Transmission 4-5 issue

My first vehicle a 2006 Tacoma 4x4,
I fixed it up from a salvage title but it didn’t have any engine or transmission issues. Now I have driven it for about 5,000kms. Yesterday I did some mild drifting on a frozen lake. Then when I got back on the highway the transmission was messing up it’s 4th to 5th shift. It was a different feeling than a transmission slip though.

The transmission completely disengaged going into 5th, the engine reved up to about 5k rpm and then it grabbed 5th.

When I tried to do it purposefully being super gentle on the throttle the same thing happened but it only reved to 3k rpm and then grabbed 5th.
It happens when the transmission is cold -16 Celsius or hot after driving for an hour.

 

Here's some reading. Not saying any of this will help but it's worth a try and will save you some money if you can DIY.

I'd start by checking the trans fluid level. The first two links will have the procedure in them.

The bottom link will have the maintenance items for 2nd gen. It also contains the other two links.

It could be the shudder issue common to the transmission. The product called Lubegard Instant Shudder Fix 19610 will help if that is your issue.

https://www.tacomaworld.com/threads/diy-full-flush-for-automatic-transmission.68462/

https://www.tacomaworld.com/threads/how-to-drain-refill-automatic-transmission.63851/

https://www.tacomaworld.com/threads/2nd-gen-diy-maintenance-quick-reference-guide.438945/