To the latch inside the upper unit while putting the drive onto the gimbal assembly by yourself? The ITS shaft is so long that as I struggle to gently guide that in place, the latch, which I already pulled forward, seems to get pushed back very easily by the fully extended cable as I slide the drive on.

Thought someone may have a method to prevent this.

I've done my ITS a few times, do not recall any trouble, get it resting on the studs with 3/4" of daylight, move the shift lever where you want it and or use needlenose, goes ka-chunk and it's in.

It's suppose to do that. When you put the drive it shifts to neutral. Thats how you know it's on properly.

yea, mine isn't going on that nice. The shaft slides in perfectly but something isn't happening on the clutch. I just can't see the cable and put the drive on at the same. I guess I need to get another set of hands.