2021 Gladiator Rubicon re-gear to 4.88s?

[Dls79]

I have a 2021 Gladiator Rubicon that I’m running Nitto Ridge Grapplers (315x70Rx17) a Smartcap with roof rack with a cargo box and 270 awning. I also daily carry a lot of weight in the bed. I also occasionally pull a small trailer. I rarely see 8th gear although I do about 15% interstate driving and about 20% medium intensity offroad driving.. the remaining use is local rural county road (rough gravel often). I currently average 13.4 mpg with my auto transmission and 3.6 Pentastar.I believe that I would benefit from deeper gearing. My local dealer is trying to discourage re-gearing and even had told me that because my truck has factory 210 front Dana 44 front axle (220 rear) the 4.88 gearing will not physically fit in the front pumpkin. What dos the forum say?

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[Bacstar]

i ran 4.88's on mine and still do on 35" soon to be 37" tires. wouldn't trust the dealer to regear, find you a local offroad shop and get some honest reviews before committing to any work. You''ll also need something like a Taser to program the speedo and gear ratio.

I off road and tow a 3200# travel trailer. While towing i'll get 8-13 mpg depending on terrain, 16mpg normally.

 

[Dls79]

I completely understand about allowing the dealership do the re-gear. They told me that they have rarely have done this type work. I have had several excellent experiences with Highlift Off-road in Cincinnati and will probably have them do the work if I decide to move forward. My big concern currently is trying to figure out the inconsistency of whether the 4.88s will fit in the front axle or if I would need a different whole front axle assembly?

 

[Boostnu]

I completely understand about allowing the dealership do the re-gear. They told me that they have rarely have done this type work. I have had several excellent experiences with Highlift Off-road in Cincinnati and will probably have them do the work if I decide to move forward. My big concern currently is trying to figure out the inconsistency of whether the 4.88s will fit in the front axle or if I would need a different whole front axle assembly?

They will fit. I run 5.13s in mine. They need to get the jl jt specific gears.

 

[Dls79]

I’m curious why the dealership parts guy would look up the build records using my VIN and tell me that mopar 4.88 gears would not physically fit into my 210 front axle differential housing?

 

[TheSolarWizard]

I’m curious why the dealership parts guy would look up the build records using my VIN and tell me that mopar 4.88 gears would not physically fit into my 210 front axle differential housing?

because those people are typically on par with the average 9 year old equipped with an iPad knowledge wise. you can regear your axles

 

[KevinC]

Going from 4.10 to 4.88 is not that much of a difference with just a 35" tire. You may be disappointed in not achieving better gas mileage numbers going to 4.88.

I understand you are carrying a lot of weight and that is your vampire on gas mileage. Not seeing 8th gear on the highway is also due to weight. It's like pulling a trailer behind you. I'm not sure that small of gear change is going to help.

 

[sl65racer]

37” KO2s and 4.88s get me around 18 mpg and I see 8th gear all the time. But I’m not heavily loaded.

 

[hjdca]

I have a 2021 Gladiator Rubicon that I’m running Nitto Ridge Grapplers (315x70Rx17) a Smartcap with roof rack with a cargo box and 270 awning. I also daily carry a lot of weight in the bed. I also occasionally pull a small trailer. I rarely see 8th gear although I do about 15% interstate driving and about 20% medium intensity offroad driving.. the remaining use is local rural county road (rough gravel often). I currently average 13.4 mpg with my auto transmission and 3.6 Pentastar.I believe that I would benefit from deeper gearing. My local dealer is trying to discourage re-gearing and even had told me that because my truck has factory 210 front Dana 44 front axle (220 rear) the 4.88 gearing will not physically fit in the front pumpkin. What dos the forum say?

Re-gearing will help you with acceleration. You will feel a difference going up the on-ramps. I also have a JTR, and I went to 5:13s, but, I run 37" tires. If you plan to stay with 34.5" tires, 4:88s should be enough for towing. If you plan to go bigger tires and still tow, you might want to consider 5:13s. I went with Dana Spicer gears - they have a stellar reputation and come broken in from the factory. No issues after 46K miles With all the weight and towing, you should consider running Mopar Synthetic 75x140w. This is what I run both front and back. Note: I also have thick Nodular Iron diff covers and I live in an area that get very hot in the summer, so, I am concerned with heat.

 

[Dls79]

Thank you.

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