But what wasn't all that shocking was the weakness in engines. That's because Alcoa ( AA), which makes the aluminum for it, told you to expect truck weakness going in, and Caterpillar did the same. Cummins came in at a high despite Alcoa and Caterpillar's forecast -- and maybe that was the real oddity. In fact, I felt bad for Caterpillar after I read the Cummins call because sales were pretty much consistent everywhere in this downturn. Still, what explains the strength in the others relative to Cummins? I think that unlike Cummins, which was circumspect about the future, Eaton told you that things had started to get better by the end of the quarter and that October has been good. Cummins gave you no hope to speak of. But, due to Eaton's comments, I am more emboldened to suggest buying Cummins after all of the estimates come down Wednesday. If there is anything that's truly disappointing about Cummins that's not transient, it's how little attention the company paid to its natural-gas-engine initiative. The company didn't even bring it up. An analyst asked about it, and the management's reaction was curious, to say the least. Mark Smith, the investor-relations executive on the call, responded to a query about how well its new natural gas engines were selling by saying the "acceptance has been good." Then, after a brief moment, he added, "In fact, our sales are running a bit higher than our internal projections." If that's the case, I would have thought that Cummins would have stressed it much more, yet it was more of an afterthought. It's totally depressing for those of us who want to see a switch from dirty imported diesel to much cleaner liquefied natural gas, especially with the new Cummins engine, which I thought was a very big deal for the industry. Look, Cummins is a great American company. It is going to do amazing things when fleets start replacing old engines and countries expand environmental laws to make for cleaner, less-polluting machines. Right now, though, I think Cummins has opened our eyes to the fact that this best-of-breed player is no more immune than are many others in the sector. To that I say: OK, if that's the case, the expectations are now wrenched out, and it's time to try to figure out a good entry point if, alas, it isn't here already. Cummins shares never sold off in light of all of the weakness abounding away. If Eaton is right and trucking is troughing, Cummins is the one to own. I bet it, too, is troughing, right here, right now, and you just caught still one more chance to pick some up at better prices than you might get just a few weeks from now. At the time of publication, Action Alerts PLUS, which Cramer co-manages as a charitable trust, was long JOY and ETN. Editor's Note: This article was originally published at 7:44 a.m. EDT on Real Money on Oct. 30.