Tail shaft housing

I am going to be replacing my tail shaft bushing. I have been told by many that I need to remove my hole tranny from the car in order to remove my tail shaft housing on my A833 4 spd.

I had a 3 spd laying around the shop, so I took out the speedo gear, and then unbolted the tail shaft housing bolts, and the housing slid off with no problem.

It sure looks the same as my 4 spd, so wouldn't the removal be the same? I have had some people tell me that I need to remove the side cover on the tranny and undo some clips befor the tail shaft housing will come off my 4 spd. I just don't understand why it would be different than the 3 spd.

The only thing that should be different is in the tranny itself...not the tail shaft housing. Right?

Thanks

Phil