burbingus

Hey guys,

The question often comes up about what is necessary to run 37s on the Jeep. When I had just bought my Jeep, I did a lot of research into preparing my Jeep for upgrades becasue I wanted to do it right the first time. Anyways, I thought I'd share a little about my experience with 37s.

I have a 2007 Unlimited X with a D30 up front and the D 44 in the rear that is my daily driver. Before lifting the vehicle, I wanted to ensure my driveline was up to the task of running 37s. I was concerned about the stress on the axles and transmission in particular. I took care of the transmission with a cooler, and honestly, I think it has done pretty well. As far as the axles were concerned, I had the front sleeved and gussetted with the EVO sleeves and gussets. I had 5.13s and ARB air lockers installed front and rear, and I had Superior alloy axleshafts added front and rear - 30 spline front, 35 spline rear. Based on what I had read, this should have done the job as I wheel pretty gently - slow on the accelerator, and I ease down obstacles.

I lifted the vehicle 4.5-5" and addeed 37" GoodYear MTR-Ks, one of the lightest 37" tires I could find. Nevertheless, I still needed needed to upgrade the front brakes, and the balljoints had to be replaced pretty fast. I also needed to get a drag link flip kit to help with steering. Even with the precautions I took before I ever lifted the vehicle, my front C-arms have still bent slightly causing the passenger side caster to be slightly out of spec - not terrible, but still off. Also, my rear axleshaft flanges have bent (possibly the front as well) causing my ABS/ESP sensors to go wonky.

Because I'm back in school and not working at the moment (suger mama at home ) I'm going to be going down to a smaller coil spring and tire in order to maximize the life on the components until I can afford to replace both my axle assemblies with D60s. If I had known how much time and money I would spend upgrading the axle components while still worrying about the wear and tear on them, I would have gotten new axle assemblies put under it first for sure.

Bottom line, as a newbie, I had hoped my experiment with D30/D44 and 37s would work if I did it the right way. However, I think the money would be better spent upgrading the axle assemblies before putting 37s on.

Hope this is helpful

Micah

Cobb_Sahara

Thanks for the info. Did you go straight from stock tires to the 37s?

burbingus

Yeah. A week or two after I beefed up the drivetrain, I lifted the Jeep and added the 37s, switching over from the stocks.

Redman333

How much did you spend on beefing everything up?

Tvernon

I have been telling people this for years, and most people still wont listen. However, your lift height shouldn't matter too much so I would just keep the springs you have. To fix your C's, heat em up and beat them back into submission until they're in spec. You can do this, or take it to a colision shop to do it for you. Another option would be to buy a "brand new" D30 carrier. Most junk yards would give them away just to get them off their lots and all of your internals would still be good. But with that, ditch those C gussets and axle sleeves which do little to no real good. Artec makes a killer D 30 truss That would solve the strength issues.

If I were in your situation I would buy a new D30 housing for the time being, and then the truss for a 200 bucks.

Just my .02. Good post.

burbingus

Including the steering, brakes, lockers, gearing, etc. just for the front that are strictly D30 components (can't be reused) would come close to 2500. Some of that is parts that would have to be purchased for whatever axle you're getting (axleshafts, steering, etc.), but still it's parts that would be better off being purchased for a beefier setup.

Thanks for the advise. My caster isn't off that much, so I'm probably going to keep the front axle housing the way it is. In about 18 months I'll start saving up for D60s front and rear to replace my setup, and I'll go back up to 37s then. Also, the only reason I'm replacing my springs is because the vehicle would look pretty goofy with the tall lift, flat flares, and 35s.

Micah

pcc999

really? wow

crazyhorse02

I dont think the 37's had anything to do with your issues. A D30 housing is identical to the D44 housing the pumpkin is larger and houses a 44 instead of a 30. Your lift height is probably the culprit of all your issues, not necessarily the height, but rather the lack of being properly aligned. To bend your axle C's with the EVO kit installed is not impossible but remarkable, they are pretty stout and can handle a good amount of abuse. If you would have shattered your ring and pinion, snapped some axles etc. then I would look at the locked 5.13 D30 as the weak link, but housing issues. I doubt it. I'm not recommending 37's for a D30, but for your particular situation look somewhere else for your front end woes.

crazyhorse02

Your castor is adjustable with control arms, it's your camber that cannot be adjusted.

RWJ

I upgraded to a pro rock from dynatrac and it adjusts for camber. I run the mtr Kevlar 37 inch and the prorock handles them just fine. Alignment is better and ride and handling improved. The down side of the prorock is the cost. I have the flip kit and Teraflex long arms. Good luck getting the final upgrades completed to get the ride you are looking for.