This topic came up in another venue, and I figured it was worth a repeat here. One of the issues with many of the Menard's boxcars, certainly with the ones several years old that I got with the diecast trucks, is out of gauge wheelsets. All of mine are too narrow about about 50-60 thousands. It doesn't seem like much until you run them over some of my Ross switches! While I have minimal to no issues with almost any other brand of rolling stock, the Menard's boxcars have been problematic and cause frequent derailments. I was contemplating replacing all the trucks with MTH trucks, but that's kind of defeating the purpose of buying a $20 boxcar! 
As it turns out, it's possible to reguage the wheels in the trucks while on the boxcar! It's actually a very trivial process! After doing a couple carefully and measuring to make sure all went well, I developed an "eyeball" technique of doing them that knocked down the time to next to nothing!
Using the Frank Timko Wheel Puller, I just slide it around the wheel and finger tighten it against the outside of the truck until it's just firm. Then I give it about a 1/8 turn twist, that moves the wheel out on the axle about 50 thousands, just enough to correct the wheel gauge. Move onto the next wheel set until the car is done! Simple and quick! It turns out the wheels are not on the axles all that "firmly", I didn't need a wrench to do the job, just used my fingers on the knurled screw head. The only trick is to swivel the truck until you can center the wheel puller over the axle and then you can just apply a little pressure.
Any of them that still have the coupler issues will get MTH freight trucks and my fleet will be functional again.
