Connecting Rod Nut - Torque Revision
89AMCjeep04Models
1989 B2 With 1.5L Engine
Subject
1.5L Engine Connecting Rod Nut Torque Revision
Index
ENGINE
Date
June 5, 1989
No.
09-54-89
(C09-10)
P-2167
BODY CODE LEGEND
B2 - SUMMIT 4-DOOR
SERVICE MANUAL REVISION
The connecting rod nut tightening procedure and torque value for the 1.5L engine has been changed. This change was effective August 22, 1988 beginning with engine number KB6800. In addition, several other changes to reduce crankshaft/connecting rod system weight entered production at the same time. Following are the changes that will affect engine servicing.
ENGINE - Specifications:
Piston and Connecting Rod:
Please permanently affix the revised pages for the Colt/Summit Service Manual (Publication No. 81-270-9011, Pages 9-17 and 9-66) enclosed with this Technical Service Bulletin.
Figure 1:
1. The crankshaft counter weights have been reduced in size and shape and the connecting rod pin width has been reduced from 22 mm to 20 mm. Figure 1.
Figure 2:
2. The connecting rod dimensions and identification marking has been changed. Figure 2.
Figure 3:
3. The connecting rod bolt and nut thread size has been changed from a MB x 1.0 to M7 x 0.75. Figure 3.
Figure 4:
4. The connecting rod bearing width has been reduced from 17.5 mm to 15.5 mm. Figure 4.
REVISED PROCEDURE
This procedure applies only to engine number KB6800 and later.
1. Before installing the connecting rod cap, check the rod bolt for damaged threads by running the connecting rod cap nut (M7 x 0.75) the full length of the threads with your fingers only. If the nut does not run freely, replace the bolt.
2. Oil the connecting rod threads with engine oil, install the rod cap and cap nuts finger tight only.
3. Alternately pre-tighten the cap nuts to 20 N-m (14.5 ft.lbs.).
4 Loosen both cap nuts to "0" torque.
5. Tighten cap nuts to 20 N-m (14.5 ft.lbs.) torque, after the nuts have been torqued, tighten the nuts an additional 1/4 (90~) turn.
These new parts are interchangeable with earlier engine only when crankshaft, connecting rods, connecting rod bolts and nuts and connecting rod bearings are replaced as a set.
POLICY: Information only.