Troy-Bilt 7 HP Technical Manual page 35

PTO HORSE MODEL
TECHNICAL MANUAL
Page 6-5 4/90
SECTION 6: Tiller Attachment Transmission
e·
b. Force the shaft down. This will
dislodge one bearing (7). Also
remove the washer (9), if so
equipped.
10. Turn the shaft assembly 180
degrees and use the arbor press to
dislodge the other bearing (and
washer, if so equipped).
11. Slide the worm gear (10) off
the shaft.
12. Remove the Woodruff key
(11), if necessary.
Inspection
These instructions describe how
to inspect parts on the tiller tine
shaft. In addition to inspecting the
parts you have removed, you
should also inspect any replace-
ment parts you will use.
Note:
Thoroughly degrease and
clean all parts before inspection.
Tiller Tine Shaft - The shaft
should not be scored, pitted, or
corroded in the areas where the
oil seals are located. If the shaft is
scored, pitted, or corroded, try
using an emery cloth to clean the
area. If the scoring, pitting, or cor-
rosion is too extensive, discard the
shaft.
Also, remove any burrs or rough
spots on the ends of the shaft.
Bronze Worm Gear - If the gear
teeth are damaged or excessively
worn, discard the gear.
Bearings - If the bearing has a
bluish color then proper lubrica-
tion has not been maintained; dis-
card the bearing and bearing cup.
Also, if the bearing or its cup is
scored or excessively worn, dirt
may have gotten inside the hoU$-
ing. If so discard the bearing and
bearing cup.
Test each roller in the bearing by
spinning it with your fingers. If a
roller makes a growling noise or
does not move at all, discard the
bearing.
Washers (on tillers so equipped)
You will only be able to inspect the
washers if you should need to dis-
assemble the shaft. If a washer is
warped, discard it.
Installation
1. Install the Woodruff key (11) in
the shaft.
2. Slide the bronze worm gear
(10) on the shaft. The worm gear
should be centered over the key.
3. Use an arbor press to replace
a bearing (and washer, if so
equipped). Make sure the washer
is between the bearing and the
bronze worm gear.
Note: If an arbor press is not
available, use the housing cover
(without the oil seal installed) as a
centering device. Simply support
the cover on open vise jaws and
place the bearing in the bearing
cup (cup must be installed in
cover). Add the washer (if so
equipped) and tap the shaft down
with a soft mallet. Repeat this
procedure for the other end, mak-
ing sure the bronze worm gear is
centered over the key.
4. Turn the shaft 180 degrees and
use an arbor press to replace the
other bearing (and washer, if so
equipped). Check to make sure
the bronze worm gear is centered
over the key.
5. Use an emery cloth to clean
the tine shaft, especially around
the oil seal locations.
6. Replace the bearing cup (8) in
the housing cover (3) by using a
piece of wood as a driver to seat
the cup. Make sure the tapered
bearing cup is oriented correctly
to receive the bearing. Also make
sure the bearing cup goes fully
inside the cover; no metal should
and the inside edge of the cover.
7. Use the same technique to
replace the bearing cup (8) in the
right side of the tiller housing.
8. If not already installed, install
the tiller drive shaft assembly. See
the installation instructions in this
section.
9. Insert the tiller tine shaft
assembly (5) in the tiller housing.
Make sure the side on the bronze
worm gear whose gear edges are
the sharpest is facing towards the
rear of the machine.
Note: Since the front of each gear
tooth gets little wear and the rear
of each tooth gets most of the
wear, rotate the gear so that the
best side is facing the rear.
10. Install a new gasket (4) on
the tiller housing cover (3). As you
begin the shimming procedure,
start with the thinnest gasket,
which is .010". Do not install the
oil seals (6) at this time.
11. Bolt the cover on using two
bolts (1) about 180 degrees apart.
Note: Even without the bolts
installed, you should not be able
to wiggle the cover from side to
side or rotate it. Do not use the
cover if you can.
12. Check the tine shaft for play:
a. Using two hands, grasp the
tiller tine shaft and rotate the shaft
back and forth.
b. You should be able to rotate
the shaft slightly and to hear a
small click. This means the tiller
tine shaft is shimmed correctly.
c. If you cannot rotate the shaft
and do not hear a click, remove
the .010" gasket and install a .030"
gasket. If necessary, begin using
gaskets in pairs to gradually
increment the thickness of the
gasket. For example, if a .030"
gasket is insufficient; use a .030"
and .010" gasket together. If these