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Jerry, Master Mechanic
Category: Dodge
Satisfied Customers: 1704
Experience:  ASE Master tech, 30 years exp. troubleshooter, driveability tech
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I have a 2016 Ram Big Horn 4x4 w/5.7 Hemi engine. I have a

Customer Question

I have a 2016 Ram Big Horn 4x4 w/5.7 Hemi engine. I have a 3.21 diferential and would like to upgrade to a 3.93 diferential. I need the upgrade as I found out to late I need the bigger gear to pull the 8,500 pound travel trailer we have. My question, do we need to switch both front and back diferentials? Also, is there computer adjustments for the shift points to be right? Basically what do you think this will cost me?
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Submitted: 6 months ago.
Category: Dodge
Expert:  bill replied 6 months ago.
being a 4X4 both axles front and rear MUST be matched, so IF the 3.92 was available with a 4X4 (NOT all axle ratios are/were available with 4X4, the 4wd reduces the towing capacity) you will need to replace the gears on BOTH axles you MAY need to replace the housings as well is this a 1500,2500 OR 3500? the cost will be determined by the shop BUT it's safe to say each will be a very different price and labor to replace the gears and any other needed components PLUS programming the computer to accept the new axle ratios will be AROUND 8.0 hours EACH axle, (your essentially rebuilding the axle and new bearings and seals will be needed no matter what and being a 4X4 this must be done twice, once for each axle)
Expert:  bill replied 6 months ago.
a 1500 bighorn hemi 4x4 NO MATTER what gear ratio is only rated to 6600 pounds according to the towing guide on
Customer: replied 6 months ago.
Please take another look at the chart (attached). 6990=GVWR, the last column Max Trailer Weight Rating states 8,010 with the 3.21 differential. Besides the front and rear differential, is there anything else that needs to be modified on the truck to accommodate the higher tow rating of 10,160? Thanks!
Expert:  bill replied 6 months ago.
I need your vin to see how the truck was built, you may need a larger trans cooler and different cooling fan BUT be aware you WILL affect the warranty greatly once you change the rating and may void all warranty on the truck altogether