Does anyone tow with their truck/car in overdrive?
I was thinking that my V8 4runner would do ok in OD towing a double stack (total weight 1200-1300 maybe) but it didn't like it. Maybe even got a little smelly, if ya know what I mean.
Just curious. everything went fine when OD was off. I use this same truck to tow my 31. If I left it in OD towing that I think the truck would catch on fire!

I know what OD is- an extra gear... but why do auto trans tend to overheat when trying to tow with it?

Go over to RV.net forums and do a search or ask, you will find tons of towing info.
I used to tow in OD but I don't think you are supposed to.

Go over to RV.net forums and do a search or ask, you will find tons of towing info there.
I used to tow in OD but I don't think you are supposed to.

I towed in OD on my VX all the time. I had an auxillary transmission fluid cooler mounted on my radiator.

Didn't have a problem.

Aux cooler will help for sure - I have one on my truck and added one to the family van. You will, however, void your warranty if you tow in OD. Ask Charlie Harp, who got to stay in Key Largo a couple of extra days waiting on a new tranny one year.

my truck does have a transmission fluid cooler, part of the towing package, etc. I have been thinking about adding a fluid temp sensor.

Why do transmissions overheat when you try to tow in OD?

Pressure is reduced in the transmission in the higher gears. Once all the hard work of starting all the weight from a stop is done (first and second gear) the pressure kicks back. Once at highway speed, the ability to turn the transmission faster than the engine (OD) is easier. Start heading up an incline and the transmission realizes your hiding some lead here somewhere (25 to ??% more load) and it was "suprised". Typically, an incline is an easy task. Now you've got the tranny huffing and puffing and the heart is not pumping enough blood. Think of smoking your favorite cigar while on a treadmill.

Some vehicles do better than others, it's taxing on all of them to some degree. Changing the fluid more often than recommended is a great insurance policy.

Heat is certainly a tranny killer, but the problem is slippage.

An automatic tranny has the ability to slip when it is overloaded. When you pile on the pounds or windage, you must run in a lower gear to prevent slippage. There is a clutch pack and also the torque converter is a fluid driven device. When the loads get high, the tranny slips more and the heat builds up.

Even a cooler really doesn't solve the slippage issue much. It just keeps the heat down some.

Heat is a sign that you have slippage.

The cure is to gear down.

ditto

OH, all of you must have an AUTO tranny!

My V8 Dakota Quad Cab, pulls in 4th, or 5th. Gets about the same MPG in 4th or 5th until about 75 mph+, then it's 5th gear.

I recall reading the manual that came with my vehicle and it stated not to tow in OD

Right...a staight drive will also cure your overheating issues!

Just don't lug it in 5th when 4th puts you in a better rev range.

You don't save much gas (if any) by running in OD with a load, however, you just might F...Up your ride!

The warranty disclaimer might be a clue.....

b/c of the load, most "normal" sized vehicles with an auto trans won't be able to lock the torque converter in OD. The TQ produces a lot of heat when unlocked. Coolers are not expensive to buy and if you put it in yourself you can probably be done with ~$50.

Now, my F350 diesel tows just about anything in OD, but... i do have 600+ ft-lbs of torque and an aux cooler

Hey Jack - I'm a tremendous fan of manual transmissions. Not offered in my 1995 Mits Montero unless you go to Mexico or Puerto Rico. That always bugged me - standard locking rear diff but no optional stick??

Will - I tow all the time in OD with my V6. Pulled nine Waves on the 14-hour drive to Rick's one year. Warranty isn't an issue on my truck anymore, though. I'd bet that your manual says the same thing mine does - towing in OD voids all warranties. Only an issue if A) you're under a warranty period and B) something happens. With a cooler and judicious driving, I think you're pretty safe even in smaller vehicles than your mountain of recycled steel.

I always tow in OD with my Nissan Frontier. It's a 2000 crew cab 4wd and a factory tranny cooler. I've towed double stacked 20s and double stacked F18s and my Hunter 23 with it no problem. It is, however, geared quite low so the RPM's running at 65 to 70 are higher than most. I've got about 125k miles on it and a lot of that towing. Other than the miserable fuel economy for a truck that size, it will pull really well for what you would expect of a V6.

I should also mention that my VX was geared insanely low, and had a tranny "lock" indicator light so I could tell if it was slipping.

I can't stand auto transmissions. I've regretted every one I've ever owned.

I tow in 6th gear

Along with adding a transmission cooler install a deeper oil pan on the transmission to increase the amount of fluid. Some trucks and RVs already have a deeper pan so check the stock size before buying an after market model.

I just hook up and go, almost forget there's something behind me Just becomes an unwilling participant, lol. Set the cruise on 80 and let it eat... oh how I love the whine of a turbo!

And now its harder to get a manual trans in a light Duty vehicle. The epa rating on a standard trans is worse than an Auto so to get better epa #'s they discontinued the manual on some models. Go to your local dealer and try to buy a f-150 chevy 1500 or dodge 1500 with a stick. Ford completely discontinued it but still charge you for the Auto as an option.