Upgrading Gears 3.73 to 4.10

Many of the comments come from pre 6 speed transmission thinking. Depending on speeds and terrain, you might actually increase MPG along with towing better. I have a 2011 GMC 2500HD 4WD CCSB 6.0/6sp with 3.73 gears. I wish I had got the 4.10 (and my brother did).

At a comfortable towing speed, my truck wants a bit more power and shifts down, it has plenty so it shifts up. I can limit it to the lower gear, but really don't need the rpms that high. With 4.10 gears, the rpms would be 200-300 higher and the truck would have enough power then to not be shifting down. Often in this scenario, the 4.10 gears provide better MPG.

The truck will likely get better mileage in town also since with 4.10 gears it will start out easier.

I do fine, just kick myself for not getting 4.10 since I ordered my truck.

You will likely tow fine with 3.73, but if not, you could have it changed later. I don't see it as deal breaker for the new 5th wheel.

This is a hot topic over on ram forum. Some trucks come with 3.73s like mine, some can be had with 4.10s.

I'm sure the 4.10s are better for pulling, and the 4.10 geared trucks have a 3000 lb higher tow rating.

However, i just don't think it's a big enough difference to worry about, unlesd8 your towing heavy all the time. My Layton is 6k gvwr and the campers we're looking at are in the 7- 7500 gvwr range, so well within the capability of my truck

If your going to go through the expense of changing gears, go straight to 4.30s to make a noticeable improvement over your 3.73s, which is already a fairly steep gear, just my .02

After having everything from 3.08 to 4.56 with stock size tires in various pickups over the years, I like the 3.73 better than any of them. Plenty of gear reduction for launches and a reasonable rpm for cruising both towing and empty. On the uphills at interstate speeds, 2nd gear is between 3800 and 4500rpm depending on speed. I'd leave it as is. The higher tow rating with the 4.10 has to do with startability up a grade. All else is just a downshift away.

I pull similar wieght and have 3:73 gear set in mine and don't have any issues. My fifth wheel is mid profile. If you were pulling a high profile fifth wheel, that is a lot taller in the front then you may notice more drag for sure. I don't think you need to swap out gears so much to a 4:10 just yet. Try it first and see how it does. The biggest workload on the engine is from wind drag. I tow in Florida in 5th gear OD, hills will put me in 4th in Florida and South Georgia. North Georgia I leave it in 4th and will drop to 3rd on steep inclines if needed. I originally wanted a 4:10 ratio but am happy with the 3:73. I don't camp but a few times a year so a gear swap is not an important upgrade for me. I think that if your towing a lot all the time then a 4:10 or even 4:30 gear set would be the best overall. My thoughts though is to try it for a while and decide after, but if it's a mid profile you should have no issues.

What a gear ratio does is cause the engine to turn at a higher RPM at any given speed. More RPM equates to more Horsepower being transmitted to the wheels, at least up to the peak RPM in the HP curve.

Yes, it is true that the engine's capacity to produce power is not changed.

The engine will run about 300RPM faster at highway speed going from 3.73 to 4.10.

If you are happy with how it tows now, I agree with the others, 500lbs will not make a noticeable difference. HOWEVER, if the new trailer has significantly more frontal area than the old trailer, you may still need the gear change. Most of your power needs come from wind drag.

dodge guy wrote:
Your towing mileage should go up approx. .5mpg. Your unloaded hwy will go down. However I wouldn't do a 3.73-4.10 swap. I would go to 4.30 or similar available ratio!

With that said I would tow it as is and see how it does and then decide! I went from 3.73-4.30 and it was a noticeable improvement.

Agree!!

Try it first. But I had a 2011 F250 6.2 gas with 373. Swapped the gears out for 430. Lifted with 35" tires the gear change equaled out about 410. That put a big smile on my face!! Empty MPG stayed the same but towing MPG improved!!

My 2016 F250 6.7 diesel has 330. Now lifted with 35" tires it equals out to about a 300. Not as impressive power and I took a 2 MPG hit!!! Later this Spring I will swap out the 330 for my 373 saved from the '11 gasser. That should put me around 355 which will get my power and MPG back!! :)

Your towing mileage should go up approx. .5mpg. Your unloaded hwy will go down. However I wouldn't do a 3.73-4.10 swap. I would go to 4.30 or similar available ratio!

With that said I would tow it as is and see how it does and then decide! I went from 3.73-4.30 and it was a noticeable improvement.

Thanks

If your pulling heavy all the time a higher ratio rear end makes sense otherwise when you need more power drop a gear or two or three. You don't have to use 5th or 6th gear just because they are there.

I've had three dualies with 410s and I love those gears for a work truck but they arent much good for unloaded Highway cruisers. Those low gears make the truck do everything easier Craig