Jeep Cherokee 1999 Electronic Service Manual page 1040

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SERV I CE PROCEDU RES (Cont inue d)
(11) F OR EXAMP LE: If t h e in it ia l clea r a n ce wa s
0.0762 m m (0.003 in ch ), 0.025 m m (0.001 in ch )
u n der size in ser t s wou ld r edu ce t h e clea r a n ce by
0.025 m m (0.001 in ch ). Th e clea r a n ce wou ld be 0.002
in ch a n d wit h in specifica t ion . A 0.051 m m (0.002
in ch ) u n der size in ser t wou ld r edu ce t h e in it ia l clea r-
a n ce a n a ddit ion a l 0.013 m m (0.0005 in ch ). Th e
clea r a n ce wou ld t h en be 0.038 m m (0.0015 in ch ).
(12) Repea t t h e P la st iga ge m ea su r em en t t o ver ify
you r bea r in g select ion pr ior t o fin a l a ssem bly.
(13) On ce you h a ve select ed t h e pr oper in ser t ,
in st a ll t h e in ser t a n d ca p. Tigh t en t h e con n ect in g r od
bolt s t o 45 N·m (33 ft . lbs.) t or qu e.
SIDE CLEARANCE MEASUREMENT
Slide sn u g-fit t in g feeler ga u ge bet ween t h e con -
n ect in g r od a n d cr a n ksh a ft jou r n a l fla n ge (F ig. 18).
Refer t o E n gin e Specifica t ion s for t h e pr oper clea r-
a n ce. Repla ce t h e con n ect in g r od if t h e side clea r a n ce
is n ot wit h in specifica t ion .
Fig. 18 Checking Connecting Rod Side Clearace—
FITTING CRANKSHAFT MAIN BEARINGS
INSPECTION
Wipe t h e in ser t s clea n a n d in spect for a bn or m a l
wea r pa t t er n s a n d for m et a l or ot h er for eign m a t er ia l
im bedded in t h e lin in g. Nor m a l m a in bea r in g in ser t
wea r pa t t er n s a r e illu st r a t ed (F ig. 19).
NOTE: If any of the crankshaft journals are scored,
remove the engine for crankshaft repair.
In spect t h e ba ck of t h e in ser t s for fr a ct u r es, scr a p-
in gs or ir r egu la r wea r pa t t er n s.
In spect t h e u pper in ser t lockin g t a bs for da m a ge.
Repla ce a ll da m a ged or wor n bea r in g in ser t s.
Typical
Fig. 19 Main Bearing Wear Patterns
FITTING BEARINGS (CRANKSHAFT INSTALLED)
Th e m a in bea r in g ca ps, n u m ber ed (fr on t t o r ea r )
fr om 1 t h r ou gh 5 h a ve a n a r r ow t o in dica t e t h e for-
wa r d posit ion . Th e u pper m a in bea r in g in ser t s a r e
gr ooved t o pr ovide oil ch a n n els wh ile t h e lower
in ser t s a r e sm oot h .
E a ch bea r in g in ser t pa ir is select ively fit t ed t o it s
r espect ive jou r n a l t o obt a in t h e specified oper a t in g
clea r a n ce. In pr odu ct ion , t h e select fit is obt a in ed by
u sin g va r iou s-sized color-coded bea r in g in ser t pa ir s
a s list ed in t h e Ma in Bea r in g F it t in g Ch a r t . Th e
bea r in g color code a ppea r s on t h e edge of t h e in ser t .
Th e s ize is n o t s ta m p e d o n be a rin g in s e rts u s e d
fo r e n g in e p ro d u c tio n .
Th e m a in bea r in g jou r n a l size (dia m et er ) is iden t i-
fied by a color-coded pa in t m a r k on t h e a dja cen t
ch eek. Th e r ea r m a in jou r n a l, is iden t ified by a color-
coded pa in t m a r k on t h e cr a n ksh a ft r ea r fla n ge.
Wh en r equ ir ed, u pper a n d lower bea r in g in ser t s of
differ en t sizes m a y be u sed a s a pa ir. A st a n da r d size
in ser t is som et im es u sed in com bin a t ion wit h a 0.025
m m (0.001 in ch ) u n der size in ser t t o r edu ce t h e clea r-
a n ce by 0.013 m m (0.0005 in ch ). N e v e r u s e a p a ir
o f be a rin g in s e rts w ith g re a te r th a n a 0.025 m m
(0.001 in c h ) d iffe re n c e in s ize (F ig . 20).
Fig. 20 Bearing Insert Pairs
2.5L ENGINE 9 - 23