Part 16: Axle Beef And Bigger Meats
A couple of months before Easter Jeep Safari, we started planning the next phase of Project 'Con Artist. We loved what we had accomplished so far-proving that a daily driven Unlimited JK on 35s could drive to the Rubicon, complete it, and drive home. In fact, we did it twice.
With that demonstrated, we decided we would finally bump up to 37-inch tires for less wear and tear on the 'Con and less fatigue and stress for the driver on those really technical trails. We settled on the BFGoodrich KM2 due to its proven trail reputation, excellent highway manners, and smooth, quiet ride. And of course our decision to increase tire size meant we had to make sure the rest of the vehicle was beefed up accordingly.
The first upgrade we decided to go with was 5.13 gears from G2 Axle and Gear. These gears put the engine RPM in nearly the same range as the 4.88s with the 35s that we have been running. Next, we decided to strengthen up our frontend and ditch the bent stock housing for a super-strong Dynatrac ProRock 44 housing.
The ProRock 44 is an all-new axlehousing that is designed from the ground up and comes with thicker axletubes, stronger end forgings, and offers the highest ground clearance of any Dana 44 axle. For TJ and JK applications, Dynatrac already has the brackets in place, making the axle a direct replacement. Because the ProRock 44 is available as a raw or empty housing, it allows you to transfer over all of the guts and wheel ends from your current stock housing or upgrade them as needed.
While we were busy swapping the front housing and gears, we also replaced the factory 30-spline front axleshafts with 4340 chrome-moly Discovery Series shafts from Superior Axle & Gear. This is a nice complement to the 35-spline Superior axle conversion that we were already running in the rear axle.
Another upgrade that we included was Reid Racing's heavy-duty JK knuckles. These direct replacement ductile iron knuckles have additional ribbing for strength and raise the tie rod 1.5-inches to minimize trail vulnerability. The Reid Racing parts maintain proper steering geometry on common lift heights of 3 to 4 inches by flipping the drag link.
While the front end was apart, we removed the Light Racing JounceShocks and had them rebuilt and retuned. Light did a great job going over the JounceShocks and returned them good as new, but with much more compliance, making for an improved ride over harsh terrain.
In last month's issue (July '10, pg. 72) we covered the addition of Bilstein's new 5160 remote-reservoir shocks, which have made a noticeable difference in the ride quality of our JK. In addition to the new Bilstein shocks, we also installed Bilstein's new monotube steering stabilizer.
Lastly, we gave our Rubicon Express Long Arm kit a thorough going over. We replaced tired bushings and lubricated and inspected each of the Rubicon Express Superflex joints.
We owe a big thank you to the hard-working crew at Off Road Evolution in Fullerton, California, who made time for us during the extremely busy rush leading up to Moab Easter Jeep Safari. Check out all of our upgrades in photos below.
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