3.08 Rear End

[STRIKE ONE]

Folks I have to admit I have screwed up. Bought a new Tahoe intending to tow our 18.5 ft. fish-n-ski but after looking at multiple vehicles trying to find the best option package to suit our needs I wound up buying one with the 3.08 axle thinking it had the towing package with the 3.42.

I still can't believe I did something so stupid as this but we now have the vehicle and I can't afford the loss involved in trading for another. Other than just venting my frustration with my own stupidity, I guess I am seeking reasurrance that this will still get the job done even without the towing package and the higher ratio rear end. Average tow will be less than 75 miles with mostly rolling terrain with few hills. Total weight should be around (I believe) about 4000 lbs. with listed capacity as 5400 lbs. What say you???

Any and all comments will be appreciated, except those directed at my stupidity. I have already beat myself up over that

 

[ClassyGlassy]

Re: 3.08 Rear End

trick will be on the take off.........you will need to take off and accelerate slower than everyone else around you and not push it too hard!! Make your highway top speed 60mph and just leave a little earlier to get somewhere with it and leave extra room to slow to a stop with pumping of the brakes more often rather than holding it down to the floor. Tow in Drive instead of Overdrive as the transmission will shift less often and will be a more solid shift! You're fine if you follow these basic rules.........

If you decide to keep up with traffic and horse it too much, YOU WILL have problems!!

 

[Yellow Yota]

Re: 3.08 Rear End

I would change the axle gear ratios. I assume other ratios are available other than the two listed above. I'd like to see a 3.73 or so. Then you would walk away from the others that think an intake and exhaust along with a chip is the right way to make up for the power loss associated with larger tires.

Oh yeah. I'd put it on slightly larger tires as well.


Other than that, just use a lower gear in the transmission. Like stated above, tow in Drive. If it's a 6 speed tranny, lose 6th gear.

 

[Floatsum]

Re: 3.08 Rear End

Brand new vehicle?
I'd conside new ring and pinion setup. Maybe add a no slip diff. while at it.
Finding someone to do it could be a issue though. Really needs to be done right,, not botched.

 

[Titanium48]

Re: 3.08 Rear End

I wouldn't worry about it if you have the 6-speed transmission. It has an extra-low 4:1 1st gear ratio for lots of get-going torque at the wheels and close-ratio middle gears so there won't be any "flat spots" where your engine is lugging in a higher gear but you're going to fast to shift to a lower gear. Just consider it a 5 speed when towing.

 

[dockwrecker]

Re: 3.08 Rear End

You'll be OK with the 6 speed, but don't expect it to ever hit 6th gear. Maybe, but not for long. Talk to Chevy whether it needs a trans cooler, and get their factory trailer wiring harness to keep your check engine light from going off when your trailer is hooked up. (they seem to be sensitive about this) Overall, bet you're just fine.

 

[oldjeep]

Re: 3.08 Rear End

3.08 will be fine for towing 3500lbs -4000lbs (which should be way more than your boat actually weighs), a minivan can pull that much with ease.

My Ram has 3.21 gears and tows it's 6K capacity with no issues at all. As long as you are not intending on towing something a lot heavier than an 18ft boat then relax and enjoy the gas milage that you get when you are not towing.

 

[Bob_VT]

Re: 3.08 Rear End

You are fine.

Do not tow in overdrive.

You are towing a fish and ski boat....... not a tug boat

 

[Mischief Managed]

Re: 3.08 Rear End

You are towing 4000 lbs with a truck rated for 5400. There's no problem. Go have fun with your boat.

 

[TilliamWe]

Re: 3.08 Rear End

You are towing 4000 lbs with a truck rated for 5400. There's no problem. Go have fun with your boat.

Exactly

 

[45Auto]

Re: 3.08 Rear End

If it was mine I would put an auxialiary transmission cooler on it if it doesn't already have one. Other than that, as others have said, don't worry about it. You'll never know the difference.

 

[Silvertip]

Re: 3.08 Rear End

Are you sure you have 3.08 gears or a 3.08 final drive ratio. These are two completely different numbers. 3.08 is the differential gear ratio and has nothing to do with overdrive. It is a fixed ratio. Final drive ratio is the top gear ratio which does include overdrive. So the truck may have 3.73 gears but in overdrive (say 20% reduction) that puts you in the 3.08 category or the engine turns 3.08 times to make the wheels turn once. In direct (1:1) the engine turns 3.73 times to make the wheels turn once. So in effect you just misunderstood what you read. In direct drive (no overdrive the engine and drive shaft rotate at the same speed. In overdrive the engine runs slower than the driveshaft -- hence the term overdrive. Beside, I don't the truck is even available with 3.08 gears. But then I've been wrong before --- once I think!

 

[oldjeep]

Re: 3.08 Rear End

3.08 would be a normal chevy gear ratio and is what would be shown on the window sticker.

 

[captkevin]

Re: 3.08 Rear End

Chevy seems to really like the 3.08 gears these days. Was looking a new Silverado's & could not find one that didn't have the 3.08. Doesn't make any sense.

 

[Silvertip]

Re: 3.08 Rear End

That puts the final drive into the 2.40 range. Got to be a complete slug. But with the government pushing for better fuel economy, one way to get it (falsely) is to play with rear end gears. Only problem is runing into a wind, hilly terrain, or when towing fuel economy goes down the drain. As a result the tranny takes the beating because it is shifting all the time. Lots of stories about these "busy transmissions".

 

[TilliamWe]

Re: 3.08 Rear End

Chevy seems to really like the 3.08 gears these days. Was looking a new Silverado's & could not find one that didn't have the 3.08. Doesn't make any sense.

Sure it does. Witht he SIX speed auto, 1st gear is very LOW. No need for 3.73s like there was with the old FOUR speed auto.

If you didn't save the window sticker, look inside the glove box for the label with all the option codes. Go to the Gs. GU4 should be 3.08, GU5 is 3.23, GU6 is 3.42, GT4 is 3.73 and GT5 is 4.10. Hope that helps.

 

[oldjeep]

Re: 3.08 Rear End

Sluggish - not neccessarily. The thing to remember is that while some of these trucks have lower (numerically) gear ratios, then engines are a bit better than what we used to have. While my Ram has 3.21 gears, it also has 390HP and 400ft lbs of torque. Compared to some older pickups I've had with 4:10 gears, this one tows better.

The gear ratio does allow a truck with that much power to get an honest 21 MPG on the highway (unloaded)

 

[45Auto]

Re: 3.08 Rear End

Are you sure you have 3.08 gears or a 3.08 final drive ratio. These are two completely different numbers. 3.08 is the differential gear ratio and has nothing to do with overdrive. It is a fixed ratio. Final drive ratio is the top gear ratio which does include overdrive.

You are confused on your terminology. You're mixing up FINAL DRAIVE RATIO with OVERALL DRIVE RATIO. Final drive ratio is the gear reduction in the rear end. What you are describing including the transmission ratio is the OVERALL DRIVE RATIO.

Maybe these links will help clarify it for you.

Final Drive Ratio:

http://www.newcarbuyingguide.com/index.php/news/main/771/event=view

This one has a description of final vs overall drive ratio in the last couple of paragraphs:

http://www.gears-manufacturers.com/gear-ratios.html

 

[Silvertip]

Re: 3.08 Rear End

I suppose this is another of those threads that could go on forever but my point about such high gearing is that while deep first and even second gears is essential to get you moving, once moving, that axle ratio is just as important to maintain high engine vacuum which translates directly to economy. Using your 3.21 vs a 3.08 gear as an example. That represents a fairly significant difference in power delivery to the rear wheels. Newer vehicles also tend to run much larger tires than trucks did in the past so that is another factor that alters effective axle ratio. HP, axle ratio, terrain and truck useage all must play together in order to optimize the balance between performance and fuel economy. This boils down to how much towing one does and the terrain where one must use the vehicle the most. If you live in Kansas or Nebraska for example, 3.08 gears in truck that doesn't tow anything might work fine and get great fuel economy. Hook up a horse trailer or similar and you would beg for deeper gears. Even strong headwinds affect performance and it is magnified by high gearing. One of the most annoying trips I ever made was driving my brothers Toyota Highlander to Colorado. On even the slightest grades the tranny would not stay put and even my wife commented if something was wrong with this vehicle. I had to drive less than the 75 MPH posted speed in Nebraska because this vehicle would not stay in top gear and it reved like nuts out of OD. Needless to say this vehicle is not an economy champ either. Big difference in vehicles to be sure but the concepts still apply. No vehicle I've ever owned behaved so poorly.

 

[ClassyGlassy]

Re: 3.08 Rear End

I can't believe this has gotten so OFF topic! The original person to start this thread has 1 post.......1 POST!!!! He hasn't responded to this 1 post yet. Barely anyone has even answered his original question. Too many times I read someone's "advice" or supposed knowledge on a subject and they rant and rave for 2 minutes as if they're trying to prove something............

GET REAL!!!