Hey all,

Used to tow with an Armada, and there was a TOW button I just had to flip on... with the 4Runner, theres no such thing so...

I've been searching around the forums and noticed some comments on towing in 4S all the time and not in D. So I wanted to throw this out there...

I'm towing a 6x12 Cargo Trailer, about 8.5' high. With trailer and contents i'm usually around 3700lbs. 90% is highway and there are a lot of large hills i'm going up and down on that trip.

I've always towed in 2wd and in D without issue... on level ground i'm usually around 70mph... going down a hill about 80mph to pickup some easy speed before going back up a hill which i let her slowly drop to about 55mpg to chug up the hills.

I just read that towing in D (overdrive) puts way to much stress on the drivetrain. And to ALWAYS drive is 4S. But at those speeds, wont that just pull the RPMs way to high?

I just got the Torque app going and see the tranny temp hit 230f on up-hill pulls but it doesnt go higher then that. Thats why I went searching to see what the average temp is for a tow.

FYI I just installed a P3 Brake Controller, have not used it yet so we'll see she feels now on braking.

Thanks for the feedback!

Ok my .02
Not sure what the TOW button did on the Armada, but I'd bet lunch that it locked out the overdrive and put the trans in the 1:1 cog. That would be 4 in the 4runner.
Towing or not, a constantly "busy" transmission will push torque converter and trans pan temps well beyond what most folks would guess.

Case in point: About a month ago my wife and I went to go to dinner and found the easy way to our favorite haunt (about 22 miles away) blocked and backed up most of a mile. We quickly exited and got on a curvy back road that would drop us reasonably close to the restaurant.

I left the 4Runner in D and happily ran the curvy and up and down hills road and let the truck manage the shifting.
However, when we arrived and I glanced at the Scan Gauge, I was horrified to note that the converter temp was 211* pan temp was at 203*
Outside temp in the high 80's average speed 50ish.

On the way home we took the same road, BUT i put the trans in 4. This time I payed attention to the SG and never saw the converter temp over 186* and the pan at 183*.
The only difference...about 1000 down and up shifts on the way over and seemingly about 1/10th that on the way home.

Anecdotal? yes. But it shows what towing in a "proper" gear ratio can do for a transmission.
Remember, the 4Runner has a 3.73:1 axle ratio...in 4th =1:1
Multiply that 3.73 by the 4Runner's 5 gear ratio (.71) 3.73 x .71=2.65:1
Toyota did that for mileage, not towing. With a 2.65:1 "mileage ratio" any wonder the 4Runner down shifts at the slightest provocation?

Bottom line...DONT tow in "D" and get a trans cooler if you plan on towing often.
Good Luck
AMLOR

o

100% agree with “AMLOR”, as I also tow and have scan gauge and can confirm same findings regarding transmission \TQ temperature vs. D\4 gear selections.