the mileage penalty no doubt will be so insignificant it will not even be measurable.. why bother.

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