Spherical Bearings

Automotive manufacturers must trade ultimate performance for comfort, reduced NVH (Noise, Vibration and Harshness) and drivability in varying conditions. They must also accommodate a range of driver skill levels and keep required maintenance and replacement to an absolute minimum. Thus, stock rubber/steel suspension bushings are quite adequate for a street driven vehicle. However, on a dedicated road race car the limitations and drawbacks of stock bushings are quite evident. The deflection inherent in rubber bushings and the large amount of breakaway torque required to articulate the suspension are detrimental to on track performance.

Installing control arms equipped with Kingpin Machine spherical bearings provides a number of benefits:

  • Lack of deflection allows reduced static camber requirements, thus minimizing uneven tire wear and increasing traction.
  • Improved steering feel and precision as steering input is directly translated into wheel movement.
  • Reduction/elimination of dynamic toe change, which along with handling benefits can also provide stability under braking.
  • Elimination of high breakaway torque requirement increases traction; allowing the tire to stay in closer contact with the track surface.

Kingpin Machine differentiates itself from the competition through our no compromise approach. All of our parts are designed, machined and tested right here in the United States. It is true that manufacturing quality products from properly graded, US sourced metal and utilizing the best available US produced bearings is more expensive. But it is not only the right thing to do, it ensures that you are running the safest and best performing parts available on the market.

While competitors may use inexpensive metal on metal bearings, low quality imports from unknown manufacturers or standard commercial (COM) series bearings; we prefer the vastly superior wear characteristics and higher radial/axial load ratings of the Aurora Performance Racing Series or the New Hampshire Ball Bearing Racing Series lines of bearings. Our overriding philosophy in selecting a bearing for an application is to offer the largest and highest quality bearing available. Our no compromise approach extends to material choice as well. We machine our bearing sleeves from 4140 HT (Heat Treated) steel and the vast majority of our spacers from 7075 Aluminum. These materials are more expensive than the standard mild steel and 6061 AL but the superior surface finish, additional strength and hardness are well worth the added expense.

Installation Service
When you select Kingpin Machine as your spherical bearing provider you are purchasing a service as much as a product. There are a number of reasons why our experience in assembly can actually save you time and money and more importantly ensure the safety and proper performance of your spherical bearing product.

  1. Stock control arms and suspension housings simply are not produced with the same level of precision as our products. There is no reason for auto makers to hold to exacting tolerances when using stock compliant rubber bushings. We produce our bearing sleeves in a range of outside diameters and the proper sleeve is chosen to produce just the right amount of interference when pressed into the control arm. Don’t take chances with “one size fits all” off the shelf solutions. The OD of the sleeves is often quite large to ensure they interference fit in the wide tolerance range of a factory arm. This tends to put undue stress on the control arm and bearing due to the excessive interference; possibly resulting in cracked arms, excessive wearing of the PTFE bearing liner and very high breakaway torque requirements for the bearing ball. Worse yet, a sleeve that does not have enough interference could fail on track. The off the shelf solutions also generally use aluminum bearing sleeves to more easily allow the oversize sleeve to be interference fit to the arm. However, aluminum sleeves can’t be tack welded to the arm and thus have no redundancy protection against failure. The aluminum is also easily galled by the extremely hard steel bearing and of course aluminum is not as strong or as hard as the 4140 steel sleeves we use.
  2. Pressing bushings out of control arms is generally a dangerous process that requires specialized equipment. We have already created fixtures and dies to hold suspension components in place while applying the immense pressure needed to press out stock bushings. We have the proper assembly tools such as a hydraulic-electric press, an arbor press, welding tools, retaining tools and products etc. and just as importantly the experience to do the job right.
  3. Finally, we are hopeless perfectionists. We bead blast and clean all arms after pressing out OEM bushings. Lower control arms are usually shot peened before bead blasting. Our bearing sleeves are then blueprinted to the suspension arms and TIG tack welded in place. Next the arms are sent out to be zinc electroplated for corrosion resistance and a beautiful finish. Finally the bearings are blueprinted to the bearing sleeves to ensure the perfect amount of stiction. Loctite 609 and a c-clip provide additional redundancy in most of our applications.