Hard Shifting

Hey all,
First let me start by saying I'm not a mechanic but I am an electrician so I do know my way around tools in general if that is applicable. I have a 05' Prerunner V6 Auto that is shifting hard from start and lurching when shifting from park into drive and sometimes when I break. After doing some research I saw various fixes for this.

1. Grease the splines/U joints,
2. Get an AAL or helper leaf,
3. Have the Transmission TSB done.

Since I'm new to this not much of what I found makes much sense to me but I inferred the answers with a little digging. Am I on the right track and has anyone experienced anything like this so I may learn from it? Also if any of the above fixes would work could someone explain them with some more explanation? Thanks for the help if anyone can offer any...

P.S. I noticed my girlfriend had it in 4th when she picked me up the other day after driving on the freeway for about 70 miles. She said she didn’t realize and was driving at 75+ for awhile that way. Could that somehow be a cause to my problems? I got it used recently so I’m not 100% sure of its drive characteristics.

 

Nothing?...should I post in the 2nd gen general forum instead?

 

Well I setup an appointment with the stealership to check on any TSBs I may have...the main one being the transmission TSB. Since I got my Taco used it is out of factory warranty and I'm not sure if the TSB is covered or not but I guess we will see. Failing that or if they want to rob me just to reflash my ECM then I'll try to look at what I can do with my driveshaft. Thanks for the encouragement though. If anyone else has any advice I would appreciate it!