BODY AS-PISTON 3220329 - Caterpillar

3176 Truck Engine (2YG1-Up);
3176 Truck Engine (7LG1-09753);
Challenger 75 (4CJ1-00479)Introduction
Some 3176 engines, used in the above applications, have experienced excessive oil leaks at the engine's timing gear housing.This instruction can be used as a guide to identify (isolate) the area of oil leakage and for the procedures, parts, and tools to repair.Parts and Tools Required
Failure Identification
Example of failure.A 3176 timing gear housing gasket failure can be identified by oil leaking down the front housing on to the ground and originating at the front housing to spacer block joint.
Not a failure. A seepage of oil at the joint is not considered a failure.Inspect Spacer Block For 9U5177 Insert(s) Installation
The spacer block must be inspected to determine if 9U5177 Insert(s) have been installed in the four bolt holes. The 9U5177 Insert(s) may have been installed during a previous failure or field update.9U5177 Insert(s) Have Been Installed
If the 9U5177 Insert(s) have been installed the 7X7973 Gasket Kit, 1011287 Gasket, 1011286 Plate and 6V2317 Bolt(s) must be installed:1. Install the gasket dry (without adhesives or liquid gasket material) with the non-beaded side of the gasket toward the spacer deck.2. Install plate on 9Y3592 Front Housing Cover using four 9M1974 Washer(s) and four 6V2317 Bolt(s).Tighten bolts to a torque of:* 28 7 N m (20.72 5.18 lb ft) The gasket is not symmetrical and is installed in only one position. Install the 1011287 Gasket with the non-beaded side toward the spacer deck.9U5177 Insert(s) Have Not Been Installed
If the 9U5177 Insert(s) have not been installed:
Spacer deck1. Drill four existing bolt holes (1) with an 8.33 mm (0.328 in) diameter drill bit to a depth of 25.5 1.6 mm (1.00 0.063 in).2. Tap each of the four holes with an 8T2789 Tap to a minimum depth of 18.3 mm (0.720 in).3. Install four 9U5177 Heli-Coil Insert(s) using an 8T2790 Installation Tool.Assemble Engine and Record Repair
Assemble EngineAssemble the engine with the new gaskets and Heli-Coil Inserts (if required).Record Repair
After engine assembly the repair must be recorded on the 9L6531 Engine Information Plate:* Stamp the letters CG next to the engine serial number on the SER. NO. portion of the plate.