A buddy of ours that works for Jeep used to joke about the vehicles falling apart at 75,000 miles. We've also heard complaints about Jeep quality in the past. Much of it can be dismissed as owners not understanding it's a Jeep, not a car. Jeeps have some inherent audible noises and quirks. Anyway, we decided to keep track of the reliability our '01 Project TJ. And not only did we keep track of what went wrong with the factory parts, we kept an eye on the aftermarket ones as well.
We introduced Project Red in the January '02 issue ("Road Trip With Red, Part I") and built it up issue by issue until the March '03 issue ("Road Trip With Red, Part VIII"). Since then, we've put a total of 115,000 on- and off-road miles on Red, so we know what worked and what didn't. With 4 inches of lift and 35-inch tires, Red is a typically built TJ. Even though we've been slackers in the maintenance department, our TJ has held up pretty well. Oil changes and grease-gun intervals ranged from every 3,000-7,000 miles, but the tranny is still on its original oil. The front differential lube has nearly 100,000 miles on it and we're sure it needs to be changed, but the rear diff and the transfer case have actually seen a few oil changes. Ultimately, driving over the equipment's capability and abuse could have caused a lot more damage to our Jeep than our lack of maintenance, but here's the lowdown on what went wrong and right on Red.
Final story on Project Red goes to print. Rear Dana 44 ARB Air Locker has internal seal failure (inside differential, not installer error). We replaced it with a Detroit Electrac.
Rear passenger-side axle seal begins to leak. Pull shaft and silicone the outside of the seal surface to the housing. Leak fixed.
Installed a high-clearance skidplate and replaced the 4-inch lift coils with 3-inch. The rear driveshaft angle looks fine
Currie rear driveshaft begins making noise after a 1,700-mile road trip to Colorado at 75-plus mph in 100-plus degree heat. It turns out to be a wasted CV (looks blued and overheated). Replace with another Currie driveshaft (CE-97984).
HVAC fan quits working. Starts out as an inconsistent problem, but eventually stops working entirely. Heat and A/C still work, just no fan. Try replacing parts that Web wheelers recommend ($80 fan switch and heater resistor), and it doesn't fix the problem
Original front brakes finally wear out. Driver side is worn down to the metal. Installed new rotors and pads. Rear brakes have more than 50 percent remaining
Second wasted CV rear driveshaft. Replaced it with same Currie part number again and removed the high-clearance skidplate that was causing too much angularity. The Currie driveshaft has greaseable U-joints, but the CV is a sealed joint. A regularly lubed, greaseable unit would probably survive with a high-clearance skidplate and 3-4 inches of lift. Rear output seal on Currie slip-yoke eliminator kit leaking. Replace special Currie-only seal (CE-9069TS).
Rear Dana 44 Detroit Electrac not functioning properly and is making noises. Seems fine with the unit unlocked. We hardly need the locker anyway because the limited slip works well.95,000 MilesRear Detroit Electrac begins to bang and clunk, even when unlocked. Pull it to find it has eaten itself alive. Replace Electrac with the new version of Detroit Truetrac limited slip (new 50 percent stronger three-pinion design).
Summertime temps get out of control, so we focus on fixing the HVAC fan. Pull dash apart to find it's the HVAC switch itself. It looks slightly overheated and melted. Pull apart, clean, and lubricate switch. Air conditioning and heater fan works again!
Avenger Supercharger reaches 100,000-mile mark and begins to whine. Sounds like a bearing noise near the rear of the unit. Rear output seal on transfer case slip-yoke kit leaking again. Replace special Currie seal again (CE-9069TS).
115,000 MilesRadiator looking scaly inside and Jeep seems to run hot even though the gauge says it's OK at 215 degrees. Install flush-and-fill adapter in heater hose, flush out the system, and refill with fresh coolant. Still seems like it's running hot even though the gauge reads 210-215 degrees (normal)
Overall ImpressionsFor a vehicle that tackles off-road trails regularly and is used as a daily driver, our Wrangler has been extremely reliable. We're still on the original clutch, water pump, alternator, starter, and so on. Yes, the NV3550 tranny is noisy at idle, but it hasn't changed since day one. It's a truck transmission, and it's just one of the inherent quirks you have to live with if you own a Jeep. Hey, it's not a car and, thankfully, it will never perform like one
The Avenger Supercharger, although now beginning to show signs of wear, was definitely the best power mod we could have made to the 4.0L engine. We highly recommend an aftermarket intake tube and open-element air filter to get the full power benefits. The rest of the Jeep, including the exhaust system, is stock. We average 11-12 mpg on required premium unleaded fuel. On the highway and off-road, the supercharger complements the 4.56 axle gears and 35-inch tires. Had we not installed the supercharger, 4.88s would have been the gear of choice. Our Jeep isn't an extreme rockcrawler, but it has traversed the Rubicon Trail and been through Moab several times without issues. We have never wished for more gearing than the 2.72 low-range gearing in the NV231 transfer case.
Red currently sits on 35x12.50R16 Nitto Mud Grapplers on 16x8 wheels with 4.5 inches of backspacing. We used a combination of 1-inch body lift and 3 inches of suspension to clear them. The tires are a little wide and rub at full stuff and steering lock. The best-fitting tires we've ran were 315/75R16s on 16x8s with 4.5 inches of backspacing. They're still about 35 inches tall but slightly narrower.
Rust hasn't been a problem anywhere (hey, it's California, what did you expect?). However, like many older TJs the fender flares have faded to a hue close to battleship gray. The factory top is still in pretty good shape. All of the zippers work and there are no holes. Well, maybe a small one, but that was driver error. The windows on the soft top are a different story. They are pretty scratched at this point and are difficult to see out of night and day. Ironically, most of the damage was done during cleaning and washing the Jeep. Liberal and frequent use of a plastic window protectant would have been a good idea.
Although very minor, we did have problems with the latch mechanism on the center console. It required a certain forceful jiggling finesse that borderlined on abusive. It was freakin' hard to open. We lived with it for a while until we disassembled the latch mechanism, cleaned it, and greased the plastic sliding components. Now it works just like new.
Red will most likely go through some changes in future issues. The trails it sees don't require 35-inch tires, and we'd like to get better gas mileage from the 4.0L for daily commuting. The next step could be to turn our 100,000-miler into a sleeper with high-clearance skidplates and maybe smaller tires. But if you have a build idea that you'd like to see, send it in to Jp Magazine, Build it This Way, 6420 Wilshire Blvd., Suite 100, Los Angeles, CA 90048 or e-mail your build idea firstname.lastname@example.org.