Ok guys. I finally got a chance to do some towing with my new Dodge (99' 2500, 5.9 gas, 60's all around, 4.10's, auto),and I now have a few questions. Trailer is a 20' backhoe trailer, load was a 77' F250 Highboy. When pulling the empty trailer at around 70-75 mph on the interstate, I noticed the tranny kicked out of OD twice when I encountered a hill. But with the trailer loaded and running on rural highway with many curves and hills at only 55-60 mph, the tranny never ****ed once. I expected it to try and downshift all the time( that's why I took this route home, just to see what it would do), but it never even thoght about it. Now I think I wannt to load it up again and run the interstate to see what happens. I suspect it is more of a speed issue more than anything else. I am guessing that if the tranny wants to stay in overdrive and not shift in and out then it shouldn't be an issue. Please let me know if my thinking is correct/incorrect. Thanks for any replies.

 

you should not be towing in OD... the OD unit sucks already and putting a heavy load like that on it will only accelerate it's failure.

I would go get an aftermarket tranny cooler with a fan on it. they have a built in switch to turn on at 160 deg and that'll help extend the life of any tranny. And, you should probably put a shift kit in there too.

 

Most definately, DO NOT TOW IN OD. Simply, that is why they have the lockout button. I drove Tow Truck for 7 years and even our A/T equipped Furds had the lockout feature. We took it a step further and made it a habit to lockout the OD for all driving except unloaded on the Interstate.

 

dont do that man or say good bye to your tranny!!!!! get a aftermarket or have someone make it stronger

 

So am I most concerned with heat buildup(of course a bad thing), or is it a mechanical weakness inherent in the overdrive of these transmissions that is the problem? I've read about the pans with fans and temp gauges and it sounds like a great upgrade.

 

Well many people argue about this and have disagreements. I don't pull anything heavy personally but my dad has had autos and pulled many loads. I know the trannys are prone to problems but as long as it is staying in overdrive and not going in and out a lot and getting the tranny hot, there shouldn't be a problem towing in OD. We've had two V-10 autos, yes I know they are 3/4 tons (and still have one of them in the family) and pulled numerous heavy loads with them and I'm talking #10,000 plus easily. Never worried about kicking the OD off at all. The one my brother currently has, has about 60,000 miles and the one my dad traded back in 01 had over 70,000 on it and didn't have any problems. Oh ya, they both have 3.55 gears in them. So as for towing in OD, if it doesn't kick in and out, there shouldn't be a problem. When it comes to pulling and dealing with gas-burners V-10s do kick ***.

 

It's a design flaw in the transmission case that is the leading cause of failure. It was fixed in the 3rd gen HD trucks.

Aux Cooler (which your truck probably already has), an actual temp. gauge, deep transmission pan, synthetic fluids, and towing heavy loads with OD off are some things you can do to keep the transmission healthy.