I'm a conservative driver. I've been using engine braking as well as my brake assist coming into stops. Always in 4th or lower while towing. I monitor coolant temps as I drive with BlueDriver but thinking I should get something more comprehensive. Coolant temps were fine pulling up passes in CO and through TX in summer traffic.
Truck is lifted with front bumper, roof rack, rear drawers, stock size tires but more aggressive tread. I agree, 4500 is easily doable.
Yep, I'm in a very hilly area.
Last year, I actually thought it could have been solenoids, but at the time my other truck was in another shop and I was looking at renting a car while this happened. I was also reading here about mixed results from folks who started out fixing a solenoid issue and then having other issues pop up, leading to transmission replacement after trying to avoid it. I was also fretting about the calendar, since I was about to be on the road all summer towing with it. So, bit the bullet thinking I would get another 200k out of it.
Nope, Toyota had no idea what went wrong. The tech had no info. And the service advisor told me I was probably pushing the truck towing the weight I was. That should tell you all you need to know about how knowledgeable they are.