48RE Tow-Haul Mode

[PKearny]

I am probably missing previous info but can't seem to find the direct answer. With the 2004 48RE, does engaging Tow-Haul Mode simply inhibit 4th gear while preserving normal T/C lockup or does it also prevent T/C lockup in 3rd? Obviously, there may be conditions under which one may want to operate in 3rd with the T/C locked to mitigate transmission temp elevation. The specifications seem to dictate highway speeds in excess of what I am comfortable with to maintain O/D & T/C lockup under all conditions. I am hoping that I can inhibit 4th gear, recover RPM and maintain T/C lockup out of respect for transmission temp. Any and all info is greatly appreciated.

 

[XJSuperman]

You are correct. The converter will (and does) lock up in 3rd(drive) from about 49MPH+.

All the "tow/haul" mode does is lockout/inhibit overdrive (4th gear).