Sponsored

Gear ratio for Manual and 37s

21Moja

Well-Known Member
First Name
Chris
Joined
May 20, 2022
Threads
48
Messages
457
Reaction score
315
Location
CT
Vehicle(s)
21 Gladiator Mojave
Occupation
Master Distiller
I know there are a ton of threads about this but I see many talking about regearing for automatics and not much talk about the manual...I am running 37s right now, about to go under the knife for some Yukon gears. I am deciding between 4.88 and 5.13, have no plans to go bigger than 37 but my dilemma has more to do with final drive ratios on the manual and whether the 5.13 would make 6th gear more usable. I have heard many talk about the manual being a 4-speed with 2 overdrives, I want to make all 6 gears a bit more usable. Without getting into a giant debate on whos is bigger I'm hoping to get some real-world opinions on 4.88 and 5.13 in a manual...

I dont tow much if ever, never know...

I go to Wyoming and Montana often for fly fishing trips...
Sponsored

 

Bbannongmu

Well-Known Member
First Name
JTR.Spartacus
Joined
Jan 18, 2020
Threads
34
Messages
2,146
Reaction score
2,531
Location
Earth
Website
m.facebook.com
Vehicle(s)
2020 Jeep Gladiator Rubicon
Build Thread
Link
Occupation
Certified Emergency Manager
Vehicle Showcase
1
I know there are a ton of threads about this but I see many talking about regearing for automatics and not much talk about the manual...I am running 37s right now, about to go under the knife for some Yukon gears. I am deciding between 4.88 and 5.13, have no plans to go bigger than 37 but my dilemma has more to do with final drive ratios on the manual and whether the 5.13 would make 6th gear more usable. I have heard many talk about the manual being a 4-speed with 2 overdrives, I want to make all 6 gears a bit more usable. Without getting into a giant debate on whos is bigger I'm hoping to get some real-world opinions on 4.88 and 5.13 in a manual...

I dont tow much if ever, never know...

I go to Wyoming and Montana often for fly fishing trips...
I am on my way back to Pennsylvania from Yellowstone- Wyoming, Montana and Idaho. I did 5.13 gears and I am sooo glad I did. I was able to use 3rd gear in the 10 % grades of Teton Pass. The 3.6 wheezed some but the gearing made it possible. I had to use 5th gear a lot (and sometimes 4th) on I90, I94 and the hills of US 191 to maintain speed.
Pm me if you have questions
 

AustinL911

Well-Known Member
First Name
Austin
Joined
Jun 18, 2019
Threads
32
Messages
500
Reaction score
672
Location
Central Ohio
Vehicle(s)
2021 JTR 6MT
Occupation
Nurse
No real world experience (yet), but I've researched the shit out of this.
Overall consensus for the MT seems to be:
35s > 4.88
37s > 5.13

The factory 4.10s are borderline undergeared on the JTR/MaxToes and the 3.73s on everything else is for sure undergeared. Factor in extra rotational mass of a larger tire plus getting it into a more usable range than the factory gearing provides, even in stock configuration, and I think you'd be better off going up a few notches on gearing.

If I was towing a ton with the MT, I'd go 5.13 with 35s and 5.38 with 37s. I don't think anyone has done that yet though because of the severely limited tow rating on the MTs.
 

willhonkforparts

Well-Known Member
First Name
Justin
Joined
Jan 7, 2022
Threads
20
Messages
308
Reaction score
411
Location
Canada EH!
Vehicle(s)
2021 JTRD & 2008 JKUR
Occupation
Self-loathing
5.13. The mechanical advantage is greater than the slight loss of fuel economy at high speeds in 6th. If you run a large 37 (as opposed to a Ko2 which runs small) or if you think you might ever go to 40s, I might even consider 5.38s
Sponsored

 
 







Top