GM Full Size Vans 1967-1986 Repair Guide

I-Beam Axle



When these pivot parts wear out, the result is rapid wear on the inside of the front tires, shimmy, a clunking sound on bumps, and excessive steering play.

  1. Raise and support the front axle. Remove the wheel and the brake drum.
  3. Unbolt and remove the brake backing plate. Wire it up to prevent hose damage.
  5. Detach the steering arm and tie rod, using a tie rod stud removal tool.
  7. Remove the upper and lower kingpin dust caps. Remove the kingpin lockpin nut and lockpin from the axle.
  9. Tap the kingpin out from the bottom. Remove the steering knuckle from the axle, along with the shims and thrust washer.
  11. Clean all parts. If there is excessive wear in the axle end, it can be machined to take an oversize kingpin. Clean up the bushing bores with emery cloth and wipe them clean. Lubricate the outside of the bushings and push them into the steering knuckle. Lubricate and place a new O-ring in the upper knuckle bore under the upper bushing on G-10 and 1500.
  13. Place the steering knuckle and the original shims on the axle end. Be careful of the upper seal on the G-20 and 2500 axle.
  15. Slide the new thrust washer assembly between the lower side of the axle and the steering knuckle. The thrust washer assembly is a bronze washer between tow steel washers, all encased in a dust shield. The G-20 and 2500 has an extra outer seal which must go over the thrust washer assembly.
  17. Lubricate the kingpin and install it temporarily.
  19. Raise the knuckle with a jack to take up all the clearance. Use feeler gauges to measure the clearance between the top of the axle and the steering knuckle. On G-10 and 1500, the clearance must be less than 0.005 in. (0.127mm). On G-20 and 2500, it should be 0.003-0.008 in (0.0762-0.203mm). Add shims at the top to correct the clearance.
  21. On final assembly, make sure the lockpin slot aligns with the hole. Install the lockpin and tighten the nut.
  23. Install the kingpin dust caps with new gaskets.
  25. Replace the brake backing plate, brake drum, and wheel. Replace the steering and tie rods.
  27. Adjust the front wheel bearings and check the toe-in.