Front Upper Lateral Control Arm For Mercedes GL GLS X166 2012-2019 A1663301707 A1663301807

Q1: Which vehicles does this fit? Mercedes-Benz GL-Class (X166, 2012–2015) / GLS-Class (X166, 2015–2019) per the supplier table. European catalog data also lists GLE (2015–2019) and M-Class (2011–2015). Confirm the exact model and year by VIN.

Q2: Is the left/right side interchangeable? No — this is a mirror pair: Left A1663301707 and Right A1663301807 are side-specific and NOT interchangeable. Order by side.

Q3: What is this arm exactly? The front upper lateral control arm / track control arm — position: Front Axle, Upper (catalog: "Front Axle Left/Right, Upper"). Aluminium construction, with ball joint (catalog-verified), approx. 1.5 kg. No electrical damping — a plain mechanical suspension linkage.

Q4: Are there other numbers in this family? The catalog OE list contains only the A-prefix format variants of the same arm — no further superseded numbers. Order by the exact OE number; confirm by VIN.

Q5: Is this the upper arm (not the lower)? Yes — this is the upper control arm of the X166 front axle (aluminium, with ball joint — distinctly lighter than the aluminium lower-arm family 166 330 01 07 / 02 07, which has no ball joint). Verify the position against the original unit by VIN.

Q6: Do I need to replace both sides at the same time? Same-axle pair replacement is strongly recommended; an old arm on the other side causes uneven geometry and tire wear.

Q7: What should I pay attention to during installation? Tighten all bolts to the workshop-manual torque specifications with the suspension under load; after installation perform a wheel alignment (camber/caster/toe) and check the ride height per workshop manual.

Q8: Warranty policy and shipping damage? 18-month warranty under normal use. For shipping damage, inspect within 48 hours of receipt and send photos/video — the seller arranges a replacement.

Q9: Service life and maintenance? Depends on road conditions and climate. Check the bush for cracks and the ball joint for play during routine service; replace the arm if bush wear, play or crash damage is found.

Q10: Are aftermarket alternatives available? The interchange list for these OE numbers is available on request. Order by the exact OE number and confirm the model/year and side by VIN.