Up until 1998 the Land Cruiser used a straight front axle (or live axle) with closed steering knuckles. Each knuckle pivots side to side on knuckle bearings, also known as trunnion or king pin bearings. One top and one bottom of each steering knuckle. Knuckle bearings carry a large percent of the vehicle load - the bearings take a lot of abuse. Bearing wear occurs in the straight line position (see photo). Grooves wear into the bearing race and steering is no longer precise. To check for wear, put the front of the vehicle on jack stands and slowly turn the steering wheel side to side. If the wheels want to return to center or feel like they're clicking into detents, it is likely your bearings are worn. Another sign of wear would be loose knuckle arms.
Specter Off-Road sells a complete kit to correct this problem. The kit contains seals, knuckle bearings, gaskets and shims depending on model. The kit contains parts to do both steering knuckles. See part listing #080-400. If your bearings are in good shape but you are just servicing your knuckle and wheels bearings, SOR sells seal kits. The kits contain seals, shims and gaskets in one package to ensure you get what you need to complete the job. See part numbers #080-40 and #080-41. We also recommend consulting your service manual for procedures, torque settings and bearing load settings. To purchase a service manual, see pages 220, 221 and 223 The knuckle bearing kits do not contain wheel bearings.
While you're in there: If you are overhauling your steering knuckles, you will be disassembling the entire hub and knuckle and breaking free the tie rod ends. You may want to consider replacing your wheel bearings and brake pads. See part number 080-34 and 080-01 for inner and outer wheel bearings and page 081 for pads and shoes. You will run the risk of damaging tie rod boots so you may want purchase replacement boots see page 094.