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This page last updated: March 31, 2016

WJ Addco sway bars upgrade

Introduction Installation Bushing upgrade
Link arm washers Addco & OEM part #'s Skid plate interference

Sway bars

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.

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 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.

Sway bar torque resistance

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.


Addco rear sway bar detail

Rear sway bar components shown installed on a WJ

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.

See the chart below for Addco part numbers.

Adding link arm washers (rear bar)

Due to the protusion on the factory link arm bolt, it is recommended to add a 1-1/4" washer (3/4" inside diameter) to each side, as shown in the photo above. This will prevent excess movement of the bar. These washers are not included with the Addco kits and must be purchased at a local screw/bolt specialty store. Update: Some owners have reported that the washers were not needed.

Bushing upgrade

Energy greasable bushing set

Energy Suspension greasable bushing and clamp set for the rear sway bar.  (1" version shown).

Many owners upgrade the Addco bushings supplied with the rear bar. Energy Suspension makes a set with a unique channel design and zerk fittings, allowing grease to flow to the inner bushing surfaces which prevents squeaking. The Addco supplied urethane bushings that come with the front bars are quite soft and tend to squeak. There are no aftermarket bushings available for the front bars due to the nonstandard bushing design of the front factory bushings. 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.


Addco sway bars: 1999-2004 Grand Cherokee WJ

Addco website - sway bar part numbers for all Jeep models

Sway bar upgrade kit
(Includes bar and non-greasable standard urethane bushings. Connects to the same mounting points as the factory sway bar).

NOTE: Redesigned fall 2003 to eliminate interference with fuel tank skid plate

Rear: Addco p/n 684 (1") *

*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.

Front: Addco p/n 175 (1.25")
Link arm washers
1-1/4" washer with 3/4" inside diameter

Update: Some owners have reported that the washers were not needed.

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

(manufactured by Energy Suspension)
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

Rear 7/8":  Energy Suspension p/n 9.5158R

Front: N/A

(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

Rear sway bar
Front sway bar
The Addco upgrade for the rear or front involves replacing items 1,2 & 3

Part Rear P/N Front P/N
Bar, sway 52088661 (1999)

superseded by

52088739AD (1999-2004)

52088281 (1999-2003)
(Vehicles Built Before Nov 07, 2002)
Note: 31.5mm diameter hollow

52088281AB (2003-2004)
(Vehicles Built after Nov 07, 2002)
Note: 30mm diameter solid steel (running change near the end of the shortened 2003 model year)

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.

Clamp, bushing (x2) 52087865AB (1999-2004)

(2x bolt p/n 6503571)

52088285 (1999-2004)

(2x bolt p/n 6502936)

Bushing (x2) 52088322  (1999)

superseded by

52088738AD (1999-2004)

52088284AD (1999-2003)
(Vehicles Built Before Nov 07, 2002)
31.5mm diameter

52088284AE (2003-2004)
30mm diameter
(Vehicles Built after Nov 07, 2002)

Link arm (x2) 52088319AB  (1999-2004)

(upper bolt p/n 6502473)

(lower bolt p/n 6503726)

52088283 (1999-2004)

(upper bolt p/n 6505353AA)

(upper nut p/n 6502697)

(lower bolt p/n 6502473)

Bracket, link (x1) 52088525AC (1999-2004)

(bolt p/n 6503571)


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

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.

Sway bars

Detail showing installation and location of rubber hose onto sway bar

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