2nd gen towing

Hey guys wondering if anyone has had the same issuse. Recently took a 3+ hour trip while hauling my 2 4 wheelers.(03 grizzly 660 ,2010 grizzly 700... call it 2k lbs) My 2012 sbdc 4.0 4x4 auto had one hell of a time on any sort of incline on the highway. Was first time i had them on the highway, around town it does just fine but highway it couldnt get out of its own way. Sluggish would be an understatement.... could never find the right gear. Flat ground was fine but any incline was down shifting to 3rd or even 2nd at highway speed. Any thoughts on what to do?

 

I always have to manually select the gears when towing. It's always at 4 at the very most, even on highway. I just find that in od it gear hunts way more than it should

 

That's pretty normal. It will shift down to 2nd or 3rd and rev out to 5k rpms to get up hills.

 

These trucks are notorious for that. Be sure to get some kind of scanner or a cheap Bluetooth adapter and Torque Pro on your phone to watch trans Temps. You have to input a custom equation to talk to the trans temp sensor. Trans overheat light won't come on until 300° but fluid will start to break down above 220, which I guarantee you're hitting if your truck is anything like mine.

Best solution is to get a bigger truck. What I did in the meantime is add a larger external trans cooler. I did the

$185 Derale 52506 25 Row Core Stacked Plate Cooler Kit , Black

Derale 52506. A bit of custom fitting and have to move the horns but it was all bolt in. This will help disperse heat to a reasonable temp. The heat originates when the torque converter unlocks such as when your truck is downshifting and revving out to try to pull that load. Temps inside the torque converter can quickly reach 300° on longer runs like that. So in a nutshell the solution is to put in a big ass trans cooler, monitor your trans Temps (both the pan and torque converter), and you may still need to slow down and allow the truck to have its limits if you want your drive train to last.

The only way to get more torque would be regearing and/or supercharging, but for the price you pay it might not be worth it. For me it's the fact that I'll still get crappy mileage and still struggle to some degree even after dumping that 7k into the truck. So the real solution is a V8 or diesel with more torque.

My two cents.

 

Sounds like you had cruise control on - if so do not use towing as constantly downshifting.
As others said 2nd gen use 4th (no overdrive 5th) and in really hilly areas you will have to slow down and use a lower gear - no problem.
I assume it has the tow package and coolant is good.

 

The ATV's are going to be 1200-1500 lbs. Depending on the weight of the trailer you were over 2000 lbs and maybe closer to 3000. I used to have a Honda Rancher and Foreman that I pulled together on a 1000 lb trailer. That was almost 2500 lbs. I live in GA and have taken them as far north as Kokomo and as far south as Miami. Sold both and now have a 1200 lb Honda Pioneer 700 which is about the same weight as the others combined. My Tacoma pulls/pulled them fine.

I see you list a lift under modifications. I assume you also have oversize tires. That effectively changes your axle ratio and reduces the trucks power.

Where you tow matters, and you don't say. Most of my driving is at under 1000' sea level, never more than about 3000-4000'. When you are at higher altitudes there is less oxygen in the air and that also robs engine power. About 3% for every 1000'. If you live in a mountain state where 5000'-7000' is the norm and have mountain passes of 10,000' or more that is going to make a significant difference in power.

Never use Overdrive, place the transmission in 4th gear with that much weight. It is perfectly normal for it to drop down to 3rd gear on most inclines. And on really steep inclines 2nd gear might be needed too. I find it best to anticipate when I'm going to need a lower gear and manually downshift the truck BEFORE the engine starts to strain and I lose momentum.

What do you call highway speed? When pulling a trailer 60-65 is about as fast as you need to go. Expecting it to pull a trailer any faster and not struggle is unrealistic.

Using premium fuel when towing makes a difference, you'll find the need to downshift much less often. In fact, I started using 93 octane in all of my vehicles all the time. I can tell a difference in power even unloaded, but when towing it is especially helpful. And since I tow something fairly often, I find it best to just keep premium fuel in them all the time. My trucks are getting about 1 mpg better fuel mileage with it too. That doesn't completely offset the extra 50 cents/gallon for the fuel, but it does ease the pain some. For me the extra performance is worth the cost.

 

I'm going to blame the transmission...

automatics don't see the hill coming and prepare for it ahead of time. your tranny is reactive not proactive. sounds normal