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| Introduction | Installation | Bushing upgrade |
| Link arm washers | Addco & OEM part #'s | Skid plate interference |
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| There is a dramatic difference in the size and weight between the rear factory bar and the Addco bar. The thicker bar provides nearly 700% more resistance than the factory bar. |
Understeer is the situation that most vehicles typically have off the showroom floor. What this means is the vehicle "pushes" through a curve. This is usually caused by having a factory installed front bar and either no rear bar or a very lightweight rear bar in comparison to the front bar. So, by adding a rear bar, most of the understeer will be eliminated.
Oversteer is most commonly characterized by the rear end 'spinning out'. With the addition of a heavier front bar, oversteer can be corrected.
Torque resistance of an anti-sway bar changes with the square of the cross sectional area. Therefore, even a small increase in diameter provides a major increase in anti-sway bar effectiveness. The 1" Addco bar, for example, provides nearly 700% greater resistance than the 9/16" factory bar. In comparison, stepping down to a 7/8" Addco bar lowers the resistance to 382% (if you are only going to upgrade the rear bar, Addco recommends the 7/8" bar).
The vehicle body cannot roll without pushing down on one end of the anti-sway bar and lifting on the other. As the midsection of the bar resists twisting, it limits the amount of body roll. This is what will keep your car flat through curves.
Installation
See the chart below for Addco part numbers.
NOTE: Redesigned fall 2003 to eliminate interference with fuel tank skid plate
*Important: If you are only going to upgrade the rear bar (and not the front), Addco recommends using part # 634 (7/8"). Some owners have found using a 1" Addco rear sway bar with a stock front sway bar causes the WJ to oversteer. Update: Some owners have reported that the washers were not needed.
Rear 7/8": Energy Suspension p/n 9.5158R
superseded by 52088739AD (1999-2004) 52088281AB (2003-2004)
The revised 30mm solid steel sway bar with bushings will directly swap/bolt up on 1999-2003 models that came with the 31.5mm hollow bar. WJ owners who have retrofitted 1999-2003 models with the stiffer 2004 bar report a noticeable improvement.
(2x bolt p/n 6503571) (2x bolt p/n 6502936) superseded by 52088738AD (1999-2004)
52088284AE (2003-2004)
(upper bolt p/n 6502473) (lower bolt p/n 6503726) (upper bolt p/n 6505353AA) (upper nut p/n 6502697) (lower bolt p/n 6502473) (bolt p/n 6503571)
UPDATE: As of around November 2003, Addco has released a newly designed rear sway bar for the WJ that eliminates the problem of the bar banging into the fuel tank skid plate. Early reports from a few people that have installed the new bar report that the redesign does indeed solve the problem.
On a small percentage WJ's that have the factory fuel tank skid plate, the Addco bar fits so close to the plate that the bar will 'clunk' against it while going over bumps. This seems to be more of a problem on 2002 and later Grand Cherokees perhaps due to vehicle component variances.
In order to try and solve the clunking problem, I bought some 1" inside diameter soft clear hose and put a piece on each side of the bar where it was making contact with the skid plate. I cut the hose pieces all the way across horizontally to fit them around each side of the bar and then held them in place with zip ties. The first time I tried it the banging noise was gone but it squeaked annoyingly (soft plastic against metal). So I added a tiny bit of grease on each hose to make it "slippery" and viola! All is quiet and no banging noises. However, the drawback is that the plastic hoses have to be "re-greased" often so this may not be such a great solution after all. Now that a redesigned bar has been released by Addco, the best "solution" is to buy the new bar.
One of the more common complaints among Grand Cherokee owners is the amount of sway and body roll that is present. Therefore, it is no secret that one of the first mods that GC enthusiasts perform is to upgrade the stock sway bars to heavy duty performance versions from Addco Manufacturing. Most owners elect to just do the rear upgrade, the difference in the cornering and handling is amazing. Body roll and jiggle is pretty much eliminated. The front bar upgrade offers some improvement in oversteer but the difference is not that noticeable.
Understeer
Oversteer
Sway bar torque resistance
Installation of the rear Addco bar is simple. Remove the 2 bracket bolts and the link arm nut from each side to remove the factory bar, and replace it with the Addco bar. This can be done in a half hour or less, and without jacking up the car or removing any wheels. Because most suspensions travel in an arc, the use of a lift or supporting the vehicle by the frame and allowing the wheels to hang can cause bar misalignment and installation difficulties. The suspension must be at static ride height for this installation.
Parts:
Addco sway bars: 1999-2004 Grand Cherokee WJ
Sway bar upgrade kit
(Includes bar and non-greasable standard urethane bushings. Connects to the same mounting points as the factory sway bar).
Rear: Addco p/n 684 (1") *
Front: Addco p/n 175 (1.25")
Link arm washers
1-1/4" washer with 3/4" inside diameter
Rear: 1 required for each side, may require two per side if the washers are thin. Washers should be of anti-rust material or can also be painted.
Front: none required Optional greasable bushings
Energy Suspension greasable bushings (with clamps)
Performance Polyurethane. Highly recommended upgrade from the Addco standard urethane bushings. Unique channel design and zerk fittings, allowing grease to flow to the inner bushing surfaces which prevents squeaking.
Rear 1": Energy Suspension p/n 9.5161G
(It's possible to make the Addco front bushings greaseable by drilling and tapping the stock metal bushing shells and adding grease fittings. You then drill a corresponding hole through the bushing for the grease to pass through)
Factory OEM sway bar replacement parts
Part
Rear P/N
Front P/N
Bar, sway
52088661 (1999)
52088281 (1999-2003)
(Vehicles Built Before Nov 07, 2002)
Note: 31.5mm diameter hollow
(Vehicles Built after Nov 07, 2002)
Note: 30mm diameter solid steel (running change near the end of the shortened 2003 model year)
Clamp, bushing (x2)
52087865AB (1999-2004)
52088285 (1999-2004)
Bushing (x2)
52088322 (1999)
52088284AD (1999-2003)
(Vehicles Built Before Nov 07, 2002)
31.5mm diameter
30mm diameter
(Vehicles Built after Nov 07, 2002)
Link arm (x2)
52088319AB (1999-2004)
52088283 (1999-2004)
Bracket, link (x1)
52088525AC (1999-2004)
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Suspension Squeak/Squawk - Front Stabilizer Bar Bushings - A TSB was issued for this symptom in May of 2004, cover all Grand Cherokee WJ models 1999-2004. Here is a link to a PDF copy of the bulletin: TSB 02-002-04 REV. A
Fuel tank skid plate interference
