do you always leave in 3 and tow/haul? I thought if you are using the tow/haul you can leave in regular drive and let the computer shift the way it needs vs keeping it out of OD also. thanks for the update - let us know what the temp looks like when driving normally on the highway for a while
and yes only 83...finally! the 105+ for weeks straight was getting old, it is about 90 up here in Dallas now

 

Yes I do tow in 3 and tow/haul enabled, it seems to be a lot less stressful on the tranny and keeps it from constantly having to shift out of OD every time I hit a small incline. It also seems to keep the trans fluid temp down when towing in 3.

Here a couple of points in the Onwers Manual on Tow/haul

"The Tow/Haul mode works with the Autoride®
feature, if the vehicle has this, to enhance the ride
when trailering or with a loaded vehicle."

"Your vehicle has a Tow/Haul mode. The selector
button is located on the end of the column
shift lever. You can use this feature to assist when
towing or hauling a heavy load or if there is a
need to charge a battery installed in a trailer."

"You can tow in DRIVE (D). You may want to
shift the transmission to THIRD (3) or, if
necessary, a lower gear selection if the
transmission shifts too often (e.g., under heavy
loads and/or hilly conditions)."

Tow/Haul Mode
Tow/Haul is a feature that assists when pulling a
heavy trailer or a large or heavy load. The
purpose of the Tow/Haul mode is to:
• Reduce the frequency and improve the
predictability of transmission shifts when
pulling a heavy trailer or a large or heavy load.
• Provide the same solid shift feel when pulling a
heavy trailer or a large or heavy load as when
the vehicle is unloaded.
• Improve control of vehicle speed while
requiring less throttle pedal activity when
pulling a heavy trailer or a large or heavy load.
• Increase the charging system voltage to assist
in recharging a battery installed in a trailer.

 

interesting, I have not towed much and the only vehicles I have used did not have tow/haul so we just put in 3 and went on.
what are you RPMs on the highway when going 60 mph in 3 and tow/haul?

 

If I recall it bumps the RPM's out about 300 to 500 rpm's
On our trip to Yellowstone in June, towing the trailer, I'd say my MPG dropped about 1-3 MPG towing in 3 depending on terrain... over all I think I got about 17mpg... I always did 5 to 10 mph below posted to keep from having to pass folks and not play the leap frog game on long stretches...

 

Any chance you have the part number for the kit? I can't seem to find it on GM Parts Direct.

 

Its listed under the "accessories" tab
part number for the 5.3 2007 is 19171483

19171483 Transmission Cooler Recommended for Trailer Towing Upgrade w/ 4 Speed Automatic Transmission (w/ RPO Code M30, M70, w/o RPO Code Y91)

 

I've got an 09 burb with the 6-spd auto, gmpartsdirect shows the same kit #19171483 but description is for the 4-spd. Does anybody know if this kit will fit the 09 Suburban?

Gary

 

Your parts man can look it up and tell you. Or you can try gmpartsdirect.com.

 

Nice write up.

 

Welcome to the forum Tony_V.