DETROIT DIESEL 53
Piston and Piston Rings 1.6
Fig. 8 - Measuring Piston-to-liner Clearance
With the piston, fixture and reamer in alignment, tighten the wing nuts securely.
Fig. 9 - Measuring Piston Ring Gap
d. Ream the bushings (Fig. 7). Turn the reamer in a clockwise direction only, when reaming or with- drawing the
reamer. For best results, use only moderate pressure on the reamer.
e. Withdraw the reamer and remove the piston from the fixture. Blow out the chips and measure the inside
diameter of the bushings. The diameter must be 1.3775" to 1.3780".
Measure the piston skirt diameter lengthwise and crosswise of the piston pin bore. Measurements should be taken at
room temperature (70° F.). The taper and out-of-round must not exceed .0005". Refer to Section 1.0 for piston
A new cylinder liner has an inside diameter of 3.8752 " to 3.8767 ". The piston-to-liner clearance, with new parts, is .0031
" to .0068" (non-turbocharged engines). A maximum clearance of .010" (non-turbocharged engines) is allowable with
With the cylinder liner installed in the cylinder block, hold the piston upside down in the liner and check the clearance in
four places 90° apart (Fig. 8). Use feeler gage set J 5438 to check the clearance. The spring scale, attached to the
proper feeler gage, is used to measure the force in pounds required to withdraw the feeler gage.
Fig. 10 - Measuring Piston Ring Side Clearance
April, 1974 SEC. 1.6 Page 5