YJ/TJ Wrangler Jeep ~ Cars and Bikes
Cars and Bikes

Thursday, 3 January 2008

YJ/TJ Wrangler Jeep

The YJ Wrangler (later become TJ and JK) is an off-road vehicle produced by American automaker Chrysler under its Jeep marque. It is a successor to the famous World War II 'Jeep' vehicle by way of the Willys Universal Jeep (CJ) in the 1950s, later produced by Kaiser-Jeep and AMC. The Wrangler debuted in 1987, was updated in 1997 and again in 2007, and is still popular today.

The Wrangler, 1987 to 1995 models were sold as YJ, and 1997 to 2006 models were sold as TJ. The model designations of YJ and TJ are used throughout the world in the Jeep enthusiast community to differentiate which model is being spoken of instead of using the more ambiguous term "Wrangler".

The Jeep YJ, sold as the Wrangler, replaced Jeep CJ in 1987. It was a new design with a wider wheelbase, slightly less ground clearance, a galvanized body and more comfort. The YJ also had a leaf spring suspension similar to that of the CJ, however, the springs were wider, and the YJs sported trackbars and swaybars for added handling. YJs are easily identifiable by their rectangular headlights, which were a source of controversy when introduced. Despite the new grill, the body is very similar to the CJ's, and it is interchangeable with some minor modifications.

The YJ used a 2.5 L AMC 150 I4 or optional 4.2 L AMC 258 I6 until 1991. That year, a fuel injected 180 hp (134 kW) 4.0 L AMC 242 variant replaced the 112 hp (84 kW) 4.2 L straight-6. The NP207 transfer case was used only in 1987 and replaced by the NP231

The roll cage was extended in 1992 to allow for rear shoulder belts, and anti-lock brakes were added as an option the next year. An automatic transmission option for 4-cylinder Wranglers came in 1994 along with a center high-mounted stop light.

In 1994, the slave cylinder on manual transmissions was moved outside of the transmission's bellhousing to allow for easier replacement, and in 1995 larger U-joints were used.

The review below is written by thermocouplerelay, I’m really impressed with his review, it is exactly represent the YJ/TJ Wrangler situation.

Wrangler Jeep, whether you buy a hardtop or a ragtop, you can take the top off drive down to the beach (right up to the surf), snake through fire roads to a secluded campsite, or just look darn cool in the high school parking lot--whether you're a teenager or not!. You can take your dog down to the river for a little swim, then have him jump in and not be concerned about messing up your weather-resistant seats. With the turning radius of a bulldozer, and being short and providing good visibility of its ends, it's also a great urban vehicle; you can parallel park in spots an SUV could only dream about. And let's not forget the ability to park in spots that normal people wouldn't even notice as a spot, like a muddy grass at a festival where they have you parking in a field.. And with real 4wd, not that awd stuff where the front and rear axles are not locked together, a foot of freshly fallen snow won't keep you from getting out to shovel your parents' driveway at the crack of dawn after a blizzard. For Southerners, after a hurricane washes sand across the highway, and in some cases the blacktop has eroded away, or tree branches litter the streets after a major storm, that won't stop you either. Of course you should never drive through flood water, but just in case you had to, Jeep designed the TJ (1997-2006 Wrangler) to wade through water up to the headlights.

Unfortunately there is a price to pay for driving such an incredibly uncompromising vehicle. It's noisy, and it bounces around. In old CJs and square-headlight Wranglers, it's so noisy at highway speeds you can barely talk to the person next to you. The hard top deadens the noise a little, but with big knobby tires and wind whipping around a flat windshield, it's no library. With that classic design comes a complete lack of aerodynamics, and that means poor gas mileage. The 97 up TJ Wrangler had the windshield swept back a bit more, but gas mileage is still well below 20mpg. With a ragtop, you can't lock anything inside unless you purchase an insta-trunk from Quadratec or the Jeep dealer. This will give you a small, maybe 3-4 cu ft enclosure to lock up some tools, a purse or other small items, creating a small trunk in front of the locking tailgate. Of course now you have lost most of the space in the back for when you want to carry things like bags of mulch, groceries, patio pavers, or large boxes. With the rear seat removed, there is actually quite a bit of cargo room, which is easily accessible by the swing-out tailgate. There is a locking center console and a locking glove box, but are plastic compartments ever truly locked? Best bet: get a hardtop. If you're buying used, the increased cost will be minimal. You can take the hard top off almost as easily as the soft top (just need to find a place to store it); you can lock stuff inside; and it will last the life of the vehicle. No matter how well you take care of them, the soft tops need to be replaced every few years ($500-800). The only drawback with a hardtop is that when you take it off you still have the full frame doors which look kind of goofy. Solution: pull the doors off. They're made to come off by pulling the two hinge pins. Just make sure you buy some mirror relocator brackets from Quadratec so you can mount them via the screws on the windshield; otherwise you might get a ticket (or worse, cut somebody off). And buy a $90 bikini top (piece of canvas that only covers the front seats and ties to the rear) to protect you when you inevitably get caught in the rain.

Upgrades from the CJ-7 (made by AMC) to the square-headlight Wrangler (designed by AMC but made by Chrysler--right after they bought the Jeep nameplate): new interior, with gauges arranged in a somewhat egronomic way, rather than just where they fit in the sheetmetal; new funky square headlights (which apparently only the guy who designed them thought was a good idea); and after a year or two, the old CJ-vintage 258 cu in (4.2L) straight six with a Carter 2bbl was replaced with a "high output" throttle-body injected 4.0L straight six. The 4.0L survived with only minor changes (multi-port injection in TJs) through the 2006 model. This year it has finally been retired in favor of a 3.8L V-6. The old faithful 4.0L was the premium engine in Wranglers and Cherokees and the base engine in 1st and 2nd gen Grand Cherokees.

Some of the upgrades from the square headlight Wrangler to the newer round-headlight TJ Wrangler include: (obviously) the old-school round headlights; leaf-springs replaced by coil springs for a better ride on and off-road; nicer interior with dual airbags; optional Dana 44 3/4 ton axles for serious off-roading (not necessary for 99% of the people who buy Jeeps); an easier to use framework system for the soft-top which keeps it tighter (quieter) and makes it easier to remove; room in the wheel wells for 31x10.50R15 (equal to 255/75R15) tires with the stock 7" wide rims (old Wrangler could only accept 235/75R15--two sizes smaller).

I highly discourage buying a 4 cyl. They are ridiculously underpowered, and get about the same mileage as the 6cyl. If you're that concerned about mileage, maybe Jeeps aren't for you. The combination of weight and drag from the four-wheel-drive system and aerodynamics of a brick make for very poor gas mileage. Great second or third vehicle; not so great primary commuter.

Though the Jeep 4.0L straight-six is among the most reliable engines ever to come out of Detroit, chances are, the exhaust manifold has or will go bad. You can tell this by a slight hissing sound when the engine is running, or when you accelerate while driving. Banks and Borla both make great stainless steel headers (a header is a tubular pipe that is the first part of the exhaust system leaving the engine head--when a cast iron grouping of pipes is used, it's called a manifold). It's not the kind of thing that will leave you stranded, and you generally notice it getting worse over a period of a few months--plenty of time to catch it.

What kind of tires do you want to put on your Jeep? If you buy a Jeep that originally had little little tires (225/75R15 or smaller), and you go out and buy wide aftermarket rims and 31" tires (Rubicon size), you'll probably find that it now accelerates like a dog and you can't use 5th gear or the engine will bog down. This is because your axles are geared at 3.07:1, which is not appropriate for larger (cool-looking) tires. You can tell what ratio it has by crawling on your belly and looking at a small steel tag on the back of the differential housing (that pumpkin-looking thing in the middle of the axle). Look for a 3.73 or higher if you want to put bigger tires on. Your best option is to get a TJ which came with the 30" tire option. A factory tow package should ensure you have an adequate gear ratio for up to 31" tires. Also, for some reason they usually gave Jeeps with automatic transmissions higher ratios, more appropriate for larger tires. Remember the final drive ratio has nothing to do with the transmission, it's the relationship of the number of teeth on the ring gear vs the pinion in the axle housings. The higher the final drive ratio the "lower" the gearing.

Now that you've bought your Jeep, go out and have some fun. You can contact your local forrestery dept to find out where you're allowed to drive off-road. There are actually open trails all over the place. If you drive on private land without permission you can be arrested for trespassing. And making a mess on trails you're permitted on will only ruin it for future wheelers. Off roading is about creeping through difficult terrain and driving up near-vertical cliffs (and hitting the occasional mud pit if it's designated for that purpose by its owner), not doing donuts in a cornfield. Keep it in 4 Lo when crawling over rocks or up super steep grades to avoid overloading the auto trans or manual clutch. It sounds cliche, but you really need to get out there and see what your Jeep can do--just once--to appreciate it. So many people buy Jeeps solely for the look and never venture off-road. That's like buying a plane and just taxiiing around the airport! That short-wheelbase, high-clearance design is not just for looks. You'll be grinning from ear to ear once you leave the pavement.

Final notes:
Good for kids, grown-ups with no kids, grown-ups with kids out of the house. Not good for grown-ups with multiple little kids. Our Yukon holds just a bit more than the little TJ it replaced. Beleve me, it was tough to sell a vehicle which had given me five good years and had absolutely no problems, just because we'd outgrown it. And it's even worse when that vehicle is an American icon that never gets old. I sure do miss her. A nine-year-old. It still looked and ran like brand new. I always wanted to buy some aluminum rims but never got around to it. I did get the ARB air locker installed after having it for two years. Looking back and comparing how many times I had to use it (5) vs the cost (about $2,000.00 when all was said and done), it was a colossal waste of money--$400 per use! But it sure was comforting to know it was back there when the going got tough. From now on, I'm buying trucks with the differential lock already installed!

No comments: