Jeep Cherokee 1999 Electronic Service Manual page 1149

9 - 36 ENGINE
REM OVAL AN D I N STALLAT I ON (Cont inue d)
Fig. 56 Ring Gap Measurement
.102m m (.0027 t o .0040 in .). Oil con t r ol r in g ga p .040
t o .072m m (.0015 t o .0028 in .).
Fig. 57 Piston Ring to Groove Clearance
PISTON RINGS—INSTALLA TION
(1) In st a ll r in gs on t h e pist on s u sin g a su it a ble
r in g expa n der (F ig. 58).
(2) Top com pr ession r in g is t a per ed a n d ch r om iu m
pla t ed. Th e secon d r in g is of t h e scr a per t ype a n d
m u st be in st a lled wit h scr a pin g edge fa cin g bot t om of
t h e pist on . Th e t h ir d is a n oil con t r ol r in g. Rin g ga ps
m u st be posit ion ed, befor e in ser t in g pist on in t o t h e
lin er s, a s follows (F ig. 60).
(3) Top r in g ga p m u st be posit ion ed a t 30 degr ees
t o t h e r igh t of t h e com bu st ion ch a m ber r ecess (look-
in g a t t h e pist on cr own fr om a bove).
Fig. 58 Piston Rings—Removing and Installing
Fig. 59 Piston Ring Identification
(4) Secon d pist on r in g ga p sh ou ld be posit ion ed on
t h e opposit e side of t h e com bu st ion ch a m ber r ecess.
(5) Oil con t r ol r in g ga p t o be loca t ed 30 degr ees t o
t h e left of com bu st ion ch a m ber r ecess.
(6) Wh en a ssem blin g pist on s ch eck t h a t com po-
n en t s a r e in st a lled in t h e sa m e posit ion a s befor e dis-
a ssem bly, det er m in ed by t h e n u m ber s st a m ped on
t h e cr own of in dividu a l pist on s. E n gin e cylin der s a r e
n u m ber ed st a r t in g fr om gea r t r a in en d of t h e en gin e.
F a c e c h a m be r re c e s s s id e o f p is to n to w a rd s
c a m s h a ft. Th er efor e, t h e n u m ber s st a m ped on con
r od big en d sh ou ld a lso fa ce in t h e sa m e dir ect ion . To
in ser t pist on in t o cylin der u se a r in g com pr essor a s
sh own in (F ig. 58).
PISTON PIN INSTALLA TION
(1) Secu r e con n ect in g r od in soft ja wed vice.
(2) Lu br ica t e pist on pin a n d pist on wit h clea n oil.
(3) P osit ion pist on on con n ect in g r od.
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