Another Gear Swap Question

TDevil · Sep 1, 2015

I've been back and forth and all over the posts and can't seem to find a straight answer.
I have a 2014 1500 5.7L with 8spd transmission (8HP70) 4x4 with 3.21 gears. Looking at my window sticker, I do not have a LSD.
I have been looking into moving up to 3.92 gears both to (1) increase performance a little and (2) not lose performance if I go to slightly larger tires. I currently have P275/60R20s but possibly wanted to go to 34s if I do a leveling kit.
I have seen posts that say my rear is easy enough but the front is welded together, so I would need to find the entire front differential to do the swap. I've seen price estimates from $1500 to $3000 on here to do the swap.
If I need the front assembly, what part number / assembly am I looking for? If I go to a junkyard to look around, where / what number should I look for to indicate the truck has the 3.92 front end I would need? Is it any easier / cheaper to go to a higher ratio like 4.10s? 75% of my driving is highway, and I go off road a handful of times a year, but do travel to construction sites somewhat regularly that are essentially giant mud puddles.
Any direction is greatly appreciated.

WadXpress · Sep 1, 2015

You need a 2011 earlier hub to hub front diff assembly and you will put 3.92s or 4.10s into that. You don't look for one with 3.92s I think they came with 3.55s

Hemi_Express2013 · Sep 1, 2015

If you're staying with stock ratio's (3.92), you just need the front differential assembly. Mopar at one time, sold just the inner assembly for around $750. They may still do that with your year. More than likely you will have to have your dealer "service" the front as it's been called. If not, the housing with no inners is $1200. If you want to go higher in ratio from 3.92, then you will need a 2006-2011 front carrier. From there, there is a few options on install. "You need to remove the front housing and literally throw it away.
Take the comp flange off it and machine it to the measurements of the 2006 thru 20011 front end yoke, then put the comp flange back on the aam front diff.
Install that and modify the 2010 thru 2015 bracket at the back". I think you can just by the front driveshaft and install without machining I got my whole assembly off of eBay for $284.00+75.00 shipping. Came with comp flange and a driveshaft. Doesn't matter what gear ratio it comes with.
The rear has a few options also. I have just now got all my parts for the install. There are a few guys that have made the swap. Some say you also need the older style cv axles. I'm pretty sure greychevy didn't replace his on '12, but that doesn't mean we wont,'13-'15.

I really wish RF would make this swap a sticky!

bigolayne · Sep 1, 2015

I'm in the same boat. Really want to jump to the 3.92's as well. I have a 2015 and have done the exhaust, level with the bills, vararam and catch. Looking at the cam/head swap, supercharger or even the twin turbos

TDevil · Sep 2, 2015

Thanks everyone. That helps a lot.
I'm very happy with the performance right now, but I've also driven a friends Tundra which has something like 3.92 and the torque was impressive. I'd love to not lose the level I am at now if I get slightly larger tires. Guess I'll have to start saving my pennies!

Another Gear Swap Question

TDevil

Member

WadXpress

Senior Member

Hemi_Express2013

Senior Member

bigolayne

Senior Member

TDevil

Member

Similar threads

Latest posts

Staff online

Members online

Forum statistics

Share this page