First, this achievement is not missable and there are infinite Abadon Mutant Crusher available in the open world.
This solution will explain you the random spawn locations for this achievement.
There are atleast 2 random spawn locations in the world for Abadon Mutant Crusher. The first location is in southeast of the town 'Gunbarrel' in a meteorite craters. The second random spawn location is in the southwest of the town 'Wellspring'.
I found (later) a third random spawn location. Directly above from the first MBTV location in Broken Tract (Picture)
If are the Abadon Mutant Crushers not in these locations fast travel back to the town(s) nearby and come back. The locations are shared with smaller bandit camp activities.
For 'The Bigger They Are' achievement just farm 6 of these crushers (You kill 1 during the story)
There are also 5 fixed locations (mostly in underground, one location in each world region except Broken Tract) with Abadon Mutant Crusher in the world. These locations can you also use for this achievement. These locations are marked on your map after you discovered it with a Mutant icon but honestly it is not necessary to use these locations for the achievement.
You can also get the "Crushed" achievement if you kill one crusher in these locations with the Phoenix (The Phoenix is your start vehicle)
The Crushed achievement in RAGE 2 worth 98 pointsKill an Abadon Mutant Crusher with the Phoenix