SOLUTION. Shuddering from 35-40 mph. Clunk into 3rd gear.

2012 Tacoma Prerunner 4.0 V6 Automatic transmission
~100k miles

Ok so I dealt with a clunk into 3rd gear and a really hard shudder at around 35-40 mph.
After trying all the carrier bearing drops and shims etc., I finally took it to Toyota. They told me I needed a new transmission and priced me $5,600 with labor included. They said they do not fix transmissions, they only replace them.

I took it to a guy I knew who has a transmission shop with a good reputation. He told me the torque converter broke (possibly from not having the right amount of transmission fluid from the factory) and a metal piece from the converter was eating away at my transmission. Cost me about $2400 for a rebuild.

I’m posting this just to help anyone that has a similar problem.

 

I had a similar problem with my torque converter just without the 3rd gear clunk.