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Required for fitment review to confirm compatibility.
The OBR Mercury V8 Pro XS TorqueMaster lower unit is a remanufactured 20-inch gearcase for selected 200–300 HP four-stroke applications requiring a 1.75:1 gear ratio. OBR SKU ME-G8-10-R replaces Mercury OEM references 8M0142316 and 8M0244527.
Mercury uses the TorqueMaster gearcase on select V8 Pro XS models. Because engines within the same horsepower range can use different gearcases, horsepower or model year alone cannot confirm fitment.
Before ordering, match the complete engine serial number, original OEM number, TorqueMaster gearcase family, 20-inch shaft length, gear ratio and rotation. This is an OBR-remanufactured replacement assembly, not a new Mercury OEM lower unit.
V8 Performance Optimized: Precision-built to manage the massive low-end torque of the 200HP to 300HP Pro XS V8 platform.
TorqueMaster Geometry: Advanced housing design for enhanced high-speed tracking and reduced propeller blow-out.
Ready for Competition: Rigorously tested to ensure smooth shifting and maximum power transfer under extreme loads.
Proper lubricant, shift adjustment and break-in are essential. OBR instructs owners not to exceed 75% throttle during the first five hours and not to maintain full throttle for extended periods during the next five hours. Review the complete procedure before operation.
| Specification | Mercury V8 Pro XS TorqueMaster Lower Unit | 20-Inch |
|---|---|
| Remanufacturer | OBR Parts & Marine |
| Compatible Engine Make | Mercury / Mariner |
| Product Family | TorqueMaster replacement gearcase |
| Condition | Remanufactured |
| OBR SKU | ME-G8-10-R |
| OEM Cross-References | 8M0142316; 8M0244527 |
| Engine Family | Selected Mercury 4.6L V8 Pro XS four-stroke applications |
| Horsepower | 200, 225, 250 and 300 HP within OBR's published 200–300 HP range; exact serial verification required |
| Gearcase | TorqueMaster |
| Shaft Length | 20-inch L |
| Gear Ratio | 1.75:1 |
| Propeller-Shaft Diameter | 1.25 inches for the Mercury TorqueMaster system on select V8 models |
| Gear Oil | Not included; OBR gearcases ship without oil |
| Warranty | OBR two-year limited gearcase warranty, subject to full terms |
| Major Exclusions | Do not substitute for a 5.44-inch gearcase, Sport Master, Verado, SeaPro, XL or XXL application without exact supplier-confirmed fitment |
Mercury’s 4.6L V8 Pro XS family can use different gearcase configurations, so the engine’s horsepower badge is not enough to select a replacement lower unit. Start with the complete serial number on the engine identification label. Then find the OEM number or other identification from the original gearcase and confirm that the housing is a TorqueMaster—not a 5.44-inch standard gearcase or Sport Master.
For OBR SKU ME-G8-10-R, the published configuration is a remanufactured 20-inch TorqueMaster lower unit with a 1.75:1 gear ratio for the supplier’s listed 200–300 HP V8 Pro XS four-stroke range. The OEM cross-references are 8M0142316 and 8M0244527.
Before purchasing, also confirm rotation, vertical and propeller-shaft spline requirements, and whether any model-specific midsection or control configuration affects the application. If any identifier differs, stop and request a fitment review. Supply the full engine serial number, original gearcase number and clear photos of the existing housing and identification markings.
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The product information made it easy to confirm the correct TorqueMaster lower unit configuration needed for a Mercury V8 Pro XS 250 HP application. The 1.75:1 gear ratio, 20-inch shaft length, and cambered skeg details were clearly explained. Buyers should verify their gear ratio and shaft length instead of ordering by horsepower alone.
I appreciated that the V8 Pro XS TorqueMaster options were clearly distinguished from standard 4.8-inch gearcases. The 20-inch shaft, 1.75:1 ratio, and engine serial-number guidance made selecting the replacement unit straightforward. Confirming your water pickup style before ordering is key.
The product page clearly detailed the TorqueMaster housing design and gear ratio options for 200–300 HP V8 Pro XS outboards. The 20-inch shaft configuration was simple to identify, and the fitment assistance saved a lot of time compared to guessing.
The most important detail for this Mercury replacement lower unit was matching the 1.75:1 gear ratio and 20-inch drive shaft length. The page made it easy to cross-reference my engine year and serial number. I recommend checking your prop shaft and water inlets first.
The TorqueMaster-specific guidance ensured I received the exact lower unit for my 225 HP V8 Pro XS setup. Arrived safely packaged in a heavy-duty crate. Serial-number verification with customer support prior to shipment made installation hassle-free.
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