DRESSTA TD-25M EXTRA, Service Manual

Page: 552 / 595

SECTION 15
TRACKS OR WHEELS
Page 6
TD-25M EXTRA DRESSTA
TRACK CHAIN
DANGER! Everyone must be clear and well away from the track chains and dozer
before performing step 3 and 4. When the sprocket rotates, the track chain will roll
rearward, falling to the ground, which can cause serious bodily injury or death.
3. Start the machine and slowly turn the sprocket. Continue to rotate the sprocket slowly until upper
section of the track chain is on the ground and free of sprocket.
4. Place a plank flush against the rear of the track when the track is flat on the ground as shown
in Fig. 15.4. The plank should be approximately the same thickness as the track and long
enough so that the entire dozer can rest on the plank. If a new track is to be installed, remove
the old chain as described above, and place the new chain on the ground ahead of the dozer,
with the open link end flush against the front of the old chain.
Fig. 15.4. Removing Track Chain
1. End with Wearing Surface
2. New Track 3. End with No Wearing Surface
4. Plank or Old Track
7. TRACK CHAIN REPAIR
To repair or replace worn track pins, bushings or links, a hydraulic track press will be necessary.
The operation and procedure instructions for each track press will vary, so specific disassembly
instructions will be found with the manufacturer’s operational instructions.
Sprocket wear must also be considered in conjunction with track chain wear. Wear of sprocket
teeth decreases pitch length of track. Results are that pitch lengths of sprocket and track become
more and more out-of-phase; and bushings ride higher on sprocket teeth. Combined wear
of sprocket and track should never be allowed to reach this point as spinning of sprocket may
result and cause serious breakage. Whenever new or rebuilt track chains are installed sprockets
should also be replaced.
Never remove one link to bring a stretched track to within range of proper track adjustment.
A track that is worn badly enough to take up length of one link will be so far out of pitch that
increased wear on sprocket will far more than offset saving obtained by removal of one link in track
chain. Refer to CHECKING UNDERCARRIAGE WEAR in SECTION 14.
LUBRICATED TRACK SYSTEM
Sealed and lubricated track pins have a hollow center which is used as an oil reservoir.
A cross-drilled passage permits oil to enter bushings for lubrication of pins, bushings and oil seals.
If seals become dry, dirt can enter and cause sealing surface of bushing to wear. Track chains are
factory lubricated; no oil level checks are necessary.
Leaking joints can be detected by any of following methods: