Connecting Rod Bearings-Remove And Replace; Removing Upper Rear Main Oil Seal; Tool For Removing Upper Half Of Main Bearing - Pontiac Grand Prix Service Manual

SIX CYLINDE
1 R
ENGINE
6-25
Fig. 6-46 Removing Upper Rear Main Oil Seal
PLASTIGAGE (OR EQUIVALENT) METHOD OF
DETERMINING MAIN BEARING CLEARANCE
1. Place a .002" brass shim between the crankshaft
journal and lower bearing in each beqing cap next to
that being checked. .Tighten all cap bolts to 100 lb.
ft.
This causes the crankshaft to be forced against the
upper bearing and insures an accurate measurement of
total clearance.
2. Remove the bearing cap of bearing to be checked.
Wipe bearing and journal free of oil.
3. Place a piece of Plastigage, the length of bearing
(parallel to crankshaft), on journal or bearing surface
(Fig. 6-48). Install cap and tighten cap bolts to proper
torque.
NOTE: Do n o t turn crankshaft with Plastigage, o r
equivalent, in place.
4. Remove bearing cap and using Plastigage, or equivalent,
scale on envelope measure width of compressed Plastigage,
or equivalent, before removing i t from the bearing or
journal (Fig. 6-49). If bearing clearance is between .0003"
and
-002".
the clearance is satisfactory. I f clearance is
more than
.002",
replace bearing with next undersize
bearing and recheck clearance. Bearings are available in
standard size .001" and .002" undersize.
5. Install a new rear main bearing oil seal in cylinder
block and main bearing cap if rear main bearing was
checked and/or replaced.
6. Check crankshaft end play with feeler gauge at No.
7 main bearing (Fig. 6-52). If end play is over .006,
replace bearing.
CONNECTING ROD BEARINGS-REMOVE AND
REPLACE
Connecting rod bearing inserts are available in
standard size and undersizes of .001 and .002". These
bearings are not shimmed and when clearances
become excessive the next undersized bearing insert
should be used. DO NOT FILE ROD OR ROD CAPS.
REMOVE
1. Remove oil pan. (See Oil Pan-Remove and
Replace.)
2. Rotate crankshaft as necessary to bring crankpin
carrying bearing to be replaced straight toward bottom
of block.
3. Remove bearing cap.
4. Install connecting rod bolt guide set J 5239 on
connecting rod bolts. Push piston and rod assembly up
far enough to remove upper bearing.
5. Remove bearings from cap and rod.
6. Inspect crankpin for damage, out-of-round and
taper.
REPLACE
1. Reassemble cap and rod with new bearings and check
clearance with Plastigage, or equivalent, as outlined below.
2. Install oil pan using new gaskets and seals.
PLASTIGAGE METHOD (OR EQUIVALENT) OF
DETERMINING CONNECTING ROD BEARING
CLEARANCE
1. Remove cap of bearing to be checked. Wipe the
bearing and the crankpin free of oil.
Fig. 6-47 Tool For Removing Upper Half of Main
Bearing