3.42 swap to 4.11

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Sep 30, 2014 | 01:05 PM

#11

LQ4 Tank

Staging Lane

Joined: Sep 2014

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From: College Station, Tx.

Quote:

Originally Posted by chadjcompton

Yeah i most likely do the 4l80.. I've been researching on gears for weeks now, and from what i've been told, you will not be disappointed lol its kind of a heavy price take, especially being a 4x4, $1,200 from parts and labor for front and rear. but it'll be so worth it.. especially someone with a heavy truck like yours.. they say with 35" tires you should be running a MINIMUM of 4.11s to get you back to factory ratio basically.

Yeah I may go shorter gears, I'm not sure. Would love to have some bottom end snap and that long first gear in the 4L80 kills the launch, it doesn't really even pull hard unless I'm running 55-60 in 2nd gear and hit it.

Sep 30, 2014 | 08:06 PM

#12

slammedsam

Teching In

Joined: May 2014

Posts: 44

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From: Topeka, KS

I put 4.11's in mine about a month ago and have taken it on a few trips and have still gotten 16mpg with a 32" tall tire. Very happy with the swap!

Sep 30, 2014 | 08:16 PM

#13

GMCtrk

TECH Senior Member

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From: Dallas

Dont swap from 3.42 to 4.11 thinking you will get a gas mileage gain. I never realized a gain in city MPG. Highway MPG went from 22 to 18.

Sep 30, 2014 | 09:47 PM

#14

chadjcompton

Thread Starter

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From: Rocky Mount, NC

Yeah I definitely am not expecting a gas mileage increase. Was just curious how bad the decrease. and like I said, its not like its going to persuade my decision on getting them. I already have them, just waiting on my appointment. I know I need them cause I have heavy 20x12s and 305/50s plus I haul a 7x12 trailer with 2 mowers, a 61" cut commercial zero turn mower and 48" cut ridin mower with a 15 gallon sprayer mounted. These 4.11s are going to be glorious

Nov 4, 2014 | 07:16 AM

#15

skyhighsami

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From: Montgomery, AL

Another thing to consider if you have a 4L60E now and plan to swap to a 4L80E, the overdrive isn't as low on an 80 so you will be turning some additional RPM in OD cruising on the highway. A 4L60E is .67 OD ratio and the 4L80E is .70. Just something to consider if swapping gears now and transmissions later when you drop in a 6.0