Trencher Maintenance; Replacing The Digging Teeth; Checking And Adjusting The Digging Chain And Boom; Replacing The Drive Sprocket - Toro TRX-20 Operator's Manual

Trencher Maintenance

Replacing the Digging Teeth

Service Interval: Before each use or daily—Check the
condition of the digging teeth and
replace any that are worn or damaged.
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 37 to 45 N-m (27 to 33
ft-lb).
Checking and Adjusting the
Digging Chain and Boom
Service Interval: Every 25 hours
•
Check each link in the chain for excessive wear, such as
links that will no longer hold teeth.
•
Inspect the bottom of the boom for wear
•
With the trencher parallel to the ground, ensure that there
are 3.8 to 6.3 cm (1-1/2 to 2-1/2 inches) between the
bottom of the boom and the top of the bottom chain
span. If not adjust the chain tension.
Important: Do not over tighten the chain. Excess
chain tension may damage drive components.
To replace a worn chain, flip or replace a worn boom, or to
adjust the chain tension, use the following procedure:
1. To replace the chain or to flip or replace the boom,
complete the following:
A. Remove the 2 bolts and nuts securing the boom
to the trencher arm
Figure 59
1. Bolts
2. Jam nut
3. Adjusting bolt
B. Loosen the jam nut on the adjusting bolt in the
boom.
C. Loosen the adjusting bolt until you can remove
the chain from the boom
D. Remove the chain from the drive sprocket.
E. If the chain needs replacing, remove the bolt and
nut securing the spoils auger and remove the
auger and chain.
F. Remove the boom, flip it over so the bottom
becomes the top (or if you have already flipped it
once, replace it), and install the boom again.
G. Replace the nuts, bolts, and washers securing the
boom.
H. If installing a new chain, connect the links by
pressing or hammering the clevis pin supplied
with the chain through the links, then secure the
clevis pin with the cotter pin supplied with the
chain.
Important: To avoid bending the chain links,
place blocks under and between the links
when hammering the clevis pin through.
I. Install the chain over the drive sprocket and front
roller.
J. If you removed the spoils auger, install it using the
bolt and nut you removed previously. Torque the
bolt and nut to 102 N-m (75 ft-lb).
K. Skip to step 4 to complete the adjustment.
2. Loosen the 2 bolts and nuts securing the boom to the
trencher arm
3. Loosen the jam nut securing the adjustment bolt.
4. Turn the adjustment bolt in or out as needed to achieve
the desired tension.
5. Tighten the jam nut.
6. Torque the 2 bolts and nuts securing the boom to 183
to 223 N-m (135 to 165 ft-lb).

Replacing the Drive Sprocket

Over time, 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 (Figure 60).
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