Toro 500 EFI Service Manual page 110


NOTE: Do not use a new lock nut at this time as this
procedure may have to be repeated.
5. Place the assembled shaft into the left crankshaft
case; then lightly coat the gear teeth with machinist's
lay-out dye. Rotate the shafts through several rota-
tions in both directions. Gear contact should extend
from the root to the top of the gear teeth.
6. To adjust tooth contact, use the following chart to
correctly shim the driven shaft.
Tooth Contact
Contact at Top
Contact at Root
7. After correct tooth contact is established, proceed to
Checking Backlash in this sub-section.
Checking Backlash
1. If removed, install the secondary drive/bevel gear
shaft into the crankcase; then tighten the nut to 59 ft-
lb.
2. Install the secondary drive bearing support; then
install the secondary driven output shaft into the
crankcase.
3. Mount the dial indicator so the tip is contacting a
tooth on the secondary drive bevel gear.
4. While rocking the drive bevel gear back and forth,
note the maximum backlash reading on the gauge.
108
MT008B
MT016A
Shim Correction
Increase Shim Thickness
Decrease Shim Thickness
5. Acceptable backlash range is 0.127-0.381 mm
(0.005-0.015 in.).
Correcting Backlash

NOTE: If backlash measurement is within the
acceptable range, no correction is necessary.
1. If backlash measurement is less than specified,
remove an existing shim, measure it, and install a
new thinner shim.
2. If backlash measurement is more than specified,
remove an existing shim, measure it, and install a
thicker shim.

NOTE: Continue to remove, measure, and install
until backlash measurement is within tolerance. Note
the following chart.
Backlash Measurement
Under 0.127 mm (0.005 in.)
At 0.127-0.381 mm (0.005-0.015 in.)
Over 0.381 mm (0.015 in.)
After backlash and tooth contact are within specifica-
tions, apply red Loctite #271 to the driveshaft threads and
driven output shaft threads; then using new nuts, tighten
the output shaft nut to 59 ft-lb and the output yoke nut to
74 ft-lb.
CRANKSHAFT ASSEMBLY

NOTE: The crankshaft and connecting rod is a non-
serviceable assembly. If any component is out of
specification, the assembly must be replaced.
Measuring Connecting Rod
(Small End Inside Diameter)
1. Insert a snap gauge into the upper connecting rod
small end bore; then remove the gauge and measure
it with micrometer.
MT005A
Shim Correction
Decrease Shim Thickness
No Correction Required
Increase Shim Thickness