This article begins a series titled "Project Triple Duty" where we will take a 1999 Grand Cherokee and outfit it to operate well in three distinct environments: Daily Commuter, Moderate Trail Runner and Cross Country Tow Vehicle. Can one vehicle perform well in all three environments? What modifications can be made to enhance performance in one area with out substantially detracting from another? How will it perform in real world tests? These are a few of the questions we will be seeking to answer as this series unfolds.

The first step was to purchase the vehicle and evaluate it on its own merits. We chose a 1999 Grand Cherokee (WJ) Limited with the 4.7 V8, Quadra Drive and factory Class IV tow package (rated at 6500 lbs.). These vehicles are plentiful and can be purchased for $10,000-$25,000 depending on mileage and equipment. The WJ is large enough to haul the family around, tow a large pop-up tent camper and yet nimble enough to maneuver in the outback or commuter traffic. If you plan to drive moderate trails, you may want to look for one with the Up Country package. This package provides heavier duty springs/shocks, tow hooks and skid plates. Our test vehicle is equipped with the basic suspension and does not have the skid plates or tow hooks; therefore aftermarket equipment will need to be installed. Project Triple Duty?s original tires were replaced just before we purchased the WJ with Delta Serriadial A/S (appear to be a knock-off of the Michelin LTX M/S) in the original equipment size. They will have to do for now as there is little room to increase tire size with the stock suspension and even less room to carry a larger full size spare.

Daily Commuter

The 4.7 easily pushes the stock WJ around during our daily 50 mile round trip commute. The Limited?s amenities are nice with the heated seats coming in handy in the winter and the steering wheel mounted radio controls allowing even the most fervent channel flipper to keep their attention on the road. The stock suspension is fine when cruising on the straight away, but push the WJ into a corner and she leans quite a bit. Our initial fuel economy ranged from 16-17 mpg, which is about average for a daily commute in a modern SUV. Figuring we could do a little better and enjoying the sound of a V8 engine, we replaced the stock air cleaner with a permanent Airaid oil/cloth filter. The installation took about 15 minutes and we will never need to purchase another filter. Interior noise increased slightly, but it does not exhibit any irritating whine. Next, we asked a local shop to perform a fuel injection cleaning, change all the fluids to synthetic and install a Flowmaster 70 Series three-chamber muffler. The Flowmaster sounds great and allows you to hear the exhaust note with the windows down. With the windows up at highway speeds, you do not get an annoying resonance like you do with a cheap turbo muffler. Daily commute fuel economy increased to 17.7-19.2 MPG following these modifications. As a daily commuter, the slightly modified WJ provides ample power, acceptable economy, amenities aplenty and a rather soft riding suspension. Next month, we will replace the stock shock absorbers to further enhance performance in this medium.

Moderate Trail Runner

Jeep marketing uses terms like "Rubicon Tested" and "Trail Rated" to describe their vehicles. Therefore, the WJ should be able to run moderate trails without?OK?with minimal chance of damage. A quick inspection of Project Triple Duty revealed these monikers may apply to WJ?s with the Up Country package, but the stock units are missing protective equipment needed to prevent damage during even mild off-road adventures. All WJ?s receive a gas tank skid plate of sorts, but everything else is just hanging out exposed to damage from rocks and other obstacles.

Take a look at the accompanying photo of the aluminum transfer case. It looks like a big expensive egg just waiting to be cracked on a rock. The Up Country package would have provided coverage of this critical system in addition to a skid plate up front protecting the radiator and a thicker gas tank skid plate. Fortunately, you can purchase these easy to install and inexpensive factory skid plates.

A quick web search took us to Mopar?s parts page where factory skid plate packages can be purchased and delivered to a dealership near you. To test the system, we ordered the transfer case skid plate kit (part #82204489 for $49) and front radiator skid plate kit (part #82207487 for $49). We were pleasantly surprised when our neighborhood dealership called in three days and said our parts were in. The parts manager looked at the price and asked how we ordered them giving us the impression he was not happy about not getting a cut of the action. We quickly paid, grabbed the parts and headed for the door.

The factory skid plates are well designed, inexpensive and aftermarket plates are currently not available. The transfer case skid plate installation was super simple. The kit provided a special rivnut installation tool and mounting hardware to attach the plate to the uni-body and cross member. Be careful not to over torque the bolts after the rivnuts are installed. The idea is to compress the rivnut in place with the special tool then carefully torque the mounting bolts down. Too much torque and you run the risk of stripping the rivnut loose from the uni-body.

Next we installed the front skid plate, which replaces the basic plastic splash shield. The splash shield is held in place with plastic fastener that are pushed into the factory installed rivnut. Using our handy trim removal tool, we pried the plastic fasteners out and removed the splash shield. The skid plate tucked in behind the plastic bumper cover and was attached with four 15mm bolts provided in the kit (Hint: Applying anti seize compound to all bolts during installation will reduce stress on the rivnuts if future removal is required.). The bolts are accessible through the bumper air dam and access holes in the skid plate although there is not a lot of room to use a socket wrench. We opted to use an air ratchet, which made quick work of the installation.

With the transfer case and radiator protected, we took the WJ on its first trail adventure. Sure enough, a few minutes into the trail we drug the transfer case across a rock ledge. The scratches on the skid plate indicate our $49 was well spent. We also confirmed all-season tires might work well on pavement, but have no place on the trail. They quickly filled with mud and prevented the 4.7?s power from reaching traction. Better tires are needed for moderate trail running. Naturally, we will want to increase tire size at the same time necessitating a lift of some sort. Watch for these modifications in future articles.

Cross Country Tow Vehicle

The ability to safely tow a 2001 Coleman Niagara folding camper on weeklong excursions across the country, unhitch and explore trails then drive back home is an aggressive goal for any SUV. The Niagara is equipped with electric 
brakes and weighs about 3700 pounds when fully loaded. Our 1999 WJ with the 4.7 V8 and Class IV towing package is rated to tow 6500 pounds, so towing the Niagara should be no problem.

The owner?s manual describes proper equipment and procedures for towing. The Class IV tow package includes many key components such as a weight distributing frame mounted hitch, auxiliary transmission cooler, heavy-duty radiator and 3.73 axle ratios with synthetic fluid. The manual indicates you are required to have trailer brakes when towing over 2,000 pounds and the Class III and IV towing package includes the necessary wiring to install an electric brake 
controller. We chose a Tekonsha Voyager electric brake 
controller and quickly found the blue wire above the brake pedal to tap for brake activation. Later model WJ?s come with a quick connector making it even easier to install a controller.

With these components installed, we hit the road for our first cross-country test from Oklahoma City to the Grand Canyon. With the WJ and trailer loaded, the 4.7 pulled the trailer on flats with little problem although, as the manual advises, you will need to disengage the overdrive via the switch on the
 transmission shifter when encountering even slight grades. 
Going west, we experienced a head wind rendering overdrive useless in order to maintain highway speed. This decreased fuel economy to 9 MPG. On the return trip, the wind was to our back and we were able to utilize the overdrive more often improving fuel economy to 14 MPG.

The WJ/Niagara combination seemed to be working well, and then it happened. On a slight down hill section of highway an 18-wheeler passed us and the trailer began to sway left and right. Applying the brakes aggravated the situation causing the entire vehicle to pitch violently. With the emergency flashers going, we let off the gas and allowed the rig to slowly decelerate and work its way out of the oscillation. The manual says sway control may be required. In our opinion, it should read, "Is required." We pulled off at the next exit with a RV service center and had a Draw-Tite sway control installed. This simple friction brake made all the difference in the world. The rig handles better and sway is nearly non-existent. We cannot stress enough the value of adding this piece of equipment. Aside from learning a lesson about sway control, this trip left us yearning for lower gears and a tighter suspension to improve performance in the towing environment.

Check out future articles where we will address these issues while seeking to improve performance in the daily commute and trail running environments.