[buildingjeeps]

I know I'm gonna put 37" tires on a JK unlimited rubicon.

I have sooooooooooooooooooooooooooooooooooo many questions, I don't even know where to start..............

[wrnglrguy]

Start here...

http://www.jeepforum.com/forum/f96/jeep-jk-frequently-asked-questions-326818/

Then, understand that you will need to regear. Also, the lift height required for 37's (4" or more), you should STRONGLY consider swapping your driveshafts for ones that have u-joints on either end (especially if you plan on going off roading). Other then that, fire away with your ????

[Prot]

4.5" to 5" lift, driveshafts, 5.13 gears and deep pockets are required.

[Warlord2]

its really not that hard, Ive heard a little shaving is required, but all you need is a good 3" suspension lift and a 1" BL. Of coures you need to regear, and atleast one aftermarket driveshaft.

[BigJerm]

So I am nowhere near 37's but Ive been around a friend who went from a stock Rubi to 37's. He got the Teraflex 4" kit (not long arm) and it actually gave him 5", 4.5" after the AEV front bumper. He is on 4.10 gears right now because he is waiting for a new gear that is in the works (dont ask, i dont know). He also was on stock driveshaft’s. He had to replace the rear because he slid off on a rock and dented it pretty bad.

So yes, 4" at least of lift, I would say 4.5" at least. No you don’t need new gears to drive it but you will probably want to kill yourself while driving... and the Driveshaft’s... well.. those seem to be hit and miss. People have DS failures everywhere from stock to 2.5" to 4" of lift. Either way, they will go, just a matter of time.

[jeffmarion]

Originally Posted by buildingjeeps

I know I'm gonna put 37" tires on a JK unlimited rubicon.

I have sooooooooooooooooooooooooooooooooooo many questions, I don't even know where to start..............

I have a 4 door on poly performance 4.5" lift springs. I had the 4" superlift before these. Anyway gears will be needed to get the power back. On a 4 door I would look at getting a front drive shaft. Although I ran the stock one for over a year, and 20K miles and did not have a problem. I was one of the lucky one. I recently replaced the front shaft just in case, and because the poly lift is actually closer to 5.5" and the driveshaft angle was already bad with the superlift 4", the extra 1.5" made it that much worse.

[buildingjeeps]

Thaks for the link. It was helpful to calm me down a little.

I've accepted I'll need to regear ... that is the only new thing for me since my TJ Rubicon has an RE 4" long arm and a Tom Woods drive shaft to clear 33" or 35" tires, now for sale to make a budget for the JK (http://www.buildingjeeps.com/forsale/).

You see I want to build the JK to be "worry free" and last long and handle like stock with good parts. Since I don't care much for new bumpers, rims, winches, lights, etc, it gives me more of a budget to do the suspension right for off-road and daily driving, so...

A long arm would cut too much into the budget, so what is the best quality/most complete regular length arm kit out there? What are the disadvantages of a regular length arm kit, any? (for a TJ, Rubicon Express is my favoriate choice, but they don't seem to make a 4" short arm for JKs... I wonder why?)

How about drive shafts? Who makes the best ones for JKs? What are my choices? Same questions for gears.

Do people find they need to disable the ESP with 37" tires?

With little kids, this time I want softer shocks. Any suggestions? It probably heavily depends on the brand of lift kit I get, right?

[That1guy]

Can a X model with the 30/44 combo handle 37's?

[BigJerm]

Originally Posted by That1guy

Can a X model with the 30/44 combo handle 37's?

I only know of one guy in 2dr who did 37's on stock D30. HE has broke 2 axles. I know one time it was because he had 4wd engaged when he hit pavement and did something funny, the other time I am not sure how.

[Prot]

The Bilstein 5100 shocks I have are supposed to be for 4 - 4.5" lift. My Black Diamond 3" lifted really gave me over 4" of lift. My ride quality on the street is actually better than stock (as long as some nimrod doesn't overinflate my tires). It just seems like there is a big jump in price all the way around between 35's and 37's. Not only the price of the tires, but the price of lift and extras like driveshafts. If a person is starting from a Sahara or X, then front axle replacement should also be considered for 37's whereas they are fine for 35's. I have also heard of people putting 42's on a Rubicon, but that's getting crazy there and more of a trailer queen than anything.

What I like about the Bilstein shocks is they are specifically valved for the JK. I don't care what anybody says, buying shocks based solely on length is a bad idea if you care about ride quality on the street. Valving for a superduty truck is going to be different than a light vehicle.

[AZ Bulldog]

Originally Posted by That1guy

Can a X model with the 30/44 combo handle 37's?

I've put over 8k miles on my set-up D30/44, I wheel it every weekend and haven't had a problem yet. I know that someday the front will give out and then I'll get the Rock Jock 60's and be done.

Here's a poser shot from Saturday.

[BigJerm]

Originally Posted by AZ Bulldog

I've put over 8k miles on my set-up D30/44, I wheel it every weekend and haven't had a problem yet. I know that someday the front will give out and then I'll get the Rock Jock 60's and be done.

Looks good. Have you done anything to the axles other than the ARBs?

[AZ Bulldog]

Originally Posted by BigJerm

Looks good. Have you done anything to the axles other than the ARBs?

Nope just gears and lockers, so far so good but I live in the real world and understand that it wont last forever...

[buildingjeeps]

Thanks for the info on the Bilstein 5100. I agree.

So I realized I can't keep the stock rims and go to 37" x 12.5 tires and a 4" lift because of the width of the rim, right? The backspacing you can deal with with spacers.

So, if I want 17" rims to hold 37" x 12.5 tires, what rim width do I need and what backspacing, so I can shop for a rim I like?

[jayburd8]

Originally Posted by buildingjeeps

Thanks for the info on the Bilstein 5100. I agree.

So I realized I can't keep the stock rims and go to 37" x 12.5 tires and a 4" lift because of the width of the rim, right? The backspacing you can deal with with spacers.

So, if I want 17" rims to hold 37" x 12.5 tires, what rim width do I need and what backspacing, so I can shop for a rim I like?

17x8 would be a good choice. The narrower the rim, the better it will hold a bead when you air down. A wider rim will give you a wider contact patch and better (in theory, at least) tire wear. A compromise might be a 17x9. Personally, I'm getting a 17x8. I don't think backspacing will be a problem on aftermarket wheels. 4.5 should be reasonable. Jeeps bolt pattern is 5 on 5.