February 11, 2018 at 9:41 pm #200520
Guy MinerParticipantArea Coordinator
Dan, not a lot of Jeep-mod talk here on NWOL. So, here’s some thoughts based on my experiences and observations:
37’s are a LOT of tire. This is good. But, that’s a LOT of tire!
The 3.6 Pentastar V6 makes good power. 285 hp! Good torque too. But… it’s not a bottom end 1000 – 2000 rpm torque monster. It runs fine down there, but doesn’t put out a lot of power at those rpm’s.
Consider dropping the gear ratio to… 4.56 or so. Maybe 4.88’s. An air-locker or a pair of air lockers (or electrical, or manual) installed at the same time makes sense. I have seldom used my front air locker, but have often used the rear locker. I swapped my open diff, 3.21 factory gears for 4.10’s and Yukon air lockers. I’m running 33’s, 285/75/16’s, E-rated all-terrains.
BTW – your Jeep comes from the factory with a very good electronic traction control. The “brake diff lock” or whatever they call it is just an electronic way of controlling wheelspin, and it actually works really well. If one wheel starts spinning, the computer will brake it, and the opposite tire (hopefully with better traction) will pull rather well. I wheeled all over the place for two years with stock gears, and open diffs and did just fine. Later, after putting in the air lockers, I still wheel with the diffs “open” most of the time. Rarely have to engage either locker. Your dad is nuts and just goes everywhere with his open diffs. 🙂 His Jeep takes care of him despite his tendency to use the skinny pedal to deal with every off-pavement situation! 🙂
The front Dana 30 on the “sport” model is adequate, but not heavy duty. I recently upgraded mine with stronger axle shafts & bigger U-joints. That’s a pretty simple upgrade, or there are lots of Dana 44 and Dana 60 conversions avail if you want to spend more money. I’ve been a lot of places with that Dana 30 though, no problem for overlanding is my impression. But, I’m not running 37’s.
Weight – even my 2-door comes in at 4,600 pounds! I know guys with built 4-doors hovering around, or exceeding 7,000 pounds! That’s a lot.
Be sure to stay aware. You’ll probably go over the factory GVWR very quickly. Many of us do, and I don’t know anyone who had a problem as a result. It’s worth knowing though.
LOVE removing the doors and top for a few weeks every summer. It bites me every now and again. I remember scouting a route for the NWOL Rally in 2016… No doors, no roof. Wearing my Gore-Tex parka ’cause it was snowing and raining on Sugarloaf! 🙂 So, remove them if you want, it’s easy and fun. But, bring a jacket. This is the Northwest.
I thought an 8,000 pound winch would be adequate but went with a 10,000 pound unit. It has worked well. Seldom have I needed it for my Jeep, but I’ve moved a lot of fallen trees and have winched a couple of other vehicles out. I like a big winch, the bigger, the better.
Weak spots on the JK include the infamous “clockspring” in the steering column. It’s a poorly designed electrical connection, prone to failure but well known to Jeep dealers. Talk to Rich for inside info on that! The front axle is fine for stock, but with 37’s may deserve some attention. The 4-wheel disc brakes are good, but there is an upgrade kit avail.
Does yours have that absurdly large speaker in the rear cargo compartment? Mine didn’t include that. If it had, I’d have thrown it out long ago. It takes up important cargo space!
There’s a million things you CAN do to the JK, but few that you MUST do.
Regards, GuyFebruary 12, 2018 at 3:00 am #200525
Dan, what a great idea for those flashlights. I may have to copy that. Think that they would work in a 4Runner too, 🙂February 12, 2018 at 8:39 am #200531
Guy MinerParticipantArea Coordinator
Oh – and the dreaded “death wobble.” It’s a real thing.
I hope that when your suspension was installed, they also beefed up the front end & steering components: track bar, tie rod, etc… That can help a lot, preventing the dreaded death wobble!
GuyFebruary 12, 2018 at 9:08 am #200536
Thanks for the info! I will start to catalog that. I am sure there is a lot I need to do but my focus right now is to drive. But these will be all sweeping changes.
DanFebruary 12, 2018 at 6:24 pm #200565
Kevin GrahamParticipantPremium Member
I am psyched to see where you go with this. I have only sat and chatted with you once, but I know that you are going to go with a dedicated expo rig. Mine was a blank slate up until a month ago, and then I went crazy. I haven’t used Vision X lights, but I know they have a good rep. I have JW Speaker for the headlights, factory fogs and tail lights. I am sure you probably know about the need for anti flicker stuff in the JK, but I wasn’t willing to have any extra things to figure out where to house, with JW they were all built in. For carrying the 37, I have an AEV bumper and fuel caddy. Love the way it ties in to the frame. The water tanks are a little hokey, but the fuel caddy is awesome.February 12, 2018 at 9:13 pm #200567
Thanks, Kevin! I am super stoked for this beast. It will be a great ride, more than it already is. So, stay tuned!
DanFebruary 12, 2018 at 9:36 pm #200569
Guy gave you tons of advice that is right on. I’m a 4Runner guy, as you know, but have talked with my favorite shop owner a number of times about JK’s. The one thing he says that you should watch are the rear wheel bearings. In fact, he says they are one of the primary weak spots on these Jeeps.
As far as regearing is concerned, my 5th gen 4Runner came with 30″ tires and 3.73 gearing. I went with 32.8″ Cooper ST/Maxx tires in 255/80R17 size. These are a nice tall, thin tire that really has worked well for me. Better than BFG ATs in my very personal opinion. I had to raise the suspension to clear them, but had done that anyway with OME medium duty springs front and rear, Bilstein 5100’s up front and OME Sport shocks in back. Originally had the sport shocks in front too, but they don’t work well there. Too spongy and excessive cupping. Also had a set of heavy duty rear springs, but went with the medium duties for a better ride. Honestly probably could have done with just regular OME springs in the rear and I carry or tow a lot of Stuff. The original gearing made the engine act as if it had emphezema. Out of breath on any type of hill. So I regeared with Nitro 4.56’s and really love them. I knew in advance that these gears would further decrease the gas mileage, but am very happy with how much better the whole system operates together now. If you do regear, call Nitro and get their opionion. I’m guessing they will say 4.88’s. My 4Runner has ATRAC and DAC, so I decided against lockers. I no longer do the crazy stuff I used to do and find that they, alone with the 4 wheel low gears keep slippage to a minimum and aid in safe downhill passages.
I know most of my knowledge is with Toyotas, but I think that Guy is also right-on about the incredible advances made in the past few years with electronic controls for tire spinning and downhill descents. So really think about whether or not you really need lockers for the type of “overlanding” you plan on doing. You may want to spend that money on something more useful. BTW, I went with a ComeUP 9.5 ton winch and wouldn’t want anything smaller. These vehicles are heavy!! This winch is made to work in both directions; sometimes you may have to winch yourself back down a hill tailend first. Read up on winches and you’ll see that a lot aren’t built to do that.
Hope this helps.
DaleFebruary 12, 2018 at 9:40 pm #200570
BTW guys, if this “death wobble” is such a terrible thing and is such a well know phenomenon, why hasn’t Jeep done something to cure it? Is it a sign that one has too much weight over what the vehicle was designed to handle?February 12, 2018 at 9:45 pm #200571
Thanks for the input, Dale! Yeah I see mu list getting longer LOL!
The death wobble is more isolated to straight axle trucks. Rovers were notorious for this type of trauma. Re-enforcing the geometry and steering bits helps a lot.
DanFebruary 13, 2018 at 9:33 am #200586
Kevin GrahamParticipantPremium Member
If you are going to be at the Seattle/Eastside meetup, I am planning on heading down for it. Unfortunately I have to be at a funeral that day, but I’m thinking I could use the drive that night. I am on 37’s with 4.88. You are more than welcome to take it for a spin. I went back and forth between 4.88 and 4.56, but pulling our camping trailer and still having the desire to head back to Rubicon and Dusy Ershim yadda yadda yadda went 4.88’s. At 70 MPH I’m just a hair over 2500 RPM.
I haven’t heard about rear wheel bearing problems before. Granted, mine is still fairly new, but my wife and I bought her 2007 new. Now with 110,000 miles, 80000 of which on roughly 34″ tires and haven’t had any problems in the back to speak of. I also ran JK axles under an LJ for around 20000 miles with 35’s then 37’s without issues in the rear axle. The front is a different story….
For overlanding only, the Dana 30 “should” be okay. Inner C’s and passenger side axle tube don’t do well with the extra leverage from the 37’s. They will also get to the ball joints pretty quickly. The Rubicon 44 front has the same inherent problems. The good news is they are plentiful. Heck, I have a Dana 30 in my garage right now out of a 2016 JK that I would love someone to take.February 13, 2018 at 11:53 am #200589
Benny BensonModeratorArea Coordinator
Dan, I’d say a majority of the death wobble in JK’s is from a loose or damaged front track bar. It’s usually the frame side bushing or the bolt is loose. Every oil change, throw a torque wrench on it and make sure its at 130ftlbs. 2nd is the craptastic stock ball joints. I had to do my 2013’s at 30K.February 13, 2018 at 12:13 pm #200592
Patrick TingleyParticipantBasic Member
Mine was the horrible steering components, I had the factory Y style steering that I changed to T style, I also have a steering box brace, a bigger steering box, I also have dual opposing stabilizers and an upgraded anti sway bar, and a MUCH control arms, better track bar, and MUCH better ball joints. Take your pick because any of them can cause death wobble, especially when you start running heavier tires. And with the little front axle I would not be surprised if the housing flexed, so a truss might be a good idea, especially considering the weight of your rig.
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