37s questions
 

So I was about to buy my 35s when I found a deal and a 37 is only $15 more a tire. What would I need to run these on a 2.5 lift? Would I need a larger lift? Also as far as power goes, I have a 3.6 with the 6speed in my 2 door and 3.73 gears? What would I need to re gear to or is it necessary? Also how would this effect power, mileage etc? Really thinking the 37 would be the way to go if I can figure it all out, thanks!

Also I have the smittybilt flares on

Do the 37's because eventually you will anyway. With the 6 speed you maybe able to tolerate the 37's for a while but may want to consider 5.13's down the line. 2.5" with 37's will likely require some trimming if have not done any. Your power and mileage will be affected negatively. But how negatively will be contingent on your right foot.

I have a friend that runs 37s with a 3.6 six speed and 3.73s. He was daily driving it till he got his new work truck. Said it wasn't bad, he just pretended like it was a 5speed. He has 3.5in lift and flat finders and rock crawls the crap out of it.

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People will tell you what you want to here. Truth? I ran 3.73s on that setup and it sucked. 37s would really suck. Not to mention the stress it would put on your drivetrain. Your clutch will especially feel the love. You obviously don't have a rubicon, so anything offroad other than trails will be terrible.

Do it right or don't do it. Also, that front axle of yours is not designed to run a tire that large. Following that comment will be people saying they did and it works. Ironically, one of the biggest advocates of D30 and 37s on another forum just blew up his front ring and pinion this week while idling over a rock. You'll need to truss the housing if you don't want a bent axle. Although, you should do that with 35s too.

That's not the way to do 37"s. If you think you want to do 37"s then hold off for a bit and plan your build out. Half ass and 37+ tires do not go together.

I agree, I have 37's on a 4" lift but I have a Rubicon and it handles great rock climbing and I drive it as a daily driver and get 15 mpg. but in your case I would stay with the 35's until you can at least upgrade your gears or you are asking for gear and clutch problems. My best friend just snapped his rear axel with 37's and 3" lift due to having a base 4 door and it was an automatic, and the terrain wasn't that extreme. Wear and tear will get your weakest link.

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I had 2.5"lift 37s,3.6,6 speed,smittybilt flares, I had 3.73 now I have 5.13. It's not the end of the world if you don't regear right away. Just sleeve and gusset your Dana 30 and heavy duty ball joints.

Be prepared to trim the rear pinch seams right to the tub and put on some flat fenders on. 2.5" is likely gonna rub. When flexed.

3.73's, 6 speed, and the 3.8l here. It was doable but only for looks. I had an extra set of tires and wanted to see what it was like. Aside from the major power loss, I could feel the steering pump screaming to take off the 37*13.5's. It's not something you want to live with.

Your better route on this would be to buy some used 37's that are at the end of their life and try it out. Get everything together for them. Realize you hate the downfalls and go to a 35 with everything strengthened up already. You also need to consider brakes, steering, and clutch life with larger tires. The brakes don't grab as well, the steering pump will want to kill you in your sleep, and the clutch needs more throttle to get rolling. Downshifting will be incessant unless you'd just like everyone to zoom past you on the interstate.

I've now got the 37*13.5's on a 2015 Rubi (4.10/ 6 speed) and while it is a little better, it's not better enough to where I would want it everyday.

I think I may stick to the 35s. Even with the 35s I planned on beefing up the Dana 30 in the front for sure. I was going to get the truss and gussets for it. Should I go ahead and sleeve it too? I know it can handle the wheeling I do now but I keep getting into rougher stuff and I know with 35s I'm going to keep pushing it so I'm thinking that for the $500 or so to beef it up it should hold up for what I get in to. I don't do any major rock climbing out here. And as long as it holds up strong (knock on wood) when the day comes that I want to buy built 44s and run 37s, I should be able to get a decent resale on the built up 30.

Does anyone have any experience with lockers in the 30 and/or any build list that they may have done to theirs.

Also if anyone has in misc axle junk or setups laying around I may be on the market ;)

Thanks for the help guys!