Mack E7 Service Manual page 180

5-101.bk Page 22 Friday, March 17, 2006 11:05 AM
Refer to Figure 6-22.
1. Use Plastigage to check the main bearing
clearance. Check each bearing, one at a
time, by placing a piece of Plastigage on the
journal and tightening the cap in place. The
bearing clearance is determined by
measuring the width of the crushed
Plastigage with the supplied gauge.
2. Place a section of Plastigage (2) on the
journal to be checked and assemble main
bearing cap (1) to cylinder block.
3. Apply a light coat of oil on threads of the
bearing cap capscrews and secure cap.
4. Torque capscrews to 210 lb-ft
(285 N m) using torque wrench J 24407 or
equivalent. The Plastigage strip will be
crushed between the bearing insert (3) and
the crankshaft journal (4).
1
Figure 6-22 — Checking Running Clearance
with Plastigage
1. Main bearing cap
2. Plastigage
Page 6-22
200 ENGINE ASSEMBLY
2
3
4
200339a
3. Bearing insert
4. Crankshaft journal
5. Remove capscrews and cap, and check the
bearing running clearance.
6. Check width of the Plastigage using a
Plastigage width chart. After measuring
width, remove Plastigage from bearing.
7. If clearance is not within specification,
correct as required. Be sure to use the
correct size bearing.
8. If clearance is less than specified, also
check behind bearing for dirt, chips or burrs
which would prevent the bearing from
seating properly.
9. Reposition cap on journal. Lubricate
capscrews with clean EO-L specification
engine oil. Lubricate and install the bearing
cap buttress capscrews as required, and
leave finger tight. Install the bearing cap
capscrews and torque to 210 lb-ft (285 N m)
using torque wrench J 24407 or equivalent.
Refer to Figure 6-23.
There are two buttress capscrew dimensions:
LH side 2, 3, 5, 6; RH side 5, 6 (6 each) are
80 mm long (1)
RH side FRT 2 and 3, engine bulkhead
(2 each) are 110 mm long (2)