How do I know if I need a counter-rotation gearcase?

Only twin-engine boats use one. On a twin rig the port engine usually turns counter-clockwise so the pair cancels out steering torque. A counter-rotation lower unit is not interchangeable with a standard one, so check the engine it came off before ordering.

What shaft length do I need?

Measure the transom height from the top of the transom straight down to the bottom of the hull. Roughly 20 inches is a long shaft and 25 inches is an extra-long shaft. The gearcase has to match the engine it bolts to, not just the boat.

What does a remanufactured gearcase include?

The unit is disassembled, inspected and rebuilt with new wear parts to factory specification. OBR builds its Bombardier reman gearcases in the USA. A refundable core deposit applies, credited back when you send the old unit back in rebuildable condition.

Evinrude · Johnson · OMC · Sea Drive

Lower units, rebuilt in the USA.

OBR Parts & Marine remanufactures Bombardier gearcases with new wear parts and factory specs, while stocking new units where they still exist. Below is an optimal fit guide: horsepower, years, and the rotation and ratio details that decide whether a lower unit is the right fit or goes back in the box.

Built in the USA Reman & new Core credit back Shipped nationwide

Remanufactured OMC outboard gearcase, lower unit

What fits what

Every OMC, Johnson and Evinrude lower unit OBR carries, by horsepower. Click a row to open it in the live catalog with current availability and pricing.

Gearcase fitment · OMC / Johnson / Evinrude · reman unless marked new
Horsepower	Years	Unit	Type
40 / 50 / 60	2004 →	E-TEC, 20″ shaft	Reman	View →
50 / 60 / 70	1989–2001	20″ shaft	Reman	View →
75 / 115	1995–2019	60-degree block, 2:1 ratio	Reman	View →
88 / 140	1992–1998	Standard rotation	Reman	View →
90 / 115 / 120–140	1995–2019	Big Foot	New	View →
150–250	2000–2007	Magnum	Reman	View →
150–250	2008–2019	Mag II	Reman	View →
150–250	1979–2019	Counter rotation (port side of a twin)	Reman	View →
150–250 / 3.0	1979–2019	Sea Drive	Reman New	View →

See every OMC gearcase in the catalog →

Three things to check before you order

Rotation

Single-engine boats run standard rotation. On a twin rig the port engine usually runs counter rotation so the pair cancels out steering torque.

The two are not interchangeable. Check the engine it came off, not the boat.

Shaft length

Measure from the top of the transom straight down to the bottom of the hull. About 20″ is a long shaft; 25″ is extra-long.

The gearcase has to match the engine it bolts to, so read the model tag too.

Your core

Reman units carry a refundable core deposit, credited back when you send your old unit back in rebuildable condition.

How core deposits work →

Technician rebuilding an outboard assembly at the OBR bench

Diagnosis

Is it really the lower unit?

1
Milky or grey gear oil
Water is past the seals. Continuing to run it will damage your bearings and gears.
2
Metal on the drain plug magnet
Fine fuzz is normal wear. Chips or curls mean a gear or bearing is coming apart.
3
A whine that changes with load
Usually the result of worn gears or a failing bearing, rather than anything up top.
4
Will not shift, or jumps out of gear
Could be linkage or the shift cable. Rule those out before you pull the unit.

Send us the model number and we will quote it →

Shops order it wholesale

OBR has supplied marine dealers and repair shops since 1982. Becoming a dealer gets you wholesale pricing, live availability, and access to online ordering.

Become a dealer → Warranty → 251.645.2050