The track frame, as the name implies, serves as a framework and support for the track assembly, rollers, front idler, recoil spring, and adjusting mechanism.
Track frame alignment may be fixed or shim adjusted depending on the manufacturer. When shims are used, there are a couple of ways alignment may be maintained. One way is using shims where the frame attaches to the rear pivot and also near the center of the track frame where it is mounted against the main frame guide brackets. Another way is to use a diagonal brace and shims at the rear pivot to align the track frame.
Track Frame Rollers
Carrier rollers (fig. 6-24) are single-flanged rollers mounted on brackets, which extend above the track frame and supports the track assembly. Two of these rollers are on each side of the tractor. The flange extends upward between the links of the track chain. keeping the chain in alignment between the drive sprocket and the front idler.
Track rollers (fig. 6-25) are double-and single-flanged rollers that supports the weight of the tractor, ensures that the track chain is aligned with the track frame at it passes under the rollers, and prevents side to side track movement and derailment. In a normal arrangement, a double-flanged roller is directly in front of the drive sprocket, followed by a single-flanged roller. The rollers alternate forward to the front idler.
The front idler, as shown in figure 6-25, serves as a guiding support for the track chain. The idler is spring-loaded and mounted on slides or guides that allow it to move back and forth inside the track frame, as the tractor passes over uneven terrain. The spring loading effect causes the idler to maintain the desired tension regardless of operating conditions.
Figure 6-25.- Track rollers in position in the track frame..
Figure 6-24.- Track carrier rollers.
tractors have manual adjustments, whereas newer tractors are adjusted hydraulically with a grease gun. Grease is pumped into the yoke cylinder and extends it until enough tension is placed on the recoil spring to remove the slack from the track. Tension is released by loosening the vent screw located next to the adjustment fitting.
DO NOT lubricate the adjustment fitting when performing maintenance on the tractor.