Gear question

Remmag · February 8, 2014

If you have a 308 rear end and in the future wanted to change to 342

Other than changing the gears what would be required

Such as speedometer , programming etc

Carder09 · February 8, 2014

Go at least 3.73.

white1500 · February 8, 2014

+1 go at least to a 3.73.

And what's your reasoning behind changing gears?

OUSux · February 8, 2014

Go at least 3.73.

at a minimum, i say 4.10s

kstruckcountry · February 8, 2014

I'm very happy with 3.73's... I can get 18 highway and the pulling power is there, not bad mileage for a 2006. I pulled almost 10k this summer and it wasn't a problem. You'll need to recalibrate with a programmer... Easy to do yourself. Or get a good tune and they'll do it for you.

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thewhitestallion · February 8, 2014

agreed. if your going to go through all the trouble to replace the gears, go at least 3.73...

Sooperdave · February 8, 2014

+another on the 3.73's. Heavy truck with a mid to upper powerband and good overdrive from the 6spd trans... No reason not to. Basically adjusting parameters in the computer tuning to correct for the speedo.

Remmag · February 8, 2014

Thanks for the tips

I am not sure if I am changing gears

Mine is a 308 and haven't towed with it yet, don't think I will push the max rating on it

Just wanted to know about the option should I want to change

I know I had a chevelle and had a couple different gear sets in it and It wasn't a real big deal

2017HD · February 9, 2014

While I agree that going from a 3.08 to a 3.42 is minor change and that going to 3.73 would be better. It has been awhile since I changed rear end gears, but I believe that going from 3.08 to 3.43 involves only the pinion gear change. When I went from a 3.08 to 3.73 it required both a ring and pinion gear change. It might also require a housing change. You also need to plan on changing the three bearings involved.

Sooperdave · February 10, 2014

While I agree that going from a 3.08 to a 3.42 is minor change and that going to 3.73 would be better. It has been awhile since I changed rear end gears, but I believe that going from 3.08 to 3.43 involves only the pinion gear change. When I went from a 3.08 to 3.73 it required both a ring and pinion gear change. It might also require a housing change. You also need to plan on changing the three bearings involved.

It requires both the ring and pinion. You should be able to find a gearset to match the carrier as well. Prolly be a 3 series if GM still uses different carriers based on ratio. Being the application is practically new, I wouldn't worry about bearings. Should be an easy swap for a good installer. But finding a good installer is key. If not properly setup, they will be noisy.

OUSux · February 10, 2014

I went to have my rears replaced and he said then I have to do the front ones too, and truth to that?

KMGMC · February 10, 2014

Ya there's a lot of truth to that, you can't switch the rears and not get the fronts done as well. The front and back have to have the same gear ratio.

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OUSux · February 10, 2014

What prices are yall seeing for doing the front and rear gears?

fondupot · February 10, 2014

What prices are yall seeing for doing the front and rear gears?

Expect to drop at least 2 grand on parts and labor for a front and rear differential gear swap. The rear is easy because they can just open up the pumpkin and swap the gears relatively easy.

the front diff however has to be totally removed from the truck and the swap is done on a workbench. It cant be done on the vehicle, so it takes more time, thus adding more cost.

kstruckcountry · February 10, 2014

If the k2 are anything like past gens, dropping the front axle takes no more more than 30 minutes. The figure I've seen thrown around is $2000 for both axles.