DETROIT DIESEL 53
1.7.3
GEARS
CAMSHAFT
The two camshaft gears on a V-type engine, are located
at the flywheel end of the engine and mesh with each
other and run at the same speed as the crankshaft.
Since the two camshaft gears on V-type engine must be
In time with each other, timing marks are stamped on
the rim of each gear. Also, since these two gears as a
unit must be in time with the crankshaft, timing marks
are located on the idler and crankshaft gears (refer to
Section 1.7.1).
Each gear is keyed to its respective shaft and held
securely against the shoulder on the shaft by a nut. A
gear nut retainer, with a double hexagon hole in the
center, fits over the nut. The retainer is attached to the
gear by bolts threaded into tapped holes in the gear.
Remove Camshaft Gears
Fig. 1. - Removing Camshaft Gear
1. Remove the camshaft from the engine as outlined in
Section 1.7.2.
Inspection
2. Place the camshaft and gear assembly in an arbor
Clean the gears with fuel oil and dry them with
press with the gear suitably supported as shown in Fig.
compressed air. Then examine the gear teeth for
1.
evidence of scoring, pitting and wear. Replace the
gears if necessary.
3. Place a wood block under the lower end of the
camshaft so the threads will not be damaged when the
Examine both faces of the camshaft thrust washer and,
shaft IS pressed from the gear.
if either face is worn or scored, replace the washer.
Also examine the surface on the camshaft which the
4. Place a short piece of 3/4" O.D. brass rod between
thrust washer contacts. If this surface is scratched, but
the end of the camshaft and the ram of the press; then
not severely scored, smooth it up with a fine oil stone.
force the camshaft out of the camshaft gear.
Install Camshaft and Balance Shaft Gears
5. Remove the thrust washer, Woodruff key and
spacer from the camshaft.
1. Note the letters stamped on the end of the camshaft
which signify the engine models in which a camshaft
may be used. The letters on the timing gear end of the
camshaft must correspond with the engine model of the
particular engine being assembled. Refer to the front of
this manual for engine model identification.
2. Place the rear camshaft spacer over the timing gear
end of the camshaft and install the Woodruff key.
3. Lubricate the thrust washer with clean engine oil and
place the thrust washer over the gear end of the
camshaft and the spacer.
1972 General Motors Corp.
July, 1970
SEC. 1.7.3 Page 1
