Originally Posted by Hightower
Do you think the transom/engine bracket/hydraulics is subject to more forces sat on the back of a trailer going down a bumpy road or wave hopping in the high Sea's?
I would think on the road (perhaps not more forces, but different forces, I guess...)
Wave hopping, you have quite a bit of force pushing the lower unit in towards the hull; it is released when the prop comes out of the water, and reapplied when the LU reeneters the water.
On the trailer, the motor is free to move to the extent of free-play in the entire tilt mechanism and steering system. Unlike in the water, it is free to oscillate against whatever stops are there, in both directions. The force applied by the momentum is then transferred to the transom, then the hull.
Then, too, you have the boat designed to handle the on-water stresses. The trailering forces are incidental.
Note that I have no data to back any of this up; but most of the stuff I've broken (and quite a bit that others have broken) was during trailering.