Is stock transmission cooler enough?

[Dave12]

My 99 Silverado NBS 2wd 1500 5.3 with the factory tow package has a external transmission cooler. Is it enough to keep things cool towing a 6500 pound 5th wheel through relatively flat terrain?

I have a Derale remote fan cooler that I asked the guy who is installing my 5th wheel hitch to install. He says I don't need it because I alreay have the factory cooler.

Thoughts? Is this not a more/cooler is better situation?

Thanks,

Dave

[GreaseDog]

none of your drivetrain is up to snuff for pulling a 5th wheel. the 10 bolt rear is an accident waiting to happen, the 60E is as well. both are known for failures especially when abused (and you cannot say that you're not abusing it with a 5th wheel trailer). the torque output on the 5.3 is better suited to a car than a truck. while we're at it, your hitch guy probably isnt worth a crap either. nobody in their right mind around here would install a 5er in a 1/2 ton truck.

[Dave12]

Okay....So obviously the stock tranny cooler isn't enough nor is the rest of the truck by the sounds of it.

Dave

[96ImpSS]

How often, or miles per year, do you intend to tow that 6500 lbs?
In flat terrain you can make it work. Take it relatively easy on the throttle on takeoffs, manually hold the gears longer as it's accelerating up to speed, manually downshift before upgrades to give the TCC a chance to re-lock before you really get into the throttle to make the hill, and your powertrain will last a long time.
I'd be most concerned about how stable a regular duty half ton suspension will be with that much load in an emergency situation.
If you must do it, forget the 2 second following rule, use the 10 second rule!

[Dave12]

Towing will not be very often. A couple of times per year. Likely 1000 miles at the most. Truck is having helper springs installed along with the hitch. I'm familiar with taking it easy. My previous truck was a 98 with a 6.5 and it required a delicate touch to keep the coolant temps and exhaust gas temps in check, same with braking. There were times when I just didn't have anymore brakes but still needed them. I managed to survive and drive even smarter because of it.

I know it's not the "best" vehicle for towing that trailer. If I lived in a different part of the world (mountains) or towed more frequently then I would have a 2500. This is my daily driver so I need/want something that is going to get me where I need to go on a daily basis without costing me a fortune in fuel and up keep.

I know there are modifications that have to be made to make it work better. I had to do the same with my 6.5. I've added the additional springs, I'm running Load Rated E light truck tires instead of passenger tires, I will be adding the additional tranny cooler, I will be getting my PCM tuned, if my tranny blows up I'll get it rebuilt stronger.

Thanks for the advise and being a little more optimistic.

Dave