Gravely 950001, Maintenance Manual

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4.22 CHECK TRACTION DRIVE CHAIN
TENSION
IMPORTANT: If conditions are sandy, an additional 1/2
inch of slack should improve chain performance.
Each front hub is direct-coupled to a hydraulic motor.
The rear hubs are mounted on a fixed axle with the
hubs running on tapered rolled bearings. The front hub
drives are connected to the rear hubs by a roller chain.
A sliding chain tensioner takes up slack in the chain.
The chain tensioner is self compensating for direction
of travel. The drive chains are enclosed with a steel
chain guard. Each of the two roller chains are fitted with
two “half links” that can be removed to shorten the
chain as wear and slack increase.
To check chain tension:
1. Place the unit on jackstands. Remove the wheels
from the unit.
2. Remove the three hex head bolts and two nuts that
secure each chain guard. Remove the guards.
3. On each side, check chain for proper slack by lifting
the chain tensioner up by hand. If the top plastic
slider of the chain tensioner comes within 1/2”
(13 mm) of the main frame above it, the chain is too
slack.
4. If slack is correct in both chains, proceed to step
11. If chain(s) are too slack, follow steps 5-10 for
the chain(s) that must be adjusted.
To adjust chain tension:
5. If chain is too slack, first try reversing tensioner
blocks. If this is insufficient, removal of chain half
links is required.
6. Remove the split pins from the “half links” then
remove one or both half links as needed.
NOTE: The split pins on the right hand side are
arranged to oppose the pins on the left hand side. This
is important to prevent the pins from being “snagged”
during chain movements.
NOTE: While the chain is off the sprocket check for
damage such as broken rollers. Replace if wear or
damage is excessive.
7. Wash the chain in a petroleum based solvent.
Allow to dry, then soak in oil.
8. Install the chain around the sprockets and
between the tensioners.
FINAL DRIVE TRAIN Rear Hub
Chain Tensioner
Front Hub
Note how the split pins on the right hand
side are arranged to oppose the pins on the
left hand side, this is important in preventing
the pins from being “snagged” during chain
movements causing possible pin removal.
Split Pins
Normal Sprocket
Worn Sprocket
Normal Sprocket Worn Sprocket