I am looking at an 04.5 and was wondering if anyone has swapped out the 3.73s for some 3.55s or 3.21s? A diesel is major overkill for what I plan to do with it. I tow a 8X8X12 enclosed trailer that weighs about 2500 lbs or so loaded. I do most of my driving commuting to work about 40 miles or so round trip. I want longevity, so that was the reason I chose the diesel. I'm a 25-30K per year driver. My current 4.7 quad cab suits me fine other than the fact I only get about 8 MPG pulling my draggy trailer (70+ MPH). Anyway, since I would be towing such a light load, I was wondering if I could squeeze some extra MPG by running a taller gear.

Thanks,
Kendall Ducote
www.lapowerchutes.com

 

Slowing down will help the most. I don't think there are other gears except the 3.73 and 4.11 right now for these axles.

 

It would probably be cheaper to go for a Gear Vendors or U S Gear overdrive for the truck than changing complete rearends since as was stated at present the only gears available for the American Axle are 3.73 and 4.10.

 

Several members are running the add-on OD units and are happy with them. They seem to be strong enough with a stock engine but adding more power pushes them too far.

 

have you thought about taller tires ?? Be a lot less expensive and the same effect.

 

I didn't know that there is only 2 gear ratios available for that axle. Tires seem like the only other option. Thanks for the input.

Kendall

 

I'd go with taller tires. A set of 33's will drop the ratio down on the 3.73 to like a 3.6x or 3.5x. And believe me, you don't want anything higher than that. I've got the 3.54 factory ratio and with 33's, my truck was a dog in the city. With the 35's, it's a slug.

 

If I was you, I'd buy the truck first; give it a shot with whatever its got in it, then make the business decision on whether or not to do gears.

I don't think you'd want to bother with them after you've driven it a while. You could put that cash to work elsewhere on the truck.

 

Also and it hasn't been brought up but gear swaps are really illegal.Goes against Epa and Cafe fuel mileage.Proberly will never be checked but its as serious in some ways as removing the cat.

 

Houndog, is that in GA? It not illegal to do gears here; there's a thriving market around these parts. If it was was, the local ****'s would put the kabash on it in a hearbeat.

 

That's the first I've ever heard about that.

 

Its been that way.Its a one of those things no body knows deal.Like I said I doudt it would ever be inforced.