• JP Magazine
  • Dirt Sports + Off-Road
  • 4-Wheel & Off-Road
  • Four Wheeler

Jeep Wrangler TJ: Weak Links, Strong Fixes

Posted in How To on August 1, 2010 Comment (0)
Share this

The Jeep Wrangler TJ is a great vehicle. When it debuted in 1997, it boasted a lengthy list of improvements over its predecessor the Wrangler YJ, and it had the effect of a lightning strike on the off-highway community. The TJ was a screaming success and its production run lasted through 2006. During that time, the wildly popular Rubicon model and the longer wheelbase TJ Unlimited (known unofficially as the LJ) were added to the roster. Even today, the TJ is one of the most popular choices for those wanting a solid, mega-capable off-highway vehicle.

The TJ is not perfect-some of the TJ's quirks are design flaws and some are issues due to the effects of aging and/or trail use. In this installment of "Weak Links, Strong Fixes," we identify some of the possible issues that can face TJ owners and offer suggestions as to how to fix 'em.

Soft Serve
Weak link: Factory soft top
Models affected: All
What happens: The fabric soft top on the TJ is a very durable unit overall, but time, UV radiation, and wind all combine to wear out the fabric and the plastic windows. Trail damage is by far a soft top's worst enemy. Nothing good ever comes of dragging a soft top along a tree or rock.

Strong fix: A variety of aftermarket tops are available, including those from Bestop. If your hardware is in good shape, you can simply install a Replace-a-top in standard or thicker sailcloth versions. If you need a new top and new hardware, they offer the Supertop in both standard and sailcloth versions. They also offer the Sunrider (with fold-back sunroof), Trektop (with easy roll back canopy), and Halftop (Bikini Windjammer and Duster Deck Cover for '97-'02 models).
Contact: Bestop, 800/845-3567, www.bestop.com

Tight Hinges
Weak link: Rear cargo door hinges
Models affected: All
What happens: The Jeep TJ's cargo door hinge assemblies are made from aluminum and they're fitted with steel hinge pins. These two dissimilar metals don't play well together. Over time the hinges get very stiff, which often requires a significant amount of effort to open and close the cargo door.

Strong fix: The hinges aren't greasable, so they must be replaced. You can get new ones from your local Jeep dealer or, if you have a '97-'03 model TJ, you can get 'em from Quadratec.
Contact: Quadratec, 800/745-2348, www.quadratec.com

Bad Vibes
Weak link: Short rear driveshaft
Models affected: All TJ (excluding LJ)
What happens: From the factory, the TJ rear driveshaft is very short. This is due to the short wheelbase of the TJ and a long drivetrain. When you install a lifted suspension under your TJ, the operating angle of the short rear 'shaft is increased, which leads to an annoying vibration. This vibration can ultimately cause things like U-joints to wear out at a faster rate. We've actually had rear driveline vibration on a stock-height TJ and it was amplified immensely just by installing a 2-inch coil spring spacer lift.

Strong fix: The problem can be alleviated by installing transfer case spacers to lower the transfer case and decrease the rear driveline angle, but this comes at a cost of ground clearance. The hot ticket is to install a slip yoke eliminator (SYE) kit. This will shorten the length of the NP231 transfer case, allowing the installation of a longer driveshaft and thus eliminating vibration. As its name implies, the kit also eliminates the slip yoke used from the factory, which means if your rig suffers trail damage and you have to remove the rear driveshaft, you won't lose fluid out of the transfer case. Further, many of these kits significantly upgrade the output shaft as compared to stock. There are many SYE kits available on the market. JB Conversions offers standard SYE kits as well as their HD Super Short SYE kit (shown). The Super Short is an additional 3.125 inches shorter than other SYE kits on the market.
Contact: JB Conversions, 337/625-2379, www.jbconversions.com

Housing Crisis
Weak link: Front axle
Models affected: All
What happens:
Two front axles were used under the TJ. All non-Rubicon TJs got the Dana 30 and Rubicon-equipped rigs got the Dana 44. When either of these axles are fit with 35-inch-and-up-diameter tires and subjected to moderate-to-hard trail use, the axletubes can bend at the differential and the inner "C"s can bend as well. This problem is similar to the one found in the wider JK Dana 30 and Dana 44 axles that we covered in the story "Support Group," page 66 (Mar. '09). The bent components can cause the front tires to tilt inward at the top (negative camber) and there can be gaps between the ball joints.

Strong fix: These housings are expensive, so the best course of action is to stop the damage from happening before it starts. Off Road Evolution and Burnsville Off Road are a couple of companies that offer kits to strengthen these axles. Pictured here are the EVO Magnum sleeves from Off Road Evolution. They install inside the factory axletubes to increase strength by 30 percent and they include dual seals to keep dirt and debris out of the axletubes. Off Road Evolution also offers axle gussets to reinforce the "C"s.
Contact: Off Road Evolution, 714/870-5515, www.offroadevolution.com; Burnsville Off Road, 952/890-3990, www.burnsvilleoffroad.com

Weak Axle
Weak link: Dana 35C rear axle
Models affected: All, as equipped
What happens: The Dana 35C is a notorious axle. It's relatively reliable for stock use on the street, but its fragility becomes quite apparent when you add larger tires and hit the trail. It's not unusual for the housing to bend, the differential to grenade, or the axleshafts to break-sometimes all at the same time.

Strong fix: Swapping in a beefier Dana 44 or Ford 8.8 axle is common. With one of these installed you can typically ply the rough stuff with up to 35-inch tires. If you've formed some sort of bond with your Dana 35C and can't bear to let it go, many aftermarket companies offer products to beef the 35C. Randy's Ring & Pinion offers the Ultimate 35 kit which includes two Yukon heavy-duty alloy 30-spline axleshafts, carrier bearings, studs, axle bearings, and shims. You can choose between an array of lockers, including their Yukon Grizzly Locker or their Zip Locker.
Contact: Randy's Ring & Pinion, 866/631-0196, www.ringpinion.com

Chill Out, Power Up
Weak link: Mechanical fan
Models affected: All 4.0L-equipped vehicles
What happens: The mechanical fan on 4.0L-equipped TJs sucks power from the engine, decreasing performance and fuel economy.

Strong fix: Swap to an electric fan. There are numerous options available, but Dan McKeag at Burnsville Off Road says they routinely swap out the mechanical fan for the electric fan used on '03-up, four-cylinder-equipped TJs. McKeag says it's a large unit that bolts in and helps the engine produce about 15 more horsepower. When Burnsville does these swaps, they utilize a Derale Performance adjustable fan controller with thread-in probe (shown). This controller has a maximum capacity of 25 amps, an adjustable fan activation range from 150 degrees to 240 degrees F, and a heavy-duty relay.
Contact: Burnsville Off Road, 952/890-3990, www.burnsvilleoffroad.com; Derale Performance, www.derale.com

Corrosion Is Closer Than It Appears
Weak link: Outside rear view mirrors
Models affected: '97-'02
What happens: The base of the factory outside rear view mirrors is made of pot metal and corrodes easily. We know, because we purchased a '97 TJ new and ours corroded after just one Midwest winter. While the corrosion doesn't seem to have an effect on structural integrity, it looks awful.

Strong fix: In '03, Jeep switched to non-corroding plastic molded outside rear view mirrors. They are a direct bolt-on and can be ordered through a Jeep dealer or found at a salvage yard.
Contact: Do-it-yourself fix

Search and Seizure

Weak link: Front driveshaft
Models affected: All
What happens: TJs came from the factory with a non-greasable front CV joint in the front driveshaft. Over time, these joints can dry out and eventually seize. When they seize, they can cause damage to the transfer case. "We've actually seen them split the transfer case in half when the CV seizes up," says Dan McKeag at Burnsville Off Road.

Strong fix: Needlessly wasting a transfer case is not cool, and it's rather expensive, so the best plan is to have a new driveshaft made that includes a greasable CV joint. Tom Wood's Custom Driveshafts or Driveshaft Superstore can hook you up.
Contact: Tom Wood's Custom Driveshafts, 877/497-4238, www.4xshaft.com or Driveshaftsuperstore.com, 800/845-6326, www.driveshaftsuperstore.com

Double Down
Weak link: Double shifter boot
Models affected: '97-'99 w/manual transmission
What happens: Here's another one we've experienced. These TJs use a lower and upper shifter boot and the combined resistance makes moving the transmission shift lever difficult, especially in cold weather. Most often, the problem is found when shifting from First to Second and Third to Fourth gears. Burnsville Off Road says they've seen transmission synchros damaged because the transmissions are used with gears not fully engaged due to the resistance. Sometimes the stiff shifting is misdiagnosed as a faulty AX-15 transmission.

Strong fix: The top shifter boot can be removed, which decreases resistance and alleviates the problem, but it's not aesthetically pleasing. A better method to free up the shifter is to make a small 1/8-inch cut in the lower boot near the shift lever.
Contact: Do-it-yourself

Loud Links
Weak link: Front sway bar end links
Models affected: All
What happens: The sway bar end links are a ball-and-socket type that quickly wear out, allowing the ball to bang against the socket. If you've been driving around wondering why there's a cacophony of rattling emanating from under the front of your rig, this could be the problem. We've had experience with this, too. Ours began to rattle with only 12,000 miles on the odometer.

Strong fix: Don't bother replacing them with stock end links, because they'll wear out as well. It's far better to install a set of aftermarket quick disconnect end links. Not only will they hold up better, you'll have the ability to quickly disconnect the front sway bar to allow for more suspension travel. There are many quick disconnects available in the aftermarket. Rough Country offers some that feature a 90-degree spherical ball joint for a full range of motion. They are designed to be simply folded up securely when on the trail and they fit TJs with up to 3 inches of lift.
Contact: Rough Country Suspension, 800/222-7023, www.roughcountry.com

Leaky Exhaust Manifold
Weak link: Exhaust manifold
Models affected: '97-'06 TJ w/4.0L engine, '97-'02 w/2.5L engine
What happens: If your exhaust manifold hasn't cracked yet, it will. You can count on it as much as you can count on tax time.

Strong fix: Swap on an aftermarket exhaust manifold assembly. We've installed the Borla unit; the header is constructed of T-304 stainless and includes a new gasket and all associated hardware. The folks over at Banks make a cool TorqueTube system for both the 4.0L and the 2.5L and each is a well-built, easy-to-install system that comes with everything needed to perform the swap.
Contact: Banks Power, 800/601-8072, www.bankspower.com; Borla Performance Industries, 877/462-6752, www.borla.com

About This Series
"Weak Links, Strong Fixes" is a series that identifies common problems of popular four-wheel-drive vehicles and offers solutions as to how to fix 'em. Past installments have included various Chevy, Ford, Dodge, Jeep, and Toyota vehicles.

Weak Retaining Straps
Weak link: U-joint retaining straps
Models affected: All TJ
What happens: Light-duty straps are used to mount both the front and rear driveshafts to their respective axles. They're fine for street use, but become a weak link on the trail.

Strong fix: Peace of mind comes with swapping in yokes with stronger U-bolt-style mounts. Randy's Ring & Pinion offers everything you need to do this swap. The new yoke is a Dana 44 unit with conversion seal.
Contact: Randy's Ring & Pinion, 866/631-0196, www.ringpinion.com

Cable Guy
Weak link: Seat pull straps
Models affected: '97-'99 TJ
What happens: Cables are integrated into each front seatback. These cables allow you to tilt the seatback forward in order to access the rear seat area without reaching behind the front seats to use the low-mounted levers. You simply pull on the exposed tab to release the seatback. Unfortunately these cables have plastic ends that break, rendering the system useless.

Strong fix: Wish we had better news, but when these cables break, you have to order the parts from your local Jeep dealer, remove the seats, and disassemble them to get to the broken cable.
Contact: Your local Jeep dealer

Unresponsive Knobs
Weak link: Climate control knobs
Models affected: '00-'02 TJ
What happens: In '00, Jeep introduced the twist-style climate control knobs which replaced the sliding-style controls used previously. The twist-style knobs are a unitized assembly and they have a high failure rate. Complaints typically revolve around unresponsive or partially unresponsive operation.

Strong fix: Burnsville Off Road says they've replaced scores of these knobs for customers. Unfortunately, there is no aftermarket availability for these parts and they must be purchased from your local Jeep dealer.
Contact: Your local Jeep dealer

Comments

Connect With Us

Newsletter Sign Up

Subscribe to the Magazine

Sponsored Content