Timing gears
(1)
Be sure that the backlash in each mesh is within
the repair limit. If the limit is exceeded, reduce
the backlash by replacing the worn gear. To
measure backlash, use a thickness gauge: put the
gauge squarely into between two gear teeth.
Specifications
Unit: mm (in.)
Item
Standard
Repair
limit
Backlash
0.05 - 0.20
0.25
(0.0020 - 0.0079) (0.0098)
(2)
Check the radial clearance between idler bu,hing
and shaft by miking. Compute the clearance from
the readings taken and, if the repair limit is
exceeded, replace the bushing.
Specifications
Unit: mm (in.)
Item
Nominal
Standard
Repair
limit
Fit of shaft
36
0.025 -0.075
0.1
in idler
bushing
(1.417)
(0.00098-0.00295) (0.004)
(3)
Check the idler end play with a thickness gauge.
Replace the thrust plate to reduce the play if the
thickness gauge reading exceeds the repair limit.
Specifications
Unit: mm (in.)
Item
Standard
Repair
limit
Idler end play
0.05 -0.15
0.35
(0.0020 -0.0059)
(0.0138)
(4) If the idler shaft has to be replaced, use the idler
shaft puller to remove it, as shown. When installing
the replacement shaft, check to be sure that the
oil holes are aligned.
(5) Inspect the timing gears as follows:
(a) Camshaft gear
Replace the gear if its teeth show evidence of
flaking or excessive wear, or if its keyway is
galled, worn or otherwise disfigured. Make sure
that the camshaft gear as mounted on the
camshaft has no more end play than
0.4
mm
(0.0157 in.): to check the end play, use a dial
gauge. If the reading exceeds the repair limit,
replace the thrust plate. (Remember, this gear
is shrink-fitted to the camshaft.)
Checking idler end play
