Replacing the Digging Teeth
Service Interval:
Before each use or daily
Due to the high amount of wear placed on the digging
teeth, you will need to replace them periodically.
To replace a single tooth, remove the bolts securing the
tooth to remove it, then install a new tooth in the same
position. Torque the bolts securing the teeth to 27 to 33
ft-lb (37 to 45 N-m).
Replacing the Drive Sprocket
Overtime, the drive sprocket will wear, especially when
used in sandy or clay soils. When this happens, the
digging chain will begin to slip. If the chain slips, replace
the drive sprocket, as follows:
1. Raise the trencher a few inches above the ground.
2. Stop the engine and remove the key.
3. Remove the spoils auger (Fig. 8).
G008941
1
2
3
Figure 11
1.
Spoils auger
3.
Bolts
2.
Drive sprocket
4. Loosen the 2 bolts and nuts securing the boom to
the trencher arm (Fig. 2).
5. Loosen the jam nut on the adjusting bolt in the
boom (Fig. 2).
6. Loosen the adjusting bolt until you can remove the
chain from the boom (Fig. 2).
7. Remove the chain from the drive sprocket.
8. Remove the 6 bolts securing the drive sprocket (Fig.
8).
9. Remove and discard the drive sprocket (Fig. 8).
10. Clean the sprocket mounting surface on the trencher.
11. Slide the new sprocket onto the shaft as illustrated
in Figure 8.
Important:
The arrow on the sprocket face
should be visible from the right side of the
trencher and should point in a clockwise
direction; if not, turn the sprocket around.
12. Thread the 6 bolts into the sprocket finger tight (Fig.
8).
13. Slowly begin tightening the bolts progressing around
the sprocket until all bolts are torqued to 95 to 115
ft-lb (129 to 155 N-m).
Important:
Tighten each bolt only half way
first, working your way around the six bolts,
then return to each bolt in turn and torque them
to the specifications given in step 13.
14. Loop the chain over the auger drive shaft and onto
the drive sprocket, ensuring that the teeth point
forward on the upper span.
15. Set the upper span of the chain into place on the
trencher boom, then wrap the chain around the
roller at the end of the boom.
16. Thread the adjustment bolt into the boom and turn
it in until there is 1-1/2 to 2-1/2 inches (3.8 to 6.3
cm) of slack in the chain on the bottom span.
17. Thread the jam nut down the adjusting bolt and
tighten it securely against the boom.
18. Torque the 2 bolts and nuts securing the boom to
135 to 165 ft-lb (183 to 223 N-m).
19. Install the spoils auger; refer to Installing the Spoils
Auger.
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