TQM1 Question

[salesdeity]

I have a 2016 25" 250 PRO XS model# 1250P83BD serial# 2B231534 with a RH TQM1 gearcase. Due to prop torque, my boat has a hard lean to port (the same side my 250lbs. sits) while on plane which requires me to drop the port tab scrubbing speed. I have moved both batteries, oil tank, and anything else that weighs anything to the starboard side. Boat sits level at idle. I want to try a LH gearcase and have found a NOS one for sale which was bought for an older (pre-2013 ish) 300XS. Will a 1689-842004T27 work? I believe the gearcase will bolt up but are the driveshaft splines the same so it's 100% plug and play? TY!!

[JOE54]

same splines

[salesdeity]

TY!!

[lpugh]

trim position has a huge effect on this
V bottem boat?

[EuropeanAM]

LH gearcase should not be used on SINGLE engine boats.

Your engine did not come with a Gen-1 TM gearcase. It very likely has a 25" Verado-Style SERVICE Gearcase.

That gearcase uses a standard Flo-Torq Hub, and does NOT have the cast-in Torque-Tab on the starboard side of the skeg (which helps to cancel out the right-hand torque for single-engine applications).

Let's get a picture of your gearcase from the rear (prop end) without the prop, as well as one view from the side that shows the ENTIRE gearcase and skeg (including mounting nuts and leading edge of gearcase).

[salesdeity]

Don, you are correct this engine came originally with the Verado style black 1" gearcase. The reason why this unit is on the boat is that I snapped the 1" propshaft at the friction weld when just a year old in 2017. Merc accepted fault and replaced under warranty allowing me to pay extra to upgrade to the TM1 8M0072953 you see in the pics. It does have the 1.5" shaft with the cambered skeg so it appears to be a TM1. Questions: 1)Why should a LH gearcase not be used in a single boat? 2) Will the 1689-842004T27 (label from box shown) bolt up to my engine? TY!
20250502_175616.jpg20250502_175453.jpg20250502_175651.jpg9a25f127-5130-45d6-901d-26298f55b02e.jpg

[EuropeanAM]

LH gearcases usually lack the cambered skeg and hydrodynamics that help to cancel out prop torque.

Normally intended to be in an engine combination that has at least (1) RH Gearcase, so that they cancel each other’s torque.