The issue I'm having is with meshes that have simple translate/rotate/scale animations. No joints or morph targets. The timeline is 5950 frames, so it's somewhat long. The animated objects seem to wander off their axis later in the timeline. At the beginning of the timeline, they behave the same way as they do in Maya, but if you scrub through quickly you can see them drifting all over the place. I centered the default view on a radar dish which is a good example of this behavior. It starts spinning on top of its post, but moves outward in a spiral path. It has no translate or scale keys, only rotation on the Y axis. All animated objects wander, including ones that do not rotate. Some of the turrets are especially bad: they seem to translate up and down in an oscillating manner along the y axis while steadily drifting off on the z axis. They only have one rotate channel keyed.
I initially exported an fbx from Maya with keyframes that cycle with offset. Next I tried baking the animation, in case there was some small offset error cumulatively adding up. No change in the problem. I went back to Maya and deleted keys from all redundant channels, e.g. all translate channels on objects that only rotate. No effect. I thought the scene might be too small and coordinates might be drifting due to rounding errors, so I increased the scale 20x and re-exported. Still no effect. I can import the same fbx into various software suites and this glitch doesn't happen, so I don't think it's a problem with the export. I've also tried binary, ascii, and various older versions of the fbx format. I'm considering making this a skeletal animation, but that wouldn't be ideal so I figured I'd ask first.
Thanks for you time, community! Sorry about the wall of text.