Changing Axle Gears in my 2008 Jeep Wrangler JK Rubicon

2008 Jeep Wrangler Rubicon

RPMs at 70 mph with 4.10 gears with 35 inch tires.

RPMs going 70 mph in 4th gear with the stock 4.10 axle gears and 35x12.5r18 BFGoodrich KO2 tires.


RPMs at 70 mph with 5.13 gears with 35 inch tires.

RPMs going 70 mph in 4th gear with 5.13 axle gears and 35x12.5r18 BFGoodrich KO2 tires.


changing gear oil

After 1,000 miles of driving with the 5.13 gears I drained the rear differential case. This was the horrible looking oil that came out. Got me a little nervous that something was wrong. I then drained and replaced the front differential case and the oil looked the same color as well. A couple thousand more miles and I checked the rear oil and it is the pretty golden yellow color as it was when I replaced it. My guess is the shop used some funky conditioner or something that made the opaque silver color.


I will always remember my last trip in my old heavily used 1991 Montero. That trip was to Scout Camp with KB on the East Fork of the Bear River in the Uinta mountains, the last week of July 2018. What a fun trip and great farewell to an old friend that served me well even though she was run down the day I got her over twelve years ago. The Montero ended up being the best $300 dollars I ever spent.

With the passing of my Montero I was in the hunt for a good 4x4 SUV that would take me into places like a side by side ATV. After a long and exhausting search I found that the best option for me was a used four door Jeep Wrangler Rubicon.

As I researched more and more into the Wranglers I knew I wanted one with a little lift, 33" tires or larger, a winch and the locker/sway bar options provided by a Rubicon. I also like the color white and preferred to have a little older vehicle that I wouldn't be afraid of scratching.

After a month or so I found the one I wanted in Logan and a trip or two to the credit union I had my first Jeep — a white with black hard topped 2008 four door Jeep Wrangler Rubicon.

I absolutely love the Jeep however after a couple months of driving it I realized there was one thing that I hadn't researched about with running larger tires — axle gear ratios. The Jeep had 35" BFGoodrich KO2 35x12.5r18 tires which are really only have a 34" diameter when new. My 4 speed auto-transmission with the 3.8 L engine and stock 4.10 axle gears just didn't have enough power to use fourth gear. Unless I was driving downhill I had to turn the overdrive (4th gear) off. 

Weeks of studying gear ratio charts and talking with other Jeep owners I decided I better get the axle gears changed out. Wanting the jeep to last me for a very long time so I felt it best to get the gears changed over as soon as possible. I knew this had to be causing added stress to the transmission and engine by effectively only being able to use three gears of the transmission. I was running some higher than desired RPMs with only being able to use three gears instead of four.

The gear ratio I decided on was 5.13. This would take the gear ratio up three steps from the 4.10 stock gears that were in it. A lot of people tried to get me to go with the 4.88 gears but I really never felt this would offer enough power and I am so glad that I didn't get the 4.88 gears. One of the things I factored in in going with the 5.13 over the 4.88 is that my Jeep has really heavy Rock Slider bumpers and a heavy winch. I also carry a lot of heavy tools and a high lift jack. With the heavier equipment it further helped me decide to go with the lower gears.

I really like the 5.13 gears. I can travel up most interstates in forth gear even on climbs. Some of the steeper grades it does have to downshift to maintain 60+ mph.

If I could do it over again I would really like to try the next step lower 5.38 gears. 5.38 gears are the lowest gears you can fit in the Dana 44 axles that my JK Rubicon has front and back. One of the reasons I probably would prefer the 5.38 gears is when I get new tires. I'm not particularly fond of the KO2 tires I currently have. They are a good tire but I want a more aggressive mud terrain tread on my next set of tires. I'm looking close at the Nitto Trail Grappler Mud Terrain tires and from what I have been reading they are a true 35" tire thus lowering my RPMs from the 34" KO2 tires I am currently running. 

Another thing to keep in mind is that I use a Superchips programmer to get the tires size and axle gears correct. I actually have the tire size set for 33.75" to get the correct MPH using my phone's GPS to verify my speed.

After 500 miles or so of driving it was recommended to me to drain the gear oil and replace it with some new oil. After a bunch of studying on gear oils I chose to use Lucas 85W-140 Heavy Duty Gear Oil. Researching gear oils I found that synthetic gear oil did not transfer heat away from the gears as well as traditional oil so I went with this Lucas 85W-140 Heavy Duty Gear Oil over the synthetic 75w-140 that the owners manual recommends.

6mm Creedmoor Handloads and Ballistics

3 Shot 6mm Creedmoor group, 103 ELD-X

This 100 yard, 103 Gr ELD-X, 6mm Creedmoor group is exactly 1/2". It fits under a penny and almost under a dime. The third shot was the high one. I felt like I was a little high on the target when the trigger broke. Some might want better groups but this is perfectly fine for me.

Below are my personal favorite loads for my Browning X-Bolt rifle(s). To view the loads you will need to read the warning near the bottom of the page, then accept the warning by checking the box inside the warning.

So far the only bullet I have been playing with in my 6mm Creedmoor X-Bolt is the 103 Gr Hornady ELD-X. I've been really liking the ELD-X bullets from Hornady and have been moving more and more of my rifles over to these bullets.

If you are needing printable targets for sighting in your rifle you can get them here.

WARNING: The load information on this page is for my personal use in my personal firearms and is posted for entertainment purposes only. If you chose to reload the 6mm Creedmoor use only data contained in current manufacturer's reloading manuals. Incorrectly reloaded ammunition can cause serious personal injury and damage to the firearm due to excessive pressure. Reload only after proper instruction and in strict compliance with instruction and data contained in current manufacturer's reloading manuals. If you choose to use my load data on theDIYhunter.com you are doing so at your own risk. I am not responsible for injury and/or death resulting from data posted or referred to on this Website. Improper reloading is dangerous. Users assume all risk, responsibility, and liability for any and all injuries (including death), losses or damages to persons or property (including consequential damages), arising from the use of any data posted on this site. If you have read and accept this warning check this box to view my 6mm Creedmoor load data.

Elk Pack Out Made Easy With The e-Pack Wheel — 2018 General Elk Hunt

Elk Hunting with my boys

Dallen Elk Hunting with X-Bolt 300 WSM

Dallen with Spike Elk

Browning X-Bolt 300 WSM with Elk

e-Pack Wheel Elk Pack Out

Back to the Rubicon with the Elk on the e-Pack Wheel

This year I bought a combo elk tag hoping I would have time to get out and hunt elk again with my bow and for sure spend a few days hunting with my muzzleloader in November. 

The few times I was able to get out and check my trail cameras through the summer and into the fall I have noticed a very distinct change in the patterns of the elk in the area. The elk haven't been coming into the area nearly as much as they have in past years, not that there ever was a lot of elk but this year the cameras were showing a reduced number of elk.

There was one bright highlight to my trail camera footage and that was a nice looking six-point bull had been camped out in the area from July 23rd through August 5th. Unfortunately, he never returned but we sure hoped he would.

One bull and the only elk that was in the area during the hunting seasons was the Unicorn bull I had on camera last year. Funny thing is he was a unicorn again this year except he was a unicorn on his right side instead of his left. What a strange bull. How in the world did he get a unicorn G1 only rack again this year and on the opposite side?!?

Archery season came and went with me just not having the time to break away to get out and hunt at all. When rifle season came around it found me and my two youngest headed up the mountain for the opening weekend. We had a great time sleeping in the tent and enjoying a ride in my new to me 2008 Jeep Wrangler Rubicon I bought as a replacement for my old Montero. I had a great run with my old Montero but she finally gave up the ghost this summer.

We spent the opening Saturday watching deer but never saw any sign of any elk. We tried boys, we tried. So we checked a few cameras and back home for church we went.

Midweek Dallen took a few days off work to hunt. He hiked over into a different area than where I took the younger boys on opening day. He stayed out all day his first day out moving around in an area of thick oak brush and maples, hunting small meadows in the trees. As the day was coming to a close and he was about to get up to start hiking back out he turned around and a spike with some cows had snuck in right behind him. His occasional cow calling had worked at bringing in some elk. 

Dallen's X-Bolt 300 WSM put the spike down and he was quickly on the phone to me asking if he should also fill his cow tag and ask for me to hike in to help him with an e-Pack Wheel. I was in the process of helping my kids at home with their evening activities when the call came in. No don't shoot a cow, we'll have plenty to deal with getting the spike out this late in the day. Dallen could have taken a cow as well but I was glad he didn't. 

By the time I dropped off Landen at a football game and made it up the mountain to meet up with Dallen it was midnight. Not a good thing for me because I didn't sleep well the night before. Anyhow, needless to say, I wasn't feeling well but we worked into the night boning out his elk. It wasn't one of the fastest deboning processes I've done but we got it boned out sometime in the middle of the night and all loaded on the e-Pack Wheel for the muddy pack out up the side of a canyon and about a mile back to my Jeep.

The pack out was a total dream! We loaded the whole elk up on the e-Pack Wheel (150 lbs. of meat and near 20 lb head) and up the mountain we went through the mud. I learned a few things on this pack out to improve the e-Pack Wheel design. Mainly, I wanted to lower the Mud Cutter on the e-Pack Wheel to clean the tire from mud even better than it already did. We didn't have any problems with it but I felt it could use some adjustment to keep mud from getting into the chain. What an amazingly cool system to haul an elk out with and not carry an ounce of weight out on your body. The e-Pack Wheel carries to load up or downhill without you carrying any weight or any pushing/pulling at all. The electric motor is geared to have tons of torque to climb, climb, climb. I love it!

Nice work solo hunting Dallen. This was his first elk harvest being out hunting by himself. After this hunt I feel Dallen is ready to go totally solo on the boning and pack out all on his own. Especially if he has an e-Pack Wheel with him.

After a day I was back out with Landen and KB hoping to find some elk on the second Friday evening and Saturday. And.... once again Dad couldn't find a single elk for my youngest boys. And that finished the extent of my elk hunting this year.

Due to work demands this year I just wasn't able to get out and hunt with a muzzleloader for myself and the two Saturdays I was able to get out with my boys resulted in not finding any elk. I still loved spending time with Landen and KB but wished we could have seen some elk. Next year maybe and we all still have cow elk tags that go through January. 

Subcategories

  • Big Game Hunting

    Journal entries from hunting mule deer, elk and whitetail deer.  You'll find hunts with 243 WSSM and 270 WSM rifles to muzzleloader and archery hunts.

  • General Hunting and Shooting

    Journal entries covering general information related to hunting and shooting. Many of these journal entries are from shooting on the rifle or archery range. There are also entries related to my experiences with the 243 WSSM, rifles, optics and other equipment and products I use.

  • Varmint Hunting

    Journal entries from hunting coyotes, rock chucks, prairie dogs and the like with 243 WSSM and 223 Rem. rifles.

  • Backpacking and Camping

    Backpacking, Pack Wheel camping and other camping adventures.

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