Product Overview

The shaft seal, OEM number A1643370359, is the front left differential and axle shaft seal fitted to the Mercedes-Benz ML-Class, covering both the W164 and W166 chassis, spanning production from 2002 through more recent model years. This is a small but essential sealing component, and given how widely the ML-Class platform has been sold and kept in long-term service, it's a steady, recurring part to stock.

Worn or failing units typically show up as a differential fluid leak near the axle shaft, low differential fluid level found during inspection, or a whining or grinding noise from the differential linked to inadequate lubrication. GSK Auto manufactures this shaft seal to OEM specification at our Ningbo, China facility, with every unit tested before packing. We supply at wholesale volume with low MOQ and support private label packaging, with our team available to confirm fitment before shipping.

Replacement OEM Numbers

Cross-Reference OEM Number

1643370359, 49374259, 594220

(Confirm against your VIN or chassis code before ordering - this is specifically the front left position, and left/right seals are sold and priced individually, so it's worth confirming side and quantity needs with your customer before shipping.)

What Is a Differential Shaft Seal?

Function: The shaft seal prevents differential fluid from leaking out around the axle shaft where it exits the differential housing, while also keeping dirt and contaminants from entering the differential.

Working Principle: The seal's alternating-twist lip design rides against the rotating axle shaft, maintaining a fluid-tight barrier as the shaft spins, with an additional dust lip helping block outside contamination from reaching the primary sealing surface.

Importance: A failing shaft seal allows differential fluid to escape, which can lead to low lubricant levels over time, and inadequate lubrication in a differential can cause accelerated wear on internal gears and bearings if left unaddressed.

Common Failures & Signs: Seal material hardening or cracking with age, reducing sealing effectiveness. Visible differential fluid leak near the axle shaft. Low differential fluid level discovered during routine inspection. Whining or grinding noise from the differential linked to inadequate lubrication.

Key Features

OEM-standard fitment - matches factory seal dimensions (75mm outer, 45mm inner, 9mm height) for the A1643370359 application.

Precision manufacturing - polyacrylate (ACM) material construction resists heat and differential fluid exposure.

Long service life - alternating-twist lip design maintains consistent sealing under rotation.

Excellent fitment - direct replacement, no modification required.

Corrosion resistance - dust lip design helps block outside contamination.

Reliable performance - consistent fluid retention matching factory specification.

Benefits

Importers - steady demand from a widely used, long-running Mercedes SUV platform.

Wholesalers - reliable repeat-order item across two chassis generations.

Repair Shops - OEM-spec fitment reduces comeback risk on differential service jobs.

Distributors - private label packaging available for building a branded catalog.

End Customers - protection against differential fluid loss and premature gear wear.

Packaging & Shipping

Standard export packaging, sized for a small sealing component. Customized packaging available for distributor branding. OEM-style and private label printing on request. Container loading handled directly, with mixed-SKU consolidation for smaller orders. Worldwide shipping to Europe, North America, South America, the Middle East, Africa, and Southeast Asia.

Why Choose GSK Auto

GSK Auto manufactures factory-direct, keeping pricing tied to production cost. This shaft seal is built to OEM specification and tested before packing. We support low MOQ, private label packaging, and worldwide shipping, with our technical team available to confirm fitment before you order.

Call to Action

Sourcing differential shaft seals for the Mercedes ML-Class? Contact GSK Auto for a wholesale quote, catalog, or OEM/private label cooperation.