Ox Locker in GMT900 with 3.42 gears?

[swathdiver]

Most 4-speed trucks set up for max towing come with 3.73s. If yours was a lighter duty optioned model, it would have 3.42s and or 3.23s depending on the engine. A 4.10 upgrade is quite common.

Below are three examples of the gear multiplication and RPMs at speed for a given gear with new stock sized tires:







See the torque multiplication with each gear change for each gear in the transmission? How many rpms do you want to be turning on the highway?

This comment is directed to everyone:

When talking gear swaps, it's important to establish what kind of transmission we're dealing with. A 4.10 gear set is not necessarily the best thing for a 3-speed or 10-speed transmission for example. Lower numeric ratios would deliver better overall performance. Another way to look at it is that 4.10s behind a 4-speed don't come close to equaling the performance of 3.42s behind a 6-speed.

 

[07CLASSIC]

Most 4-speed trucks set up for max towing come with 3.73s. If yours was a lighter duty optioned model, it would have 3.42s and or 3.23s depending on the engine. A 4.10 upgrade is quite common.

Below are three examples of the gear multiplication and RPMs at speed for a given gear with new stock sized tires:

View attachment 451333

View attachment 451334

View attachment 451335

See the torque multiplication with each gear change for each gear in the transmission? How many rpms do you want to be turning on the highway?

This comment is directed to everyone:

When talking gear swaps, it's important to establish what kind of transmission we're dealing with. A 4.10 gear set is not necessarily the best thing for a 3-speed or 10-speed transmission for example. Lower numeric ratios would deliver better overall performance. Another way to look at it is that 4.10s behind a 4-speed don't come close to equaling the performance of 3.42s behind a 6-speed.

Very useful. Thanks, SD.

 

[07CLASSIC]

can't find my invoice for mine, had 4wheel parts install it. I will probably go by there in a couple more days and see if they will print me out a new invoice.

Thanks D. Hope you were headed by there anyway.

 

[Doubeleive]

Thanks D. Hope you were headed by there anyway.

I am gotta get a quote and make a appointment for a alignment

 

[swathdiver]

Yeah, that's what I'm most interested in. Better pull on hills around town and better towing torque.

4.30 gears!

 

[07CLASSIC]

4.30 gears!

You're doing that on purpose, right?

Now I've gotta look into another possible option. And, to be honest, I don't do much highway at all these days so I could logically make a case for 4.10/4.30.

There's a possibility I could be towing on highways more in future though, but .... what if I'm not?

Thanks for that.

 

[07CLASSIC]

I am gotta get a quote and make a appointment for a alignment

Hey you didn't regear when you got your TrueTrac, did you? If so, gimme the price of the parts and labor when you get your invoice. Just for a reference. I know everybody charges differently.

 

[Doubeleive]

Hey you didn't regear when you got your TrueTrac, did you? If so, gimme the price of the parts and labor when you get your invoice. Just for a reference. I know everybody charges differently.

no but i believe it required (or I requested) a new pinion set regardless, I purchased a new yoke separate from the dealer
mine is 3.42 already. the one I need to change now is in the Silverado, finding a gu6 front diff should be no problem, the issue it is has the 9.5" rear end, not even sure if they make a truetrac in the 9.5. in any case need to pay down some debt first before I open that can of worms. could not find a 3.42 silverado when I was shopping for it with the options I wanted anyway. one Sierra denali showed up on a lot with everything I wanted, called the dealer late in the day and they didn't even have it priced yet, called the next morning and they said they sent it to auction

 

[07CLASSIC]

Ouch.

I don't know all the figures for your diff and axles, etc., but this looks like it might be the model you'd need.

14 bolt?

914A538
https://www.eaton.com/us/en-us/skuPage.914A538.html

 

[strutaeng]

I daily drive an 06 Suburban LQ4/4L80e/4.10. We also own a 2020 Express 3500 passenger van with the L96/6L90/3.42. My wife drives the van daily to pick/drop off the kids at school. I think both vehicles are close in curb weight

I sometimes get to drive the van and I actually prefer the 4L80/4.10 combination.

The van will tend to downshift too often when I try to accelerate. The cruising speed is too low, like 1600 RPM. Once it's in the 2200-2400 RPM, then it comes alive.

The suburban cruises at higher RPM of course (2400 RPM), but it does so where the engine
is in the higher power band. That one will just go when I push the accelerator. Very rare to downshift.