If you don't do this and you press down on the car as these trucks have spring action, the sides might go flying or it may never happen. Anyway I would recommend this for the Atlas trucks
I'm not trying to prove anybody wrong just trying to help out the team.
Gary is correct and the trucks done his way, which is the way I do it, have better rolling characteristics. I quit using Pete's method when I noticed the trucks didn't roll as well as they did before the conversion. That isn't to say that they wouldn't roll.
Concerning the Lionel truck "secret sic.", the problem occures when Kadee #805 couplers & boxes are used, because all that clap-trap steel stuff on the Lionel truck interferes with the rear of the Kadee box, when the truck rotates. When the "short box" Kadee couplers (#806 I think) are used, you do NOT have to cut all that crap off the Lionel truck.
Since I have long been using the Kadee #805 couplers (I purchase them in bulk), I have also had to use the Dremel to cut all that crap off the few Lionel cars/trucks I have up-graded, just as Laidoffsick has shown, above.
I agree with Hot Water. I used 806's without cutting the Lionel truck. After seeing Laidoffsick's method, I tried it, and was then able to use Kadee 805/740 couplers which have better action than the 806/743 couplers.
