GMC S Series 1994, Repair Manual

Page: 339 / 919

Method “B”
1. Clean and install the bearing inserts, and
crankshaft into block.
2. Place a piece of gaging plastic across the
entire
bearing width.
3. Seat the bearing cap carefully by tapping it lightly
with a suitable tool.
NOTICE:
In order to prevent the possibility of
cylinder block and/or main bearing cap damage,
the main bearing caps are to be tapped into their
cylinder block cavity using a brass or leather
mallet before attaching bolts are installed. Do not
use attaching bolts to pull main bearing caps into
their seats. Failure to observe this information
may damage a cylinder block or bearing cap.
• Connecting rod nuts to 52 N*m (38 lbs. ft.).
• Main bearing cup bolts to 95 N*m (70 lbs. ft.).
m Important
• Do not
rotate the crankshaft.
4. Remove the bearing cap, leaving the gaging
plastic in place. It does
not
matter whether the
gaging plastic adheres to the journal or to the
bearing cap.
Measure the flattened gaging plastic at its
widest
point
with the scale printed on the gaging plastic
package. Refer to Figure 29.
• If clearance obtained meets specification, the
bearing size used for measurement is correct.
• If clearance obtained does not meet the
specification, choose a service bearing that
will correct the clearance and meet the
specification. If the proper bearings are
unavailable, the crankshaft must be replaced.
NOTICE:
Bearing inserts must not be shimmed,
scraped or filed. Do not touch the bearing surface
of the insert with the bare fingers. Skin oil and
acids will each the bearing surface.
6. Remove all traces of the gaging plastic after
measuring.
|-»4-| Install or Connect
|~y| Important
• Make sure the bearing cap bolt holes and the
cap mating surfaces are clean and dry.
1. Dip bearing cap bolts in clean engine oil.
2. Lubricate the bearing surface with engine oil
supplement, GM P/N 1052368 or equivalent.
3. Crankshaft or connecting rod.
NOTICE:
Avoid damage to the crankshaft
journal. Use connecting rod stud protectors or
guide pins.
4. Bearing cap. Tap gently into place with a brass or
leather mallet.
NOTICE:
In order to prevent the possibility of
cylinder block and/or main bearing cap damage,
the main bearing caps are to be tapped into their
cylinder block cavity using a brass or leather
mallet before attaching bolts are installed. Do not
use attaching bolts to pull main bearing caps into
their seats. Failure to observe this information
may damage a cylinder block or bearing cap.
Tighten
• Connecting rod nuts to 52 N*m (38 lbs. ft.).
• Main bearing- cap bolts to 95 N*m (70 lbs. ft.).
5. Seat the crankshaft thrust bearing, by forcing
crankshaft fully rearward to align all bearing
caps, then force the crankshaft fully forward to
align the rear thrust bearing surfaces. Refer to
Figure 30.
Tighten
Main bearing cap bolts to 95 N*m (70 lbs. ft.).
Pry the connecting rods back and forth and check
for binding. If necessary loosen and re-tighten the
bearing cap.