ARMY TM 9-2815-255-24
AIR FORCE TO 38G1-95-2
MARINE CORPS TM 2815-24/4
If oversized balancer shaft bushings are used, engine block must be line bored.
Line bore engine block to specification listed below. Refer to FIGURE 3-114 for References A through E.
Reference all line boring dimensions from front left dowel pin (E).
A.. 1.653 to 1.655 inches (41.985 to 42.035 mm)
B.. 10.157 to 10.159 inches (257.985to258.035 mm)
C.. 2.558 to 2.560 inches (64.986 to 65.036)
D.. 1.7015 to 1.7025 inches (43.237 to 43.263 mm)
Make a chamfer 20 to 25 degrees x 0.060 inch (1.5 mm toward front of engine for front and middle bores and
toward rear for rear bore to make bushing installation easier.
Check bores for smoothness after machining.
Make sure oil hole In bushing (16, FIGURE 3-108) Is aligned with oil passage In block for proper
bushing and journal lubrication.
If removed, use balancer shaft bushing driver (JD-249) to drive new bushings (16) into engine block.
Adequate bushing-to-balancer shaft clearance exists, if shaft can be rotated by hand with a
slight-to-moderate drag. It is not necessary to hone bushing to obtain specified oil clearance.
Excessive clearance can result in shaft seizure.
If gear (11 or 12) was removed, install as follows:
Install key (15) in slot on shaft.
Position balancer shaft (13 or 14) in balancer shaft holding tool (JD-247).
Install thrust plate (9 or 10) and gear (11 or 12) on balancer shaft. Be sure timing mark on gear faces away
from balancer shaft.
Press gear onto shaft with a tube-type driver and arbor press. Press gear until a clearance of 0.002 to
0.008 inch (0.005 to 0.20 mm) exists between thrust plate and gear/shoulder.
Make sure engine is at TDC (No. 1 piston on compression stroke), with timing pin engaged in flywheel.