Loud while Towing

[Jeff_]

Flip your pill in the trans if you haven’t already.
I did a long tow of 3000+ miles pulling 6000lbs all throughout the PNW (think mountains and grades) and it stayed cool the whole time. Which helps it shift and just drive smoother.

And as long as you give it easy throttle inputs and brake applications (and the load is balanced correctly) you shouldn’t even notice it back there.

 

[Doubeleive]

Would going from 3.42 to 3.73 really make all that much difference?

my 03 had a noticeable difference with 3.73, when I first got it I didn't even know it had 3.73's I just thought it was touchy, that thing would do a burn out at the drop of a hat

 

[alpha_omega]

What of all is required to do the swap for a 3.73 in these newer SUV’s? Is it much different than the 3.08 to a 3.42 swap?

 

[swathdiver]

Would going from 3.42 to 3.73 really make all that much difference?

Towing wise, GM added a 1,000 pounds or so to the towing capacity by switching to 3.73s from 3.42s. The Sierra launches hard even on 35s, they ran mid 14s stock.

swathdiver, would you recommend swap the pill for his tranny...

Absolutely! Heat is a transmissions worst enemy.

 

[swathdiver]

Would going from 3.42 to 3.73 really make all that much difference?

Chris, here is a Torque at Differential and Force in Newtons calculator I've been playing with to see how much power makes it to the wheels. The first two will be my truck with 3.42 and 3.73 gears and the third is my daughter's NHT Sierra. The Horsepower and Torque engine data came from those Tech-2 runs we did recently and then graphed them out. Both trucks were on gasoline a the time and mine is a little down on power because of those leaky intake gaskets.

Anyhow, here it is, and what do you all think? Is it a big difference towing wise to change to 3.73s and make it worth the extra 158 rpms?






When I was playing with this, the little 5.3 would need 4.30 gears to equal the towing prowess of the L96 6.0 motor used in the 2500s. The L96 would need 4.10s to even get close to the 6.2s towing abilities.

 

[SteveoTahoe]

What RPM is it turning? It might actually be in the correct gear for the load and speed. Maybe that load and speed just so happens to be where the intake resonance is loudest. The Volant, with not having resonator chambers, won't attenuate the intake growl like the factory intake did.

I do think the volant is just plain loud. Even with no trailer it is super loud even at half throttle during acceleration. Very disappointed in this upgrade.

I don’t recall what RPM but I think it was around 2300 or 2500, is always right on the cusp of a shift. Once it shifted, it was quiet, but it constantly was shifting down because I couldn’t maintain speeds, even at 60-65 it does this.

 

[SteveoTahoe]

swathdiver, would you recommend swap the pill for his tranny, seems like it is under a lot of pressure and possibly a lot of heat. I like your suggestion about slowing down a bit to find that sweet spot without all the drones and groans.

What does swap the pill mean? Sorry for my ignorance

 

[iamdub]

Towing wise, GM added a 1,000 pounds or so to the towing capacity by switching to 3.73s from 3.42s.

Nice! I didn't think it'd be that much of a difference. I just did the simple math: Considering the difference from 3.08 to 3.42, 3.73 is almost doubling that gain.

 

[iamdub]

Chris, here is a Torque at Differential and Force in Newtons calculator I've been playing with to see how much power makes it to the wheels. The first two will be my truck with 3.42 and 3.73 gears and the third is my daughter's NHT Sierra. The Horsepower and Torque engine data came from those Tech-2 runs we did recently and then graphed them out. Both trucks were on gasoline a the time and mine is a little down on power because of those leaky intake gaskets.

Anyhow, here it is, and what do you all think? Is it a big difference towing wise to change to 3.73s and make it worth the extra 158 rpms?

View attachment 360840
View attachment 360841

View attachment 360842

When I was playing with this, the little 5.3 would need 4.30 gears to equal the towing prowess of the L96 6.0 motor used in the 2500s. The L96 would need 4.10s to even get close to the 6.2s towing abilities.

With your Yukon, if I'm understanding correctly and looking at 4000 RPM (where the peaks are), I'm coming up with a 20 ft. lbs. gain at the wheels. This doesn't seem massive considering the expense of swapping gears. But, it's gains all across the board and helpful to the trans. I'd have to say it's a win.

 

[Tahoe14]

SteveoTahoe, Look down about 4 posts from this one titled "Updated Thermal Control Valve". Its a valve in the tranny that lowers the temperature. You can replace with an updated part or flip it upside down.