PISTONS, PISTON PINS, AND RINGS REPLACEMENT - continued

TM 10-3930-673-34

3-16. PISTONS, PISTON PINS, AND RINGS REPLACEMENT (CONT)

(6)

Measure and record piston ring gaps

while rings are in cylinders. Gaps

should be as follows:

Piston Ring Gaps

Top ring gap

0.0160 - 0.0275 in.

(0.41 - 0.70 mm)

Intermediate

0.0100 - 0.0215 in.

ring gap

(0.25 - 0.55 mm)

Oil control

0.0100 - 0.0215 in.

ring gap

(0.25 - 0.55 mm)

TR01070

(7)

If gaps are excessive, select next

oversized ring set.

(8)

If gaps are too close, and new piston

sleeves have been installed, bore out

piston sleeves as necessary to allow

gaps to open up to specifications.

(9)

Install oil control ring expander (8)

and piston rings (5, 6, and 7) on

piston (2).

(a)

Place oil control ring expander (8) in

bottom groove of piston (2).

TR01071

(b)

Install oil control ring (7) over

expander (8), with gap at a point

120 from gap in expander.

(c)

Install intermediate ring (6), placing its gap at a point 120 from gap in oil control ring (7).

(d)

Install top ring (5), placing its gap at a point 120 from gap in intermediate ring (6).

NOTE

Follow-on Maintenance: Install pistons and connecting rods (Para 3-17).

END OF TASK

3-110