Lycoming IO-390-D Series Maintenance Manual page 198

(2) Complete a check of the end play clearance of the camshaft using a feeler gage (Figure
74).
(3) Remove the camshaft from the left crankcase half and install it in the right crankcase half
and complete a check of the camshaft end play clearance.
Acceptable end play
clearance.
NOTICE: If the end play clearance values are not within the
allowable limits, examine the crankcase and/or
camshaft for wear or damage. Replace a damaged
or worn camshaft. If one crankcase half is worn or
damaged, replace both crankcase halves as a
matched set.
(4) Apply engine oil mixture (15% pre-lubricant (STP or equivalent) and 85% SAE No. 50
mineral base aviation grade lubricating oil) to the camshaft slots and main bearings on
each crankcase half (Figures 75 and 76) and the camshaft lobes (Figure 78).
(5) Refer to the latest revision of Service Instruction SI-1059 and apply the specified
lubricant to the crankshaft thrust bearing surfaces of each crankcase half (Figure 77).
Figure 75
Main Bearings and Camshaft
Bearing Saddle in Crankcase Half
Figure 77
Thrust Bearing Surfaces of Each Crankcase Half
72-20
Page 172
0.002 to 0.015 in.
(0.051 to 0.381 mm)
IO-390-D Series Engine Maintenance Manual
IO-390-D Series Engine Maintenance Manual
Camshaft End Play
Clearance Check
Figure 76
Lubricant Application to Camshaft
Bearing Saddle in Crankcase Half
Figure 78
Lubrication on Camshaft Lobes
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Figure 74
March 2020