Executing a full engine overhaul or block reconditioning on a Caterpillar 3304 powerplant? Follow this step-by-step professional workshop procedure to clean housing bores, align oil passages, and drive balance shaft bearings cleanly using the M20060-41 adaptor set and driver bar. Why Cocked Bushings & Blocked Oil Holes Destroy 3304 Engines The balance shafts on a Caterpillar 3304 rotate at double engine speed to cancel out second-order harmonic vibrations. Because of these high rotational speeds, the balance shaft journal bearings require a continuous, uninterrupted film of pressurized oil supplied directly through the cast-iron block passages. When installing new sleeve bearings, if a technician attempts to drive them into the block using generic socket extensions or unguided punches, the driving force is concentrated unevenly. The soft babbitt-lined steel shell cocks in the housing, gouging the precision-bored block wall. Even more dangerous, an unguided driver allows the bearing to rotate slightly during insertion, misaligning the oil feed hole. When the engine is fired up, oil pressure fails to reach the spinning balance shaft journal, leading to instant metal-on-metal friction, bearing spun failures, and total engine destruction. Utilizing a dedicated pilot driver collar like the M20060-41 locks the bearing completely parallel while maintaining strict rotational orientation relative to the block oil port. The 5-Step Balance Shaft Bearing Installation Protocol Block Bore Inspection & Triage: Remove old balance shaft bearings using an appropriate extractor tool. Thoroughly clean all varnish, metal filings, and old oil sludge off the engine block balance shaft housing bores using solvent and a non-abrasive brush. Verify that the cast-iron oil feed passages are 100% clear of debris. Assemble M20060-41 Adaptor onto Driver Bar: Attach the M20060-41 pilot adaptor collar securely onto the appropriate length service driver bar (M20060-2455 24″ or 55″ bar depending on bore depth position in the block). Stage & Index the Balance Shaft Bearing: Slide the fresh CAT 3304 balance shaft bearing onto the M20060-41 adaptor collar until it seats squarely against the tool shoulder. *CRITICAL: Visually index the oil supply hole in the bearing to line up 100% dead-center with the oil feed gallery opening inside the engine block bore.* Execute Controlled Parallel Driving: Insert the driver bar and staged bearing assembly into the block bore. Using a dead-blow driver mallet or mechanical press setup, apply smooth, centered, parallel strikes to the driver bar end. Drive the bearing steadily into the housing bore until the tool depth stop indicates exact OEM location. Verify Oil Port Registration & Journal Clearance: Withdraw the driver tool and visually inspect the installed bearing. Verify through the oil hole using a bore scope or light probe that the oil passage is 100% open and aligned. Apply clean assembly lube to the bearing ID before installing the balance shaft. PRO-TECH OIL HOLE ALIGNMENT MANDATE: Always double-check oil hole alignment both BEFORE and AFTER driving the balance shaft bearing into the CAT 3304 block! A bearing driven in straight but rotated 180° out of phase will completely block oil flow, leading to immediate journal seizure upon initial engine startup. Always verify 100% visual oil passage alignment! Precision Machined Steel Adaptor. Protect Your Caterpillar 3304 Engine Block. Get the M20060-41 Adaptor Kit Now
