JKtough82

Im looking at throwing some 37" tires on the JK this spring and trying to get things in order for the upgrade.

My question pertains to gearing...
The rubi comes with 4.10 and lockers front and back. Changing to 37s... i'm thinking it would be better to upgrade to 4.88s... but would i need to upgrade my lockers to the new gearing?

Thanks!

Chuck-The-Ripper

I guess you didn't make it very far with your original build from 2011

karls10jk

The gears you're talking about upgrading are bolted to the locker so you'll be upgrading them when you change the gear ratio.

It's best to approach a new topic with as much info as you can before you commit to purchase otherwise you may get taken for a ride.


That being said- 37's are a big step to take if you've not done your research.

JKtough82

Maybe not as far as some... but i did lift it with a 3.5mid X from Rock Crawler, added some flat flares, new axle, new wheels and 35" shoes, a rear locker (i cant remeber the manufacture), intake, and my final addition was a XRC front bumper. Then life happen and i needed to sell it. Was a bitter pill to swallow but now i have 2016 Rubi and this ones going no where.

scooby snacks

I'm running 4:88's on my Rubi with AT and 37's (3.6 motor). You'll need a ProCal or other tuner to keep from going into limp mode after the upgrade. I recommend gusseting the C's and sleeving the axle tubes. I did both and upgraded to chromoly axles. After some mileage was put on the 37's, ball joints had to be replaced.

Good Luck!

JKtough82

i don't mind doing my research and i was just online reading other post and i figured i would drop question on the forum.

The JK isn't my daily driver and frankly i could let it sit in the garage till next winter while im working on it. Besides the locker addition to my 08 JK, i did everything else my self. Being a Vehicle engineer for Xerox, im a pretty hands on guy, its what i get paid to do... The 37" upgrade isn't want scares me, or the upgraded drive or axel shafts etc to support the larger and heavy shoes. The D44 arnt going to have trouble turning them on anything we have here on the east coast within reason hehe. Even the big breaks to stop a 37" (average weight of 68-71lb) tire isn't much of a challenge. Honestly, I dont like gearing, its just one of those topics i dont like. I don't like messing with gears in anything. Reason being is i don't have the tools to do it. Ive never seen the inside of the dif.

JKtough82

Thanks Scooby
Good Info. I was looking into the ball joints last night.

So far i have been looking at the following list as required for my 37"

Lift- 3"+
Ball Joints
C gussets
Truss
Front and Rear axle shafts
Drive Shaft
Gears - 4.88 ??
Wheels with min of 3.0 or 3.5" ??


Electronics
Programmer
Big Brake upgrade

Might be a few things missing...

karls10jk

37*13.5 with aftermarket wheels weigh in at a cool 110lbs each, so big brakes are probably higher priority than most make them- here on the East coast.

I can't speak for 12.5" wide tires but the 13.5" really needs the extra bs of 3.5".

Canvas

I upgraded to the Ultimate 44 last spring and prior to installing it I had an Artec Truss kit installed. The reason I did this was for the added security. Sleeves work for some but depending on what sleeve you use you compromise the housing by drilling into it for the rosette welds. The Artec truss provides the added insurance agains breaking.

As for the upgraded drive shafts I would recommend the Adams 1310 simply because that is what I am running. Chromoly shafts with Spicer U-Joints will serve you well. Keep a replacement U-Joint for the axle and drive shaft handy for those times you are just having way too much fun.

As for upgrading the the lockers, you will not have too. They are designed to work with 3.73 gears and higher. Where you would run into issues is upgrading 3.21 gears, that is when you would need a new gear carrier.

Last thing, be sure your gear selection matches where and how you wheel. If the 4.88 is going to be on the lower end of your performance spectrum bump up to 5.13's so you only pay for gears and labor once.

R/
Will

JKtough82

Thanks all for the additional info.
Going to start looking over some reviews for the identified parts. I'll post some pictures as the parts arrive.