I need to change the speedometer gear since it's reading 3mph slow due to larger tires.

Besides getting the housing clocked in the correct position is there anything else I need to know to reinstall it?

Such as is there a trick to get the gears to mesh or do they do it automatically?

 

It's pretty straight forward. Sounds like you are already aware of the most frequent issue, and if you put it in the correct orientation like you indicated, it should mesh up just fine. Literally a 5 minute job.

 

Be ready just in case ATF feels like pouring out. Make sure range of your gear is lined up with the BOTTOM of the bracket ( roughly 6 o'clock) that holds the gear in. I messed up a gear by assuming the numbers were centered on the bracket.