This is exactly why I added an after market cooler to mine, I pull a 5000 Lb boat from Jax to the Keys. 400 Mi. I eliminated the cooler in the radiator, made no sense to me....the radiator is a heat source of 190 + degrees. I kept the factory aux and ran the aftermarket in series with it.

 

You shouldn't have any trouble with tranny temps pulling 3200 lb. If you get up to 8000 lb to 10,000 lb, then you might have the temps go up if you are climbing hills. With a V-10, you probably don't even know that boat is back there.

I towed my pop-up camper about 230 miles round trip this past weekend. I think its max gross weight is 2200 lb, but I know it was lighter than that since we didn't have much of our gear in the camper. We are former tent campers, so we pack fairly lite - food, clothes, bikes, firewood - all in the back of the truck. I ran with the air conditioning on which is going to reduce the tranny cooler efficiency since the cooler is tight against the A/C condensor. On the interstate running 60 - 65 mph the temps ran between 165 F to 180 F. I ran with the O/D on where it was fairly level. The temperature didn't seem to change with O/D on or off. I got off the interstate and hit a several mile stretch of road where I hit about 10 redlights, everyone red of course [:@] so it was stop and go traffic. In this stretch, the oil temp hit 195F, but cooled down once I started moving. Outside air was in the low 70's.

On the way home, the temperature was in the low 90's. The oil temp never got above 180. About 2 miles before my house I had to go up a very steep hill. I had the truck nearly pegged, travelling about 25 - 30 mph. The temp jumped from 180 to 210 F going up the hill which is less than 1/2 mile in length. The temperature then starting coming down when I got past the steepest section. This just shows that unless you are really working the engine and you have an adequate cooler, you shouldn't have to worry about your oil temp. Now if you have a heavy trailer and you need quite a bit of throttle to maintain speed or are traveling up long, continuous grades, you might have some problems. But here in central PA we have rolling hills, so you get a little bit of heat build-up going up the hill, then cooling running down the other side.

alcedo - I've thought of bypassing my radiator also. It's just that in the winter up north here, I wasn't sure if it would be better to allow the radiator to warm up the fluid. I know the tranny won't go into overdrive if the oil temp is below 40 F or 50 F. I wonder if any else who lives in a cold climate has any experience with this.

 

It pulls my boat very good. I think the trailer i haul my atv's on (20' tandem with 4 big atv's) might be a little heavier but i pull both of them with od allways on[8D]

 

Shott,
I am trying to find these "fuse look-a-likes" so I can do some wiring because I want to wire into my fuse box instead of splicing into existing wires. Where have you seen that sort of thing? Auto parts stores?

Also, does anyone know if your average rocker switch that you can buy at auto parts places cause a lot of resistance? I need to add a toggle switch in a circuit, but I don't want it to cause resistance.

Thanks