I've never had this problem with the Z, but good thing someone brought it up.
Another one of those, it doesn't happen much, but at least once a year on average.
With the Wb it's not such a big deal, the float decks are too heavy for me thou.
Of course, you know it, they almost never break when they're on the trailer
One trick that tends to work is if the lawn is 'curbed' at the street...
Is to back the trailer up at a 90-degree angle to the curb (likely you'll have to jackknife the truck so you don't block the
entire street), then letting the gate down on top of the curb straightens up that nasty angle considerably.
Also if it's on a hill, point the truck down hill with the trailer's rear pointing up, then gravity helps some.
But you still need at the least, a come along and some chain.
Some folks have mentioned installing a 12v winch permanently on a Z, the only thing that's stopped me
is the price a little, but mostly the labor, just thinking of drilling through that thick steel makes me tired.
Here's what I've done. Put your mower in neutral (dump valves). Un-hitch your trailer. Block the trailer tires. Run a tow strap from your truck, over your trailer and hook it to your ZTR. Drive truck slowly & mower will creep up your ramp.
That is awesome!
I'll have to remember this.