Yesterday, I was running my Lionel #18295 TMCC equipped SD80MAC and noted a thumping sound as it cruised around the layout. I inspected the traction tires after the run and noted the original tires were looking hard and tired as they were around 15 years old. I decided to replace them; after disassembling Lionel's worst truck design ever ( a total PITA likely designed by someone who hates mechanical things....) I got the traction tired axle out (can't replace them installed as the side frames screw in from atop the truck - see previous parenthetical remark). I went to remove the tire and found it was almost "glued" into the tire groove in four equally space points. I eventually got them off only to find that they were 'attached" by four "sprues" of traction tire material that were in what looks like four laser-drilled holes from the flange edge through the back of the flange/wheel web. I managed to remove the "sprues" by pushing from the flange through the wheel back face. I can only surmise that somehow the traction tire material must "ooze" into these holes as the replacement Lionel tires do not have any of the sprues attached to them and there appears no way you could actually install one this way as the holes are very non-dimensional on the flange-groove intercept.
To make matters worse, the supplied replacement tires have a varying material thickness around the circumference of the tires which still leads to more "thumping" while running as the flange-less innermost axle is pounded down onto the rail-head by the "oblong" traction tire. I presently have some MTH (DE18) tires installed, but they are not quite thick enough to reach the railhead from the tire groove on one wheel..... Lionel lists the tire as 0.034" thick which is pretty substantial when you actually view it in-hand.
This is the only Lionel diesel I have found this set-up on to date. Your results may vary.
Pictures attached.
What a giant PITA that one is, I can't imagine what possessed the engineer that did that one!