I just bought an A & B set of Intermountain’s F3’s and the grills on both units was attached so poorly that there are 1/8" bubbles in the grill. It doesn’t lay flat against the carbody, but the ends solidly attached so the middle of the grill has several bubbles in it.
I’m not planning on returning it, as it was a mail order item and it’s an easy fix, but I had come to expect better quality from Intermountian…
Your model sounds like an exception to the rule, but both Athearn and Intermountain warns that the grills will expand differently than the plastic shells and they might look out of shape sometimes.
I was thinking since you just received these models, they may have been exposed to extrememy cold duging their trasit to you and migh just settle out on their own after a week or so.
If they do not correct themselves, lifting one end of the grill and reattaching that portion will solve the problem. I have noticed my Intermountain units need to be in the house for some time to correct their expansion problem.
For IM’s sake, you should contact them and let them know of the problem. (A picture would be helpful, too.) IM needs to know so that this doesn’t happen again. You might be surprised. They may even send you a new replacement shell so you don’t have to mess with it. Even if they don’t, you should let them know anyhow.
I had the same problem with sparate expanded metal grills glued to other plastic bodies - such as Athearn, Stewart, and Riarossi. Metal expands differently.