Do you have the body shell off?
The drive shafts go each direction from the motor into worm gears above each truck. The worm gear cover also acts as a retainer for the trucks. Be sure it is snapped snugly down over the gear housing. Check to make sure the pair of "ears" have not broken off that engage the frame that keeps the truck from dropping out.
Might be something else but this is one thing to look for. They are notorious for becoming dislodged on the boat ride from Asia.
If they are in place and the engine runs fine then, as Andrew points out, a little looseness is part of the design.
Good Luck, Ed
kh25 Hello I have an atlas classic ho scale gp7 that runs great but the trucks are a little loose all the wires are intact how do you fix this?
Hello I have an atlas classic ho scale gp7 that runs great but the trucks are a little loose all the wires are intact how do you fix this?
Are the trucks physically hanging by the wires or does the locomotive tilt to one side or the other?
What you are describing in itself is not a problem. My Atlas Classic GP7 trucks are also "a little loose" compaired to some other locomotives, but that isnt really a bad thing. You dont want them to be perfectly rigid, or otherwise the locomotive will not run over slightly uneven track. Please be much more specific.