1.2.1 Valve Operating Mechanism
DETROIT DIESEL 53
Fig. 7. - Removing or Installing Cam Follower Roller and Pin with Tool J 5840
cam followers and related parts are removed for
Inspection
inspection.
Proper cam follower inspection and service are
necessary in obtaining continued efficient engine
performance. When any appreciable change in injector
timing or exhaust valve clearance occurs during engine
operation, the cam followers, and their related parts,
should be removed and inspected for excessive wear.
This change in injector timing or exhaust valve
clearance during engine operation can usually be
detected by excessive noise at idle speed.
After the cam followers are removed, wash them with
Use spring tester J 9666 and an accurate torque wrench
lubricating oil or Cindol 1705 and wipe dry. Do not use
to check the push rod spring load (Fig. 4). Replace the
fuel oil. Fuel oil working its way in between the roller
spring when a load of less than 250 pounds will
and bushing may cause scoring on the initial engine
compress it to a length of 2-9/ 64 ".
start-up since fuel oil does not provide adequate
lubrication. Wash only the cam follower associated
parts with fuel oil and dry them with compressed air.
Inspect the rounded end of the push rods for wear.
Replace any push rod which is worn or bent.
The purpose of a push rod spring is to maintain a
Examine the cam follower bores in the cylinder head
predetermined load on the cam follower to insure
contact of the cam roller on the camshaft lobe at all
times. Check the push rod spring load whenever the
1972 General Motors Corp.
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