There is a gentleman in my 4x4 club with a pristine FJ62 on 33's. He did about 4 trips with us which require going over the grapevine north of los angeles on the 5 fwy. He wrecked his transmission within 5 months of being in the club.
One way to make sure you're not wrecking your transmission is to make sure your torque converter is always locked up in 4th gear when pulling grades or for that matter, any long drive. If you are always stuck in 3rd or shifting up and down from 3-4 then you are heating up your transmission.
Question 1:
Do you know what it looks like on your tach when the torque converter locks up in 4th? If your answer isn't yes then that needs to change.
Question 2:
What temperature does your transmission peak at during a long drive? If you can't answer that then you cannot say your truck is ok on 33's with stock gears. Anything over 230°F for me is troublesome and different people will have different answers. My transmission normally runs at 190°F when not working hard.
One way to make sure you're not wrecking your transmission is to make sure your torque converter is always locked up in 4th gear when pulling grades or for that matter, any long drive. If you are always stuck in 3rd or shifting up and down from 3-4 then you are heating up your transmission.
Question 1:
Do you know what it looks like on your tach when the torque converter locks up in 4th? If your answer isn't yes then that needs to change.
Question 2:
What temperature does your transmission peak at during a long drive? If you can't answer that then you cannot say your truck is ok on 33's with stock gears. Anything over 230°F for me is troublesome and different people will have different answers. My transmission normally runs at 190°F when not working hard.