Have you ever replaced the cassette?
Did your trucker come with a Shimano Deore crank? If so, they last a lot longer than 8,000 miles.
My guess is, that a new crank is the wrong guess.
If you feel the need, 9 and 10 speed Shimano cranks are on sale for half off now that 11 speeds are out. I got an XTR 985 for $249.00 last summer. If you look around you can get a Xt crank for less than the velo Orange.

https://www.youtube.com/watch?v=dH-gnMSzmtI