3.21 to 3.92

bryan28 · Mar 28, 2017

I have 3.21 in my '14 Sport but am thinking of going to the 3.92 and putting a lift and 35s on it. It is 4wd. Talked to service manager at a local dealer and he quoted $262 for rear parts and $1493 for parts on front diff. My question is would i need to have the speedo recalibrated if all i did for now was change the diffs? Or could that wait until the bigger tires were installed?

matt.davidson09 · Mar 28, 2017

Following as I eventually want to do the same with 37s. $262 seems cheap for regearing the rear?

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shane1981 · Mar 28, 2017

you wont need it calibrated just for the gears. the speed sensors are behind the rotor so they read wheel speed

tuned by Jay Greene

bryan28 · Mar 28, 2017

Well i just heard back from them and they said it'd be a low estimate of $3900 for everything installed but that they're not sure it'd work up front. Something about the transfer case being designed to work with what originally came in the truck (3.21s). And that it may be a couple more grand if they had to do something to make it work. I know nothing about this stuff but i'm calling bs! But since they seem incompetent i will not be letting them do it.

Sickem · Mar 28, 2017

Lol. That's ridiculous and don't even make sense that the transfer case would be impacted by going to lower gears.

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69GWC · Mar 28, 2017

It wont be, seems real high to me, search on here someone did this not to long ago and the parts were less then you would think.

Pull Ya · Mar 28, 2017

I think that Moe's Performance(a vendor on this site)has the parts you need. I believe his prices are much cheaper than a dealer.
Jay

Trexterra · Mar 29, 2017

That's about the price 4wheelparts did mine for in my 14. Dealer paid 3200 and I only paid 800 though.

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RLJ10X · Mar 29, 2017

35"/3.92/8 speed would probably be ok. I don' know whitch trammy you uys have......

If it was me, and l was going with 37 inch tires, l would research 4.10s real hard. Maybe even 4.56s. Talk to Matt at Moe's. He will steer you in the right direction.

I have 32"/33" stockish tires with 4.10s, and the 545RFE, just a CAI, and a tune. My truck moves out very well for a nearly stock, 5600 pound truck.

SilverStreak88 · Mar 29, 2017

4.10's or higher, you'll be happier.

bryan28 · Mar 29, 2017

Well my local dealer who I bought the truck from won't even touch that job. They also said it would void the warranty. It's a 14 so has 12 months left on the 3 yr bumper-bumper and 3 years left of the 5yr/100k mile powertrain warranty. So I'm either gonna hold on to what I have or buy a new one equipped the way I want.

crash68 · Mar 29, 2017

bryan28 said:
Well my local dealer who I bought the truck from won't even touch that job. They also said it would void the warranty. It's a 14 so has 12 months left on the 3 yr bumper-bumper and 3 years left of the 5yr/100k mile powertrain warranty.

That dealer is so full of crap they would plug a toilet.
Sounds more like they don't have any techs skilled enough to do the swap.
Find another dealer or a good drive train shop. Only thing could "voided" on the warranty would be the axles and how often do they go bad.

fasthemiram12 · Mar 29, 2017

You can't just put gears in your front housing... you have to swap to a 3.92 front ifs assembly. They are not serviceable 2012+

jonathanhudaon · Mar 29, 2017

There's got to be some way around this. I want to change the gear in my 13 but have stayed away because of the cost associated with a full front swap. Someone must know another that's not so costly

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Trexterra · Mar 30, 2017

jonathanhudaon said:
There's got to be some way around this. I want to change the gear in my 13 but have stayed away because of the cost associated with a full front swap. Someone must know another that's not so costly

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You could try and find a used stock 3.92 front end and matching rear. That's the only current "cheap" method. Iirc 4.10s weren't even an option due to the front diff. I could be wrong though.

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69GWC · Mar 30, 2017

The front diff is not that much money a guy posted what it cost a month ago or so.
swap out the front diff and change the gears in the rear.

3.21 to 3.92

bryan28

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matt.davidson09

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shane1981

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Sickem

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Pull Ya

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