I Would Like To Know If Anyone Pulls With 3:73 Gearing / Manual. Does The Truck Pull Well In 6th Gear And Hold Speed. Test Case Of 12,000 Lbs. What Is The Norm For This Gear Ratio?

 

Your gonna get various answers but the 3.73 guys will say OH YEA no problem.Just use 5th if needed.They make 4.10s for a reason.I pull 11k or so with my truck.Thats enough of a reason for me.

 

What Speed Does 5th Give 3:73? What Speed Does 3:73 Have In 6th At 1900 Rpm?

 

It will probably pull 12K in 6th no problem on flat ground or even up a slight grade. It would probably be best to drop to 5th for anything more. Speeds for 3.73/direct stock tires: 45=1900, 50= 2100, 55=2300, 60=2500, 65=2700, 70=3000. I'm going to guess and say a G56 will give you about 62 MPH at 1900.

Nick

 

It is true that they make 4.10's for a reason but you must weigh in just how much of the trucks life will be spent towing. If you're going to be towing constantly then 4.10's are great. But if you tow once every month or less maybe you can live with 3.73's. The G56's are known for having a pretty low OD anyway. I always feel like I need another gear above OD or higher gears. I'd say I would be satisfied with 3.54's or 3.42's.

A buddy of mine had a 00 Chevy 3500 dually with an NV4500 and a 454. It was an awesome truck but had 4.56 gears. It would pull really well but he only towed with it a few times a year. Fuel mileage certainly suffered. He constantly got about 7~8 mpg towing and it only improved to about 11 unloaded. Another guy we knew had a similar truck, the only big difference was his had 3.73's and he got around 16 mpg.

 

I didn't think you could get 4:10 with a man. from the factory

 

You can't.Not with a G56 trans

 

Bad guess. My g56 sits at about 2200 at 60 mph.

 

Pulling 40,000 with 22.5's in 6th gear is no problum in the flats and small grades. I run around 2100 at 75mph.

 

They also don't offer the G56 trans with 4.10 gears for a reason.

 

Because in essense its geared like a nv5600 with 4.10s.That was changed somewhat on 07 5.9s. I wish my truck has a lower 1st and reverse.It needs to crawl slow in those two gears with a big trailer hooked.

 

My last truck was NV5600 with 3.73's and my 5th wheel weighs a little under 12k...

Yes, on the freeway it will pull 6th just fine, turning around 2100 at a bit over 65.

If I get below 55 say on a narrow 2 lane winding mountain road, I'd be in 5th to avoid lugging the motor below 1600 rpm. I also drop to 5th on the blue mountain pass (like 6% grade for miles, with 50 mph curves).

Oddly, I've noticed the thing will get better mileage at just under 55 in 5th than it does at around 60 in 6th, so I think RPM doesn't have as much an effect on MPG as people think. At least in my experience, road speed has a huge effect, and RPM doesn't.

A few times manuvering the trailer between trees someplace steep, I've felt the need to use low range.

Current truck has the G and 3.73 and turns a couple hundred RPM higher on the freeway. Haven't towed with it yet, but I'm sure it will pull like a beast.


Bottom line, if you are talking about the NV5600 and live in steep mountains and will either be constantly towing 12k, or plan to tow up around 18k, the 4.10's might be worht having. Otherwise, I'd go 3.73.

 

my 04.5 has 3.73s with stock size tires....i routenly pull 20-40k with it and do not have a problem...but i drive 55-65 EVERYWHERE when im pulling those trailers and do use 5th almost all the time, not due to lack of power, but to keep the egts down and i most definently get better mpgs running at 2400 than i do at 1700 under those loads....i would not mind having 410's in this truck because all it does is work....my 06 has the G56 and never sees more than a light trailer...with 295's i think the gearing is still a little low but i cruise that truck more around 75-80....i wish i could swap the trannies!!!

 

In 6th with 3.73's?

Nick

 

yea the early g56 had a lower overdrive then the later ones could tell the differ in my 07 when they replaced it in april 07. i constantly haul loads with my trucks its why i own them and i will never have a 4:10 again the 3:73 do great and they get better mileage. an older g56 is like a nv5600 with 4:10. i run out in west texas and new mexico a lot and can run just as fast as i want with my 3:73's