Plastigage (Or Equivalent) In Place; Measuring Plastigage (Or Equivalent) - Pontiac Grand Prix Service Manual

6-26 1969
PONTIAC SERVICE MANUAL
Fig. 6-48 Plastigage (or equivalent) i n Place
2. Place a piece o f Plastigage, o r equivalent, the length of
bearing (parallel t o crankshaft), o n the crankpin or bearing
surface (Fig. 6-48). Install the cap and tighten cap bolts t o
33 Ib.
ft.
NOTE: Do not turn crankshaft with Plastigage, or
equivalent, in place.
3.
Remove bearing cap and using Plastigage scale, o r
equivalent, o n envelope measure w i d t h o f compressed
Plastigage, o r equivalent, before removing
it
f r o m the
crankpin o r bearing (Fig. 6-49). If bearing clearance is
between .0005" and .0028", clearance is satisfactory. If
clearance is more than .OM8", replace bearing w i t h next
size undersize bearing and recheck clearance. Bearings are
available i n .001", and .002" undersize.
4. Rotate the crankshaft after bearing adjustment to be
sure bearings are not tight.
5. Check connecting rod end clearance between
connecting rod cap and side of crankpin (Fig. 6-50).
Clearance should be .008"
-
.014". If clearance is more
than .0 14", replace connecting rod.
CONNECTING ROD AND PISTON ASSEM-
BLY-REMOVE AND REPLACE
REMOVE
1. Remove rocker
a r m
cover.
2. Disconnect fuel line and vacuum lines at carburetor.
3. Remove cylinder head, intake and exhaust mani-
folds as an assembly.
4. Remove ring ridge using a suitable ring ridge
5. Remove oil pan.
6. Check connecting rod and piston for cylinder
number identification and if necessary, mark them.
7. Remove bearing cap and install connecting rod bolt
guide set J 5239.
8. Carefully remove connecting rod and piston assem-
bly by pushing out with knurled handle of long guide.
CONNECTING ROD AND PISTON-DISASSEM-
BLE
NOTE: Use care at all times when handling and
servicing connecting r o h and pistons. To prevent
possible damage to these units, do not clamp rod or
piston in vise since they may become distorted. Do not
hllowpistons to stroke agai&t one another, against hard
objects or bench surfaces, since distortion of piston
contour or nicks in the soft aluminum material may
result.
Step A (Fig. 6-53)
1. Remove piston rings using J 802 1.
2. Install J 95 10-5 pilot on piston pin.
3. Place spring and J 9510-2 into base J 9510-1 and
index J 95 10-2 with piston pin.
4. Place spring and J 9510-2 as a guide, press piston
pin out approximately 1 /4".
remover
(Fig.
6-5 1).
-
-
-
-
Fig. 6-49 Measuring Plastigage (or Equivalent)