Ok I have 08 2dr sport with 3.73 gears with magnaflow exhaust, banks intake afe throttle body spacer and superchip programmer and im wondering if I can run 37s.... I have a 3" lift with flat flares. Stock driveshafts... I do wheel probably 8-10 Times every summer and drive about 8-10 thousand miles a year... Just looking for some advise or what to do or not to do.
Thanks guys

 

Theres gonna be a ton of people responding telling you not to run 37s on a dana 30... and for the most part, they are right. You can spend a ton of money and beefen up your front axle but it still will be dicey when running 37s. Not to mention the gear ratio. 35s and 3.73 can be a real dog while driving up hills, even with a manual tranny it can be a dog.

 

The only problem is the gearing will make it sluggish but once you get around to re gearing it will be fine. And yes this thread will prob be taken over by rubicon owners telling you the dana 30 is shit but not to worry there are plenty of us out there driving 37s on dana 30s with no problems

 

I reccommend chromo shafts front and rear and gusset Cs on your front axle. 37's are a lot of tire and heavier than crap. I hear the stock steering box will eventually fail just be aware.

 

You can run 37's. I'd look for the lightest 37 I could find (KM2 maybe?) running them on a D30 with 3.73 gears. Ball joints, axle tubes, ring and pinion gears, steering box, axle shafts, etc all become more likely to fail, bend, or break, but of course you already knew that. You'll lose a mpg or two and you pretty much lose top gear, but you knew that too.

 

You are going to hate it if you stick with 3.73's. Plan on having no power and horrible gas mileage. You will have to regear or it will be miserable

 

I drove around and wheeled the JK for a year with 37" Nittos before I went to 5.13 gears. I had 3.73 gears in my D30 with just EVO "C" gussets and I have the 6 spd as well. The manual tranny will make a big difference when running 37's on 3.73 gearing. I basically lost 6th gear. I didnt mind it. Only reason I changed gearing is because I want to a PR44.

 

Does anyone know the lightest 37" tire it there?? Preferably a mud terrain

 

My guess is the BFg km2 as they run a bit smaller than other tires

 

Yes you can.

With Teraflex front extended bumpstops and 37s on 4.5" or less backspaced wheels, if you adjust your steering stops, you won't have rubbing issues.

You will need an aftermarket front bumper or a stock bumper cut to a stubby.

For the rear, you will need to either run 4" extended bumpstops or do a fair amount of trimming in the rear fender well with 3" extended bumpstops.

You will need to trim the front edge pinch seam of the rear fender wells.

If you have an automatic with 3.73s, running in 3rd gear--with the overdrive turned off--you will turn the same rpms as you would in 4th gear with 5.38s. This is a good rpm level for highway driving.

If you have a 6 speed, just run 5th gear at highway speeds and you'll run the same rpm as the automatic would in 3rd gear.

The stock tire carrier will not handle a 37. So, you'll need an alternative.

Your mpg around town will go down until you regear.

Wheeling with a 6 speed, 3.73s and 37s in technical types of terrain will be hard on the clutch.

The front D30 will last a while if it is unlocked and you don't offroad with a lot of wheel spin.

You could weld on C gussets to prevent them from bending.

I would not suggest you put any additional money than front C gussets in your axles if you are going to run 37s.

You can buy a pair of takeoff Rubi axles that have already been regeared to 5.13s or 5.38s for about $3500 or a pair that hasn't been regeared for about $2500. Although, 4.10s are not enough for 37s.

Even a front Rubi axle should run C gussets and sleeves or a truss with 37s. I'd do the Artec if I was you.

Then, you can sell your stock axles to offset the cost. The net cost will be less than regearing, doing lockers and chromoly shafts to your current axles.

With a lighter 2 dr, if it is an automatic, you can likely get by with stock Rubi axle shafts. The tranny allows more slippage and doesn't load the drivetrain with the same shock as a 6 speed offroad.

I you wheel hard offroad, lockers in,with a lot of tire spin, the stock Rubi shafts will not survive.

With a 3" lift and 37s on a 2 dr, you will eventually need to upgrade driveshafts, but it might be more than a year or more before you have problems with the stock driveshafts.