SENSOR AS 4627838 - Caterpillar

The machine must be on a level, hard surface before a separation of the track is made. Any time a separation of both tracks is made, the machine must have blocks correctly positioned so the machine will not move.
To prevent personal injuty, never visually inspect the vent holes or valves to see if grease or oil is coming out of them. Make sure the vent holes are clean before the tension is released on the track. Watch the front roller frame to see that it moves.
Note: Use 30W power train oil or use multipurpose grease for the following procedure. If grease is used, make absolutly sure that no air is entrapped within the grease.
Pump the recoil cylinder until the cylinders are fully extended, and the track is tight.
Then, fully compress each recoil cylinder.
Use the following method to compress the cylinders. Place a 40 mm (1.5 inch) or larger steel pin in a sprocket tooth on the front side of the sprocket, just below the track engaging the sprocket. Move the tractor in reverse until the cylinder is fully compressed. While the cylinder is fully compressed, tighten the relief valve. Then, use 30W power train oil to pump the recoil until they are fully extended and the track is tight.
Extend and compress each cylinder four times to ensure no air is present in the system.
Close the relief valve.
Pump out the recoil cylinder until the average track sag is at the dimension shown below.
55 10 mm (2.2 0.4 inch)Note: The average sag dimension is determined by averageing the measured track sag between the front idler and carrier roller and between the carrier roller and sprocket.Additional Factors Causing Track Jumping
After assuring proper track adjustment and removal of any (potential) trapped air in the track adjuster cylinder, excessive idler recoil and track jumping may still occur. This is generally occurs when one or more of the following conditions are present.
Frequent tight turning in stiff underfoot conditions
Moving (in reverse) up a slope under load
A high amount of mud or debris packing in the track
A heavily equipped machine with one or more attachements such as a winch, ripper, slope board, spill plate, sweeps, etc.
Fatigue that has caused the recoil spring to weaken, loose preload, and loose spring rateTractors with Conventional Undercarriage
Tractors with a Heavy Duty or a Sealed and Lubricated Track may experience excessive idler recoil and track jumping. First ensure that the track adjuster cylinder has no trapped air and that the track tension is properly set, as previously discussed. Then determine if any of the five conditions that are listed above, are present. Excessive track jumping is often amplified when one or more of these factors are present at the same time. If the track is jumping from one or more of the above five machine conditions, the tractor should be upgraded to the new, stronger 251-8609 Spring .Tractors with SystemOne Undercarriage
An additional factor in excessive idler recoil and track jumping is the type of bushing that is used in