The EN-47680 Crankshaft Stopper installs in place of the starter to securely lock the flywheel ring gear, preventing crankshaft rotation on Isuzu diesel engines during timing, flywheel, balancer, or front seal service—ensures precise alignment, safe torque application, and no movement-related damage.

The High Costs of Uncontrolled Crankshaft Rotation on Isuzu Engines

Without a proper crankshaft stopper, flywheel rotation during timing, seal, or balancer work causes misalignment, inaccurate torque, stripped threads, bent components, or sudden movement hazards—leading to rework or major failure.

• Timing misalignment – $1,500–$5,000 valve train / injector damage
• Front seal / balancer improper install – $800–$2,500 repeat leak repair
• Flywheel bolt stripping / breakage – $600–$2,000 flywheel & bolt set
• Crankshaft / bearing damage – $2,000–$8,000 machining or crank replacement
• Safety incident / injury – $5,000–$40,000+ medical & downtime
• Extended labor & truck downtime — 8–30 hours extra at $150–$350/hr

What is the EN-47680 Crankshaft Stopper?

The EN-47680 Crankshaft Stopper (ATC EN-47680) is a heavy-duty holding tool that replaces the starter motor and engages the flywheel ring gear teeth to completely immobilize the crankshaft on Isuzu diesel engines.

Built for professional truck shops, fleets, and rebuild facilities, it provides rock-solid restraint for timing-critical and torque-heavy jobs on 4JJ1, 4HK1, 6HK1, and similar Isuzu platforms—improves accuracy, safety, and efficiency.

Complete Tool Specifications & Isuzu Compatibility

Professional Features & Service Benefits

Economic Impact: EN-47680 ROI for Shops

Scenario	Cost Impact
EN-47680 secure hold	Tool investment – $150.00
Timing misalignment repair	$1,500–$5,000
Front seal / balancer rework	$800–$2,500
Flywheel / bolt damage	$600–$2,000
Crank / bearing damage	$2,000–$8,000
Total uncontrolled rotation cost	$4,900–$17,500 per incident
EN-47680 ROI (first prevention)	33–117X return on investment

When Isuzu Techs & Fleets Choose EN-47680

• Isuzu 4JJ1 / 4HK1 / 6HK1 crankshaft holding
• Front crankshaft seal & balancer service
• Flywheel removal & installation
• Cam / injection timing adjustments
• Isuzu NPR / NQR / heavy truck maintenance
• Precise torque & alignment jobs
• Safe high-load engine work

Why Diesel Pros Rely on EN-47680

Isuzu specialists choose the EN-47680 for its positive ring gear engagement, zero-slip hold, and ability to eliminate $4.9K–$17.5K in per-job damage from rotation errors. It delivers controlled, accurate service every time.

From NPR fleets to rebuild shops, this stopper keeps jobs precise and safe.

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