1.2 Cylinder Head
DETROIT DIESEL 53
Fig. 7 - Removing or Installing Cam Follower Roller and Pin with Tool J 5840
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 lubricating oil or Cindol 1705 and wipe dry. Do not use fuel oil. Fuel
oil working its way in between the roller and bushing may cause scoring on the initial engine 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 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 cam followers and related parts are
removed for inspection.
The current push rod spring is made from .192" diameter wire and was first used only in the injector cam follower
position, effective with engine 3D-3792.
Effective with engine 3D-6128 the new spring is also used in the exhaust valve cam follower position. The former push
rod spring was made from .177 " diameter wire.
Use spring tester J 9666 and an accurate torque wrench to check the push rod spring load (Fig. 4). Replace the current
type spring when a load of less than 250 pounds will compress it to a length of 2-9/64 ". Replace the former type spring
when a load of less than 172 pounds will compress it to a length of 2-1/8 ".
It is recommended that if one former type push rod spring requires replacement, all of the former type springs in either
the injector or valve cam follower positions be replaced by the current type spring. A new design upper spring seat is
required with the use of the current push rod spring.
Examine the cam follower bores in the cylinder head
Page 4
