Sequence worked for me in the past...
goto AC 3D window, save as OBJ, when dialogue appears,pick element-material option, model rotated (as maya defauly z axis is actually y, but you can change this in maya), dwg unit 12inches...
On the maya side, set preferences (settings, pref, units) to 12" or 1', y=up - unless you export from AC model rotated...then...
Import, select options filetype: OBJ, resolve clashing nodes w. filename, create multi-objects = false (I wish could be 'true'!).
Then be sure to set all your camera clipping planes (att manager in Outliner is how I do it) to 0.00001 near, 10,0000 far, so you can see the model(;), right click in any view window and 'select all' then hit 'F' for fit, and you will see where your model is, sometimes it's a million feet off maya's origin, I suggest saving your AC model with a datum/origin at some useful corner.
You can then insert the model's pivot (insert button on kybd, then ctrl'c snap the tumble pivot somewhere on your ac model, and centre it on maya's 0,0,0).
That has always worked for me in the past (w. version 8.0 to Maya 4.0). Only for some reason I just tried to export from 8.1, to Maya 4.5 and got an error reading file warning...hmmmmm is this the problem you are having I wonder, or did you get this far??
A.
Andy Thomson, M.Arch, OAA, MRAICDirector
Thomson Architecture, Inc.Instructor/Lecturer, Toronto Metropolitan University Faculty of Engineering & Architectural Science
AC26/iMacPro/MPB Silicon M2Pro