Ultimate Adventure Jeep CJ-17: The UACJ

131 1012 Ultimate Adventure Jeep Cj 17 The Uacj Front Trail Shot

Péwé's Pile quickly grew from a derelict '76 CJ-7 to a rip-roaring, aluminum-bodied trail killer we've christened the CJ-17 for its plethora of rivets and Boeing B-17 bomber styling. The Jeep had to lead our squadron of 4x4s on the annual Ultimate Adventure (read about it on page 24), so we had to stuff some hearty parts underneath.

We've already discussed the Erod GM Performance Parts LS3 crate engine ("Erod Action," Sept. '10), which is smog compliant to swap into just about any 4x4. We also told you about the suspension (Oct. '10), and the Aqualu aluminum tub we bolted onto the original frame (Nov. '10). This month we'll take you to Dynatrac, where we built a set of axles capable of spinning 37-inch Goodyear tires with ease.

Ultimate Adventure Sponsors
Goodyear
www.goodyear.com
Presenter and official tires

Hi-Lift Jack Co.
800.233.2051
www.hi-lift.com
Official jack

Hobart Welders
800.626.9420
www.hobartwelders.com
Official welder

Warn Industries Inc.
800.543.9276
www.warn.com
Official winch

BDS Suspension Co.
517.279.2135
www.bds-suspension.com
Official suspension

Overkill Engineering
877.225.0243
www.overkilleng.com
Official body armor

Bubba Rope
877.499.8494
www.bubbarope.com
Official recovery rope

Daystar
800.595.7659
www.daystarweb.com
Official polyurethane products

We decided early on that we wanted a Dana 44-sized front axle and a Dana 60 rear, so we headed to Dynatrac for a discussion of what would work best for our Ultimate Adventure buildup. Specializing in Dana-style axles, Dynatrac released a new ProRock Dana 44 housing this past year, and we wanted one under the front of the Jeep. Dynatrac supplied us with a bare housing with just the tubes pressed in to lay out suspension link locations.
We decided early on that we wanted a Dana 44-sized front axle and a Dana 60 rear, so we he
Once the mount locations were determined we returned to Dynatrac, where they began assembling our axles. Dynatrac offers two ProRock 44 housings, one that uses the old-style Dana 44 parts and one that uses the new Jeep JK Dana 44 gears and lockers. We went with the JK version so we could upgrade to a special ARB Air Locker. The axletubes are 31/8 inches in diameter with a wall thickness of 1/2 inch.
Once the mount locations were determined we returned to Dynatrac, where they began assembl
Our front axle is a hybrid ProRock 44 with Dana 60-sized axleshafts and steering knuckles. We did this with that special ARB Air Locker we mentioned. It fits the JK Wrangler Dana 44 ring-and-pinion as well as the Dana 60 35-spline axleshafts. You could put this same locker and big axles in your stock JK housing for additional strength.
Our front axle is a hybrid ProRock 44 with Dana 60-sized axleshafts and steering knuckles.

The Dynatrac 35-spline axleshafts are made of chromoly for plenty of strength, and CTM U-joints have proven themselves in the past. We opted for a fresh set in our bomber's front axle. All these sexy parts are made in America.
The Dynatrac 35-spline axleshafts are made of chromoly for plenty of strength, and CTM U-j
Our rear axle is a high-pinion ProRock 60 stuffed with 5.13 gears and another ARB Air Locker. Dynatrac has plenty of experience installing these ARB diffs. Each selectable locker is tested to see that it holds air pressure upon final installation. Notice how the ProRock housings hug the ring gear and locker for optimal ground clearance.
Our rear axle is a high-pinion ProRock 60 stuffed with 5.13 gears and another ARB Air Lock
The Dynatrac crew is meticulous when assembling these axles. For example, great care is taken when assembling the front housing in a giant press to ensure that proper caster and pinion angle are attained. Our front was set to 7 degrees of positive caster, with the pinion 2 degrees up.
The Dynatrac crew is meticulous when assembling these axles. For example, great care is ta

Dynatrac also does a thorough job welding the axletubes and suspension link mounts. Dynatrac uses big rotating fixtures to help produce some beautiful welds.
Dynatrac also does a thorough job welding the axletubes and suspension link mounts. Dynatr
For simplicity and strength we went with a full-floating rear axle setup. First, spindles are pressed into the ProRock 60 axletubes. Then they are welded tight.
For simplicity and strength we went with a full-floating rear axle setup. First, spindles
Along with the spindles, brake caliper mounts are welded to the housing. Dynatrac has begun using the disc brakes from the Jeep J8 military JK variant, and since we were sticking with a 5-on-51/2 bolt pattern, we went that route. Note the integrated parking brakes.
Along with the spindles, brake caliper mounts are welded to the housing. Dynatrac has begu

On the front axle we used Dynatrac's Dana 60 knuckles, but to ensure years of trouble-free use (and abuse) we upgraded to a set of Dynatrac's ProSteer ball joints. These rebuildable joints are designed for more strength than standard ball joints and are available for many Dodge, Ford, and Jeep vehicles.
On the front axle we used Dynatrac's Dana 60 knuckles, but to ensure years of trouble-free
The goal of Ultimate Adventure is building a street-drivable yet trail-tough 4x4, and that's why we chose Dynatrac's DynaLoc selectable hubs for our front axle. These same hubs survived the abuse of a Cummins engine and 42-inch rubber on our UAJK build a few years back, so they should be fine with 400-plus horsepower and 37s. The unique design is such that if there is an unlikely failure, the hubs will go to the locked position, ensuring that you make it off the trail.
The goal of Ultimate Adventure is building a street-drivable yet trail-tough 4x4, and that
Our axles ended up being 67 inches wide from wheel mount surface to wheel mount surface, so we made up for that with Walker Evans beadlocks (more on them next month) with 61/4 inches of backspacing. This did require some slight grinding to the steering arms for clearance, but it kept the Jeep from getting extremely wide.
Our axles ended up being 67 inches wide from wheel mount surface to wheel mount surface, s

SOURCES
Poly Performance 245 Tank Farm Road Units L & M San Luis Obispo CA 93401 805-783-2060 www.polyperformance.com	PSC Motorsports 11468 FM 730 South Azle TX 76020 817-270-0102 www.pscmotorsports.com
ARB 4x4 Products 720 SW 34th Street Renton WA 98057 800-761-8192 http://www.arbusa.com	Dynatrac 7392 Count Circle Huntington Beach CA 92647 714-596-4461 www.dynatrac.com
Western Fabricators 9823 E Avenue Hesperia CA 92345 760-949-1441 www.westernfabricators.com	Powdercoating USA 440 Sherwood Road Paso Robles CA 93446 805-237-8886 www.powdercoatingusa.net
MasterCraft Safety 9335 Stevens Road Santee CA 92071 800-565-4042 www.mastercraftsafety.com	Walker Evans Racing P.O. Box 2469 Riverside CA 92516 888-933-7223 www.walkerevansracing.com
Aqualu 435 Neave Court Kelowna AK 888-765-6714 www.aqualu.com	CTM Racing N/A AK 760-450-0006 www.ctmracing.com
Poison Spyder Customs 47275 Twin Pines Rd. Banning CA 92220 951-849-5911 www.poisonspyder.com	Mercenary Off Road Sun Valley CA 91352 www.mercenaryoffroad.com
GM Performance Parts P.O. Box 33170 Detroit MI 48232 800-577-6888 www.gmperformanceparts.com