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Removing or replacing the camshaft on a heavy-duty Mack E6, E7, or E9 diesel engine? Attempting to hold heavy roller lifters and tappets out of the way using makeshift wire, magnets, or tape is a high-risk gamble. Unsecured roller lifters can drop back down into the engine block during camshaft slide-out, jamming against cam lobes, gouging precision lifter bores, or dropping deep into the oil pan. A chipped roller face or scratched lifter bore leads to rapid cam lobe wipeout, metal debris in the oiling system, and catastrophic engine failure. Engineered for heavy-duty Mack truck technicians and engine rebuild facilities as a direct USA-made replacement for OEM tool J-37720-C (J-37720C), the ATC37720 Roller Lifter Tappet Holding Kit features a two-piece sectional rod architecture specifically designed to clear tight cab clearances (such as Mack RD cabs) and suspend all lifters securely during camshaft extraction and installation.

The Critical Physics of Mack Roller Lifter Retention & In-Cab Clearance Engineering

Heavy-duty Mack E6, E7, and high-horsepower E9 V8 diesel engines feature heavy roller lifters that ride directly on camshaft lobes to translate rotational lift into pushrod motion. During top-end overhauls or camshaft replacement, the camshaft must be slid horizontally out through the front of the gear case. However, because gravity constantly pulls roller lifters downward into the camshaft's path, all lifters must be elevated clear of the cam lobes before the shaft can move. In tight engine bays—particularly Mack RD cab configurations—working space directly above the pushrod openings is extremely restricted by firewall overhangs, making long single-piece holding rods impossible to insert. The ATC37720 kit solves both structural challenges. Manufactured with precision two-piece threaded rods, technicians screw the rod sections together as they lower them into the pushrod openings until they contact the tappet base. Once the lifter is pulled up past the cam lobe profile, an adjustable high-tension retention grommet is slid down the shaft flush against the deck face, locking the lifter in a suspended position. This rigid, positive mechanical hold ensures 100% clearance across every cylinder, allowing the camshaft to glide out smoothly without striking roller faces or dropping components into the crankcase.

• Targeted Mack E6, E7 & E9 Engine Coverage – Purpose-built specifically for roller lifter and tappet service on Mack E6, E7, and heavy-duty E9 diesel engine platforms.
• Direct OEM Factory Tool Interchange – Precision-machined functional replacement for Kent-Moore / Mack OEM specialty tool part number **J-37720-C** (ATC37720 / J-37720C / ATC 37720C).
• Modular Two-Piece Threaded Rod System – Specially engineered for tight-fit Mack RD cab configurations and tight firewall overhangs where full-length rods cannot clear.
• Positive Mechanical Grommet Locking – High-friction retention grommets slide down the polished shafts to hold lifters suspended indefinitely above cam lobes.
• Heavy-Duty Commercial Grade Steel Construction – Substantial 7.00 lbs solid alloy steel build engineered for continuous daily service in commercial repair shops and fleet overhaul bays.

Stop Juggling Lifters with Magnets. Command Total Mack Camshaft Service Precision.

The ATC37720 For Mack E6 E7 E9 Roller Lifter Tappet Holding Kit J-37720C is an essential capital asset for commercial truck repair centers, Mack dealership service bays, fleet maintenance facilities, and heavy diesel rebuilders. Prevent dropped lifters, protect precision cam lobes, and perform camshaft service with complete mechanical authority using Apex tools.

Technical Specifications

Technical Metric	Value / Fitment Reference Guidelines
Target Engine Platforms	Mack E6, Mack E7, and Mack E9 Heavy-Duty Diesel Engines
Primary Operational Function	Suspending roller lifters/tappets during camshaft removal and installation
Specialty Tool Cross Reference	Direct replacement for Mack / Kent-Moore OEM J-37720-C (ATC37720 / J-37720C)
Part / Model Reference Number	ATC37720 (ATC 37720 / ATC37720C)
Special Architectural Features	Two-piece threaded rods for low-clearance Mack RD cabs; friction lock grommets
Total Package Shipping Weight	7.00 lbs (Complete professional multi-cylinder service kit)

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