1.7.5
DETROIT DIESEL 53
CRANKSHAFT TIMING GEAR
Engine
In-line
The crankshaft timing gear is keyed and pressed on
Inspection
the crankshaft and drives the camshaft gear (In-line
engines) or balance shaft gear (In-line engines)
Clean the gear with fuel oil and dry it with
compressed air Examine the gear teeth for evidence
through an idler gear.
of scoring. pitting or wear. If severely damaged or
worn. install a new gear. Also check the other gears in
Since the camshaft must be in time with the
the gear train.
crankshaft. timing marks are located on the rim of the
idler gear with corresponding timing marks stamped
on the crankshaft gear and camshaft and balance
shaft gears (refer to Section 1.7.1).
Install Crankshaft liming Gear
1. If removed, install the Woodruff key in the keyway
in the crankshaft.
Remove Crankshaft liming Gear (Flywheel
Housing Removed)
2. Start the timing gear over the end of the crankshaft
with the timing marks on the outer rim of the gear
The crankshaft timing gear is a 001" to .003" press
facing out and the keyway in the gear in alignment
fit on the crankshaft. Remove the gear as follows:
with the Woodruff key in the crankshaft.
3. Align the proper timing mark on the crankshaft
1. Remove the crankshaft rear oil seal sleeve, if used.
gear with the corresponding mark on the idler gear
To remove the sleeve, peen the outside diameter of the
(refer to Section 1.7.1 ).
sleeve until it stretches sufficiently so it can be slipped
off of the crankshaft.
NOTE: When advanced timing is required, align
the timing mark "A" with the timing mark on
2. Before removing the crankshaft gear, align the
the idler gear.
timing marks of the gear train and note their location
so the gear can be reinstalled in its original position.
4. Place a heavy hammer against the head of the bolt
in the front end of the crankshaft. Place installer
3. Attach bar type puller J 4871 to the crankshaft gear
J 7557 against the rear face of the timing gear and
with three long bolts or hooks, flat washers and nuts
through the holes in the gear as shown in Fig. 1.
4. Turn the center screw of the puller to pull the
crankshaft gear off of the crankshaft.
Fig. 1. Removing Crankshaft Timing Gear
Fig. 2. Installing Crankshaft Timing Gear
March, 1973
SEC. 1.7.5 Page 1
