Choice of rear axle ratio would you pick?

[robvas]

I have not towed my boat yet because I am waiting to get to 1,000 miles. It comes in at 5,100 lbs fully loaded so I am hoping it will do ok. I do not worry about Florida but we do plan on moving back to the mountains around N.C. If it does not do that well I may regear the truck. If I have read correctly it is just the gear in the rear differential and having the ECM programmed correct? I wonder if someone here has done so what the cost was and how do it do with MPG and towing performance. These trucks get good mileage anyway and I bought it to pull and not so much as a gas saver.

 

I know recently we took the boat out with a friend and used his 2013 5.7 Tundra. I was not impressed because the motor always wanted to be in the upper RPM's and would not hold a gear that well. I do not think I have ever used so much gas towing a boat. People talk about how well the Tundra tows and for the gas it burns it dang well should

Did he have 4.10 or 4.30 gears?

[robvas]

In the previous gens, the 4.10 gears were more of a necessity because a) the tranny was four speed and not six and b) the motors produced a fair amount less torque than the current gens.

Yea, people complain about the 3.08's but a 6 speed with 3.08's ends up with a much better spread of gears than the 4 speed with 4.10/4.11 gears. 4th gear in the 6 speed is somewhere between 3rd and 4th in the 4L60E and then you've got the 6th gear for the highway.

 

The 4 speed had a (steep for the time) 3.06 first gear and a huge drop to 2nd gear (1.63), the 6 speed 1st gear is 4.03 and 2nd is 2.35, 3rd gear in the 6 speed ends up being 1.53. so you have a whole nother gear in there.

[ocracokenc]

Did he have 4.10 or 4.30 gears?

He has a 4.30 gear. I was surprised because on the back roads it pulled hard but on the highway it would gear hunt between 5th and 6th. I figured with the RPM's it turns in 6th it would hold that gear on flat ground with my boat but it did not. It just burns way too much gas for me.

[ocracokenc]

Just out of curiosity. If I wanted to regear to the 3.42 what would the cost be? Would it be something my dealer could do to keep the warranty intact? Could it be done for $1,000?

[robvas]

i have heard of $500/axle I have heard of $1,000 for just the parts then another $600-$800 for the install. call around and ask

[tnchevy]

If you have 4wd you will have to change out both diffs.

[ocracokenc]

If you have 4wd you will have to change out both diffs.

I just have 2wd with the G80 locker

[majorsmackdown]

Lots of ?hit talk here but I went from a 24v lots of mods dodge diesel to the 15' gmc 1500 5.3 and i love it. Im only towing 5-6k but im not missing the diesel at all with these loads and 3.08 gearing. It works really well thus far on stock wheels/tires. 24-25 mpg hwy without trailer snd most if the time it's without trailer. It also accelerates like a sedan. Anyhow.... That's real not just calculations.

[cato]

If you have 4wd you will have to change out both diffs.

 

You will need to swap out the rear carrier. Front is fine. My truck is scheduled for a swap from 3.08 to 4.10 Yukons in 2 weeks, $1600 installed. Just a heads up. : )