Sierra 18-70958 Molded Hose, Transom to Oil Cooler, Replaces 32-96246A4/32-96246A1/32-96246, Fits MerCruiser 350 MAG Alpha and 5.7L Alpha

The Sierra 18-70958 is a molded hose engineered to connect the transom to the oil cooler on a range of MerCruiser stern drive engines. It is built from marine-grade plastic material in white and is designed as a direct fit for the specific routing and bend pattern required between the transom fitting and the oil cooler, so it seats correctly without kinking or needing to be forced into place. Because engine bay hose runs are exposed to heat, oil, and constant vibration, a molded hose that matches the original bend geometry helps prevent chafing and premature cracking that can occur with generic straight hose cut to fit.

This hose is a replacement for the OEM numbers 32-96246A4, 32-96246A1, and 32-96246, and it fits a wide range of MerCruiser engines and drive combinations including the MC898, MC200, MC228, MC230, MC260, 300 Tempest MR, MC320 EFI, 350 MAG Alpha, 5.7L Alpha, 5.7LX and 5.7LX EFI Alpha, 454 MAG Alpha, and the 5.0L and 5.0LX Alpha. Always confirm the year and model of your engine against the fitment list before ordering to ensure the correct transom-to-oil-cooler hose for your specific setup.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-70958
• Product Type: Molded Hose
• Application: Transom to oil cooler
• Material: Plastic
• Color: White
• Weight: 1.15 pounds
• OEM Cross Reference: 32-96246A4, 32-96246A1, 32-96246
• UPC: 808282265724

Fitment

• MerCruiser MC898 (1983-84)
• MerCruiser MC200 (1985-87)
• MerCruiser MC228 (1982-84)
• MerCruiser MC230 (1985-87)
• MerCruiser 5.0L & 5.0LX Alpha (1988-95)
• MerCruiser MC260 (1983-87)
• MerCruiser 300 Tempest MR (1985-86)
• MerCruiser MC320 EFI (1987-89)
• MerCruiser 350 MAG Alpha (1986-96)
• MerCruiser 5.7L Alpha (1988-96)
• MerCruiser 5.7LX & 5.7LX EFI Alpha (1996)
• MerCruiser 454 MAG Alpha (1986-88)

Replaces (OEM)

• 32-96246A4
• 32-96246A1
• 32-96246

Frequently Asked Questions

What does the Sierra 18-70958 hose connect on a MerCruiser engine? The Sierra 18-70958 is a molded hose that routes from the transom fitting to the oil cooler on applicable MerCruiser stern drive engines.

Which MerCruiser engines fit part number 18-70958? It fits the MC898 (1983-84), MC200 (1985-87), MC228 (1982-84), MC230 (1985-87), 5.0L & 5.0LX Alpha (1988-95), MC260 (1983-87), 300 Tempest MR (1985-86), MC320 EFI (1987-89), 350 MAG Alpha (1986-96), 5.7L Alpha (1988-96), 5.7LX & 5.7LX EFI Alpha (1996), and 454 MAG Alpha (1986-88).

Is 18-70958 the same as OEM hose 32-96246? Yes, the Sierra 18-70958 molded hose is the direct replacement for OEM numbers 32-96246A4, 32-96246A1, and 32-96246.

What is the 18-70958 hose made of? This transom-to-oil-cooler hose is made of plastic material and is white in color.

How much does the 18-70958 hose weigh? The Sierra 18-70958 molded hose weighs 1.15 pounds.

Will a generic straight hose work in place of the 18-70958? A generic straight length of hose can be cut to approximate the route, but the 18-70958 is molded to the original transom-to-oil-cooler bend pattern, which reduces the risk of kinking or chafing that a straight-cut substitute can develop over time.

Does the 18-70958 hose come with clamps or fittings? The Sierra 18-70958 is supplied as the molded hose itself for the transom-to-oil-cooler run; it does not include a listed set of clamps or fittings.

Is the Sierra 18-70958 a genuine or aftermarket part? The 18-70958 is a Sierra-manufactured aftermarket replacement hose engineered to replace the OEM 32-96246 series parts, built to the original fit and routing.

Can I use 18-70958 on a 454 MAG Alpha engine? Yes, the 18-70958 transom-to-oil-cooler hose is listed to fit the 454 MAG Alpha (1986-88).

Does 18-70958 fit both carbureted and EFI MerCruiser models? Yes, the fitment list for 18-70958 includes both carbureted models such as the 350 MAG Alpha and EFI models such as the MC320 EFI and 5.7LX EFI Alpha (1996).