Running Gear Troubles

The running gear may suffer from oil leaks. To correct the trouble, clean the leaky spot and check visually for the cause of trouble. Loose fasteners should be tightened up and worn or damaged sealing arrangement components or damaged sealing gaskets replaced.

The most common troubles of the running gear of wheeled tractors and automobiles include excessive instability (wobble) of the damaged steerable wheels, punctured tires, damaged wheels, and bent front axle. All these troubles are conducive to traffic accidents and therefore it is prohibited to operate vehicles showing any of the above conditions.

The instability of the front wheels may be caused by worn steering knuckle pivots and their bushings and thrust bearings or by worn or loose wheel bearings. Worn components should be replaced and loose bearings adjusted properly. Tо adjust wheel bearings, the wheel should be jacked up.

Inner tube leaks due to punctures and other minor injuries can be patched en route either by the cold-patch method (i.e., by cementing a rubber patch to the tube) or by the hot-patch method (i.e., by vulcanizing a patch of uncured rubber to the tube). Damaged tire casings should be repaired, if repairable, at a garage or specialized shop. Badly damaged tires should be discarded.

Wheel discs or rims may be damaged as a result of careless driving. Loose wheel mounting bolts or nuts may cause damage to the bolts holes in the wheel discs, which may render the discs irrepairable. Damaged wheels and bent front axles should be repaired.

In the course of service, suspension springs gradually weaken and their eye bolts and bush­ings wear down. Careless driving may result in a broken leaf in a leaf spring. Weak springs will sag, causing the tires to rub against the body of the vehicle and thus wear rapidly. Driving a vehicle with a broken spring will cause the axle to skew and will make it difficult for the driver to keep the vehicle moving straight ahead. Weak and broken suspension springs should be replaced.

Special attention should be given to the track tension in crawler tractors. Both excessive and insufficient track tension accelerate wear of the tracks and cause the tractor engine to lose power in propelling the tractor. Moreover, a loose track with badly worn links may come off the tractor.

ADJUSTING THE TRACK TENSION. To check a track for tension, place the tractor on an even and hard surface. Do it in such a way as to make tight the track section between the rear track support roller and the drive sprocket. Place a straight batten on the projecting ends of the track link pins above the track support rollers and measure the distance from the batten to the track link that sags most. This distance must be from 30 to 50 mm. Repeat the procedure for the second track. Both tracks must have an equal amount of sag.

If the track tension proves to be improper, it should be adjusted. To adjust a track for proper tension, clean the track adjusting mechanism from dirt and lubricate the threaded portion of the track idler adjusting rod with grease. Loosen the lock nut and turn the adjusting nut clockwise (when facing the rear of the tractor) to tighten the track. To loosen the track, turn the adjusting nut counterclockwise. After making adjustment, tighten the lock nut. Should the length of the threaded portion of the track idler adjusting rod prove insufficient for tightening the track properly, remove one track link from each track and make adjustment once more. Adjust each track an equal amount.