4 WD Four by Four

The Wrangler TJ was first time introduced in 1997 after one year no production gap from its prodecessor YJ. This updated Wrangler featured a coil-spring suspension (based on that of the Jeep Grand Cherokee) for better ride and handling, and a return to the CJ's iconic round headlamps. A new dash modernized the cabin upon its debut, while dual front airbags and the option of antilock brakes made it safer, too. Of course, all the ingredients (such as generous ground clearance, skid plates and a crawl gear for the transfer case) that made the original CJ so capable off-road remained. The engine is the same 4.0 L AMC Straight-6 used in the Cherokee and Grand Cherokee. A 2.5 L AMC 150 Inline-4 motor was available on entry-level models until 2003 when the 2.4 L DOHC Neon 4-cylinder engine replaced it.

All Wranglers have part-time four-wheel-drive systems with two-speed transfer cases. This, plus the short overall length and minimal overhangs, gives the Wrangler an almost unstoppable nature off-road, but provides a somewhat bouncy ride on anything but smooth pavement. Axles on a standard Wrangler are Dana 35s, with a 3.07:1 ratio; the tall gearing works against the four-cylinder and the TJ's barn-door aerodynamics on the highway. The axle option is the locking Dana 44 with a 3.55:1 axle ratio, which promises better acceleration and off-road capability in four-low. (The '03 Rubicon model offers a pair of these locking axles as standard equipment, along with upgraded suspension.)

The TJ have saveral trims i.e: Base SE (2.5-liter, 120-hp inline-4), Sport (4.0-liter, 190-hp inline-6, fancy wheels and graphics) and Sahara (4.0-liter six, air-conditioning, upgraded upholstery, CD player) trims were offered initially. By 2003, the Wrangler "X" (slotted above the SE and featuring the inline-6) and "Rubicon" (featuring hard-core off-road stuff such as a super-low range in the transfer case, 31-inch tires and locking Dana axles front and rear) trims debuted. Transmission choices included a five-speed manual and three-speed automatic, the latter upgraded to a four-speed unit for 2003. The new-for-'03 2.4-liter DOHC four sourced from the Liberty SUV adds 27 horsepower compare to the previously 2.5 inline-4. This 2.4 liter engine is quite enough for hauling TJ body especially for city and light offroad driving.

In 2004, Jeep introduced the Wrangler Unlimited model; it still had only two doors, but a 10-inch wheelbase stretch provided a significant increase in rear legroom and cargo capacity. A Rubicon version of the Unlimited arrived the following year, and a six-speed manual gearbox replaced the five-speed.

The engines are nearly bullet proof, especially the 4 liters inline-6. The 4.0-liter throttle-body butterfly needs to be kept clean, as coking up will cause an air leak at idle--watch for fluttering idle speed, however if you regularly maintain the engine, there is almost no problem with the engine. My 1998 TJ has almost 100,000 miles on the odo, without any major problem with the engine. A typical service interval between tunes and fluid changes is 24,000-30,000 miles. Those manual transmissions should be serviced at 30,000-mile intervals in normal usage, more often if used heavily off-road. You should put more attention in the hoses, either power steering hose, automatic transmission cooler hose or engine cooling sytem hoses. By age, this rubber hosses start to torn, or leaking. Leaking in transmission oil cooler hoses can damage your entire automatic transmission system.

The Jeep Wrangler for its off-road agility and personality is superb but scorned the plastic side windows and fussy soft top. This TJ is good for commuter duty, considering the vehicle's loud and busy ride at freeway speeds. Gas mileage as always become a main issue in Jeep was mediocre, slightly better than Grand Cherokee, its about 1 liters for 6 km in the city and 1 liters for 8 to 9 km in freeway. The standard, non-Rubicon version of the Wrangler Unlimited had slightly better road manners, thanks to its longer wheelbase and revised suspension tuning. However the Rubicon version which is superb in off-road capability but simply too harsh and bouncy on the blacktop.

When you buy a TJ a bunch of accessories are waiting to follow, there are plenty and almost unlimited choice. However suspension modification and lifting the TJ should be done properly, otherwise a typical jeep problems like death wobble, unbalance drive shaft, cv joint damaged can occur any time. And the last, ...be ready, every eyes will following you, .......Wrangler TJ is so sexy.

See my other post about wrangler jeep in Cars and Bikes blog

The WJ Grand Cherokee released first time at 1999. WJs, which were virtually same as WGs, were of slightly unusual design. It’s coming with more rounded shape compare to its predecessor Grand Cherokee ZJ/ZG. They featured monocoque chassis in order to increase interior space and remain car-like but used live axles front and rear. This was done to maximize off road ability over an independent suspension.

Grand Cherokee earned the nickname “Wobbly Jeeps” because they A-frame rear, top suspension link, which over superb axle articulation, doesn’t locate the rear axle as well as other means, making the car wobble.

These models were fulltime 4WD and came with the option of Quadra Drive II 4WD traction system, which provide limited locking of the front and rear diffs. While the system worked well, it was no match for diff locks, so if you are buying a Grand for hard off-road use, avoid the Quadra Drive equipped version, as it’s hard to convert them to run lockers.

Because of their monocoque chassis and very short front and rear trailing arms, WJ/WGs don’t lend themshelves to extreme off-road modifications. These models benefit from simple mods like fitting swaybar disconnects, a 2 in lift and diff locks, which combine to make the Grand a pretty capable playmate.

Again, if you want a 4WD to use for hard core off-roading, it’s best to look elsewhere. While they have been modified to performed off road miracles, be prepared to fork out plenty to achieve this end. Aftermarket products are limited compared to TJ, XJ and ZJ, especially if you are living outside of US, even bullbars are only sold by few suppliers.

BUYING USED
Being luxury vehicles, and priced accordingly when new, most WJ/WGs were purchased by older, more sedate owners and were seldom modified. This means there are plenty of good examples floating about that haven’t set foot off-road.

Because of the complexity of these vehicles and their quirky faults, it is always advisable to take any prospective buys to a Jeep specialist for once-over. To help you choose a vehicle worthy of a second opinion, follow this step:

- Walk around the vehicle and take a long look at the body work in good daylight, checking for paint inconsistencies and misaligned panel gaps that indicates the Jeep after a crash.
- Open the doors and check that the woodgrain trim inserts aren’t starting to fall off. Check the electric front seat adjuster, as well as heated seat work, which are prone to failing.
- Inspect the CV joint in the front propshaft, this joint breaks without much effort when off roading. Some manufactures offer a uni-joint replacement kit, which prevents this happening again.

- Check of visual signs on both the front and real trailing arms. The Grand Cherokee’s unsusual oval-shaped bushes wear out by about 100,000 km. This is partly due to the very short trailing-arm length and bush design.
- Check the outer front axle seals aren’t leaking this will be evident by oil around this area

- Looks for leaks around the transfer-case output shaft seal.

- Inspect leaks from the inspection cover gasket on the front and rear diffs.
- Under the hood, first check for coolant leaks from the radiator, the leaks occur commonly between the aluminium radiator core and the plastic side tanks. It is very important that there are no coolant leaks, because if the V8 engine overheats, and plenty of them have been known to, the alloy heads expand and cause the steel valve seats to fall out, causing major and expensive engine damage.