2005 supercab 2WD, 145 WB, 5.4, 4R75E, 3.73 LS diff., factory tow package.

I tow a 3500lb RV at 'brisk' rates and have never had any indication of a problem. I leave the tranny in OD and have not suffered any 'hunting' between gears.

I'm now retired so plan to do more trailering, including beyond TX/OK so hopefully I'll get into some real mountains.

Just curious .... how can I know when the torque converter is 'locked' for coolest running on my 4R75E?

I'm reasonably sure the 'locked/unlocked' status is reported to the ECU, will a Scangauge II report the converter status?
___________
BTW, the late model OEM tow mirrors that I learned about on this forum have been great.

 

I assume you have a tachometer. You can easily tell if it the TC is locked when in OD by how the tach shows the revs. If you give it gas and the tach only goes up with the increase in speed, then it is locked. If you give it gas and the tach goes up and down with the gas pedal, it is unlocked.
Normally at steady highway speeds it will be locked. It will only unlock if you give it gas. That or while going uphill.

 

If you plan to tow a lot, get a Scangage to tell you the trans temp. Best $150 you'll spend to save fuel and reduce wear and tear on your truck.

 

Obviously the SGII doesn't do anything but provide information. What transmission related data does it report other than temp?

 

Take a Look at the Xguage list, under Ford CAN.

 

Thanks APT - I'd just found that when you replied - that's the thread/forum I need to focus on for this topic.

Thanks again!

https://www.f150online.com/forums/ch...ii-xgauge.html