4120-04, 8009-1204

Synergy D30 / D44 Heavy Duty Front Ball Joint Sets

Part #: 8009-12X
Weight: 4 lbs
  • MSRP: $125.00
Purchase through our Dealer Network.
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Replace your Jeep's factory ball joints with Synergy MFG's NEW Dana 30/44 Heavy Duty Ball Joint Set. These ball joints employ a metal on metal design to improve durability and performance. A must for vehicles with lifts and larger tires. Get rid of that steering wander and play caused by loose or worn out ball joints.

Synergy MFG's New And Improved ball joints are the result of actions that have been taken to address reports of premature wear on the previous iteration Product changes and manufacturing changes have both been made to guarantee you are getting the highest quality ball joints on the market.


Part #YearMakeModelKnurledBall Joint Set
4120-041990-1992JeepComancheYes(1) Upper / (1) Lower
41201990-1992JeepComancheYes(2) Upper / (2) Lower
4120-041990-2001JeepCherokeeYes(1) Upper / (1) Lower
41201990-2001JeepCherokeeYes(2) Upper / (2) Lower
4120-041987-2006JeepWranglerYes(1) Upper / (1) Lower
(2) Upper / (2) Lower
4120-041993-1998JeepGrand CherokeeYes(1) Upper / (1) Lower
41201993-1998JeepGrand CherokeeYes(2) Upper / (2) Lower
8009-12041999-2004JeepGrand CherokeeYes(1) Upper / (1) Lower
8009-121999-2004JeepGrand CherokeeYes(2) Upper / (2) Lower
8009-122007-2018JeepJK WranglerYes
(2) Upper / (2) Lower
8009-12042007-2018JeepJK WranglerYes
(1) Upper / (1) Lower
8012-601999-2004JeepGrand CherokeeNo(2) Upper / (2) Lower
8012-60041999-2004JeepGrand CherokeeNo(1) Upper / (1) Lower
8012-602007-2018JeepJK WranglerNo(2) Upper / (2) Lower
8012-60042007-2018JeepJK WranglerNo(1) Upper / (1) Lower
4140-601990-1992JeepComancheNo(2) Upper / (2) Lower
4140-60041990-1992JeepComancheNo(1) Upper / (1) Lower
4140-601990-2001JeepCherokeeNo(2) Upper / (2) Lower
4140-60041990-2001JeepCherokeeNo(1) Upper / (1) Lower
4140-601990-2006JeepWranglerNo(2) Upper / (2) Lower
4140-60041990-2006JeepWranglerNo(1) Upper / (1) Lower
4140-601993-1998JeepGrand CherokeeNo(2) Upper / (2) Lower
4140-60041993-1998JeepGrand CherokeeNo(1) Upper / (1) Lower


  • Compatible with all aftermarket axle shafts (including RCV) with no modifications needed
  • Ball Joint bearing surface area is considerably larger than stock due to elimination of the inner nylon liner for a longer lasting joint


  • New and Improved Ball Joints - Part #'s 8009-1204 and 4120-04
  • Fully greasable metal on metal design for prolonged life
  • Ball joint housing is manufactured from sintered graphite, bronze, and 1045 steel for a strong, smooth, bearing surface
  • Ball joint stud is manufactured from induction heat treated 4140 steel for maximum strength and smooth operation
  • Ball joint dust boot is made from wear/tear resistant black nitro-butile rubber (NBR)
  • 12 Month Unlimited-Warranty (see warranty information)
  • Synergy High Performance Grease (4119) recommended


  • Metal on metal ball joints require a small break-in period of typically 100-500 miles to fully "seat" the bearing surfaces. During this time the steering may feel "sticky" or slow to "return to center". Once broken in, the steering will be smooth and tight.
  • Knurled ball joints required when replacing knurled ball joints that have enlarged the axle end forging bores
  • Non-Knurled ball joints recommended for replacing non-knurled ball joints
  • Due to these ball joints being tight tolerance, metal on metal ball joints, proper fitment is critical. Using the wrong style of ball joints can cause significant steering issues. We always recommend installing non-knurled ball joints until non-knurled ball joints are no longer a press fit into the axle end forging bores. If your axle end forging bores have been enlarged to the point that non-knurled ball joints are no longer a press fit, knurled ball joints are required.
  • Use of the improper ball joint style for the axle housing voids our warranty. It is up to the installer to verify the proper ball joint style is being used.
  • 8009-1201 ball joints have been superseded by 8009-1204
  • 4120-01 ball joints have been superseded by 4120-04
  • The zerk fitting is a 1/4-28 threaded hole  

*If you have older Synergy MFG 8009-1201 or 4120-01 ball joints that did not live up to your expectations, Synergy MFG has extended the warranty period for ball joints manufactured in 2016 and 2017 that experienced premature wear. Contact support@synergymfg.com for more info.

PPM-8009-12-Lower-Cutaway-400.jpgInstallation Instructions

Lower Ball Joint Cutaway Sample
PPM-8009-12-Cut-Away-400.224.jpgUpper Ball Joint Cutaway Sample

Synergy HD Ball Joints (above) vs. Mopar Factory Ball Joints (below)
Synergy HD Ball Joints feature a fully greasable sintered metal on bushing design that has high wear resistance. Outperforms the Mopar factory plastic bushing.

    • SKU
    • Weight
      2.74 lbs
  • Manufacturer
    Synergy Manufacturing
  • Part #
    8009-1204 (1) Upper / (1) Lower, 8009-12 (2) Upper / (2) Lower, 4120-04 (1) Upper / (1) Lower, 4120 (2) Upper / (2) Lower, 8012-60 (2) Upper / (2) Lower, 8012-6004 (1) Upper / (1) Lower, 4140-60 (2) Upper / (2) Lower, 4140-6004 (1) Upper / (1) Lower
  • Synergy High Performance Grease
    No, Yes [4119]

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