ELONN LS Rear Main Seal Alignment Tool for GM Gen III & IV LS Engines — Billet Aluminium, Centres Seal

ELONN's LS Rear Main Seal Alignment Tool precisely centers and installs the rear main seal on GM Gen III and IV LS-series engines to prevent leaks and ensure correct seal seating.

When rebuilding or servicing GM LS engines, accurate rear seal alignment is critical to avoid oil leaks and premature seal failure. The ELONN LS Rear Main Seal Alignment Tool is a purpose-built billet-aluminum fixture engineered for direct fitment to a wide range of Gen III and Gen IV LS engines, including 4.8, 5.3, 5.7, 6.0, 6.2, 7.0 and the common LS1, LS2, LS3, LS6, L99, LS4, LS9, LSA, LQ4, LQ9, L76, and L92 variants. It helps both professional engine builders and home mechanics install the rear main cover and seal concentrically with the crank balancer hub and the sealing surface, reducing rework and leakage risk.

How does this tool improve rear main seal installation accuracy?

The ELONN alignment tool acts as a precise locating gauge that centers the rear cover and provides a uniform reference to press the seal into place. By matching the factory sealing geometry, it eliminates guesswork and uneven seating that commonly causes leaks.

• Centers cover concentric to the crank balancer hub for true alignment
• Maintains correct seal depth and orientation during installation
• Reduces the chance of seal pinching or twisting
• Speeds up installation while lowering rework and inspection time

What engine models and applications are supported?

This fixture is designed specifically for GM LS-series Gen III and Gen IV engines and fits a broad range of displacements and model codes used in factory and aftermarket builds. It suits engine rebuilds, timing cover replacements, and any service requiring rear seal removal and reinstallation.

• Compatible with 4.8, 5.3, 5.7, 6.0, 6.2 and 7.0 liter LS engines
• Works with LS1, LS2, LS3, LS6, L99, LS4, LS9, LSA
• Also fits iron-block variants LQ4, LQ9, L76, L92
• Suitable for stock rebuilds, performance swaps and race prep

What is the tool made of and what does the kit include?

Durability and repeatable precision are achieved through CNC-machined billet aluminum construction that resists wear and holds alignment over repeated use. The package is intentionally simple so it integrates easily into existing engine assembly workflows.

• High-quality billet aluminum body for long service life
• Precision-machined locating features for reliable centering
• Includes one rear cover billet alignment tool — ready to use
• Compact, lightweight design for shop or mobile use

How does using the tool affect long-term reliability?

Proper initial installation is a major factor in preventing oil leaks later. By ensuring the rear main seal seats true and evenly the first time, the ELONN tool reduces the likelihood of seal failure due to misalignment, uneven wear, or improper seating depth.

• Promotes even seal compression down the full circumference
• Minimizes edge folding and contact irregularities that cause leaks
• Helps maintain factory tolerances across rebuilds and swaps
• Saves time diagnosing leaks that stem from installation errors

Who is this for: The ELONN LS Rear Main Seal Alignment Tool is intended for professional engine builders, automotive technicians, performance shops and experienced DIYers working on GM LS-series Gen III and Gen IV engines. If you perform seal replacement, timing cover service or full engine rebuilds and want predictable, leak-free results, this compact billet tool streamlines the job and improves outcome reliability.