Overheating during towing

My 01 tacoma 4x4 3.4 is overheating on every hill when i pull my 4000lb boat. It does great on flat but overheats immediatly on hills. Overdrive is off and ect/power is on. I know its a bit much to tow but it shouldnt be overheating.
any suggestions besides the obvious tranny cooler

 

maverick491 is definitely the guy to talk to. I would read this over before you go asking questions, if you haven't already. He goes over a tone in there.

http://www.tacomaworld.com/forum/towing/4031-tacoma-towing-bible.html

 

I'm getting Chris4x4 on this too-but our towing capacity for 2001 V6 is 5000lbs so it's not the weight-maybe your cooling ststem needs attention.

 

it just seems strange that its only on hills. its like the tranny heats up almost instantly and causes the truck to overheat.

 

fluid is at the right level and thermostat would cause spikes at other times other than just hills. Fan has resistance when turned off and clutch is not locked up. Coolant is green... I know i know it should be red. but do you think not running toyota coolant would do this?

 

Think of it this way... You're towing capacity is 5,000lbs. You're towing 4,000lbs.

When you're driving uphill, that 4,000lbs is a lot heavier and takes a lot more effort. You lose momentum and need the additional power to get it up the hill. That is not uncommon for vehicles being expected to tow close to their rated limits.

When was the last time you checked your radiator fluid? Do you have enough in it? Is your overflow tank at the full mark? What is your fluid rated to? Are your fans working? When was the last time you had a radiator flush?

We had a 99 Grand Cherokee that we towed 6500lbs with to Tellico a couple times. Rated capacity is 6500lbs. Guess what? Every hill, the temp gauge went into the red and every downhill, it went back down again. Typical....but not alarming.

 

I would advise leaving the 'ect switch' in off position because IMO it being on prevents the torque converter from locking out at 52MPH like it would in normal mode and may cause tranny to overspin unneccesarily

 

first time for boat pull. fluid is at correct level. And that a jeep thing! jk

 

Where wuold it be located Chris...cause on mine I see a small rectanular one right in front of the AC cooler-is that for oil?

 

i agree with the tranny cooler. i just thought it seemed like something else may be wrong. does toyota coolant make a difference?

 

Since the tranny did get hot, should i change the fluid now?

 

If memory serves me it's about 2''x6''