Crankshaft Balancer/Head Bolt/Torque - Revised
File in Section: 6 - EngineBulletin No.: 47-61-31
Date: November, 1994
Subject:
Revised Crankshaft Balancer/Cylinder Head Bolt Usage and Torque Specifications
Models:
1982-85 Cadillac Fleetwood Brougham
1982-93 Cadillac Eldorado, Seville
1982-95 Cadillac DeVille
1985-93 Cadillac Sixty Special/Fleetwood
1987-92 Cadillac Allante
with 4.1L, 4.5L or 4.9L Engines (VINs 3, 5, 7, 8, B - RPOs LT8, LC7, LR6, LQ6, LW2, L26)
Crankshaft balancer and cylinder head torque specifications are now revised. Specifications and new service procedures are defined below.
Crankshaft Balancer Bolt
The new crankshaft balancer torque specification is 160 Nm (118 lb.ft.). This torque specification applies to all engines equipped with a WASHER FACE BOLT (see Figure 1) along with a separate washer.
This washer face bolt replaces the PREVIOUS STANDARD HEAD BOLT (see Figure 2) and separate washer arrangement which has a torque specification of 95 Nm (70 lb.ft.).
Whenever servicing a crankshaft balancer held by a washer face bolt, use the revised 160 Nm (118 lb.ft.) torque specification.
If servicing a crankshaft balancer with the standard head bolt, use the 95 Nm (70 lb.ft.) torque specification.
Note:
Early 1988 4.5L and all 4.1L original equipment engines do not have a crankshaft balancer retaining bolt.
Important:
Long and short-block replacement engines, including the transverse 4.1L V-8 built AFTER JUNE OF 1990 are equipped with the washer face bolt and should use the 160 Nm (118 lb.ft.) torque specification. Replacement transverse engines built between November 1987 and June 1990 use the standard head bolt and use the 95 Nm (70 lb.ft.) torque specification.
Cylinder Head
The cylinder head bolt torque sequence for 4.1L, 4.5L and 4.9L engines is revised. Whenever servicing the cylinder heads of these engines. measure the thread length of the inboard and outboard cylinder head bolts to determine the proper torque specification.
To determine thread length, use a millimeter scale and measure from the first thread (closest to the bolt head) to the end of the bolt. Refer to the chart below for bolt application and usage.
Important:
Taper grind (see Figure 5) the end of bolts with thread lengths of 39 to 41 mm. Without taper grinding, these bolts may "bottom out" in the engine block before proper torque is achieved, resulting in improper sealing between the cylinder head and block.
Important:
When taper grinding a bolt or stud, be sure to install an M12 x 1.75 nut beyond the grinding point. When grinding is complete, removing the nut will clean the threads at tip of the bolt and ease installation.
Torque Sequence and Specifications
Please update Section 6A of your Service Manual as appropriate.