A couple buddies and I loaded up my 01 2wd Auto F250 last Friday and headed out to the hills for the weekend. We borrowed an older, smaller camp trailer (20ft maybe) and loaded our 3 bikes into the back of the truck. I had never towed anything with the truck before. Anyway long story short, the trailer felt REALLY heavy behind the truck, and when we got to our site, I noticed a bunch of fluid all over the load levelers and dif. It was coming from the trans. It got warm pulling a couple grades (around 200) and I think it puked it out of the vent. So I luckily found some Mercron ATF in the middle of nowhere and added a couple quarts and called it good. Took it easy on the way home (wasn't really hard on it to begin with) and it still ran hot on the freeway (180-190, and it was only about 70 outside) and dumped out more fluid. I was doing 10 under the speed limit on the freeway, not in OD, trying to be nice to the trans. I got passed by an older non-IC 7.3 with a huge triple axle 35+ foot toy hauler up a grade like I was standing still. I don't get it, it felt almost as if the brakes were on on the trailer or something, and it was putting a huge drag/strain on the truck causing it to heat up, but this isn't the case because I checked the trailer wheels and they were cool to the touch. So my question is, what could my problem be and how can I fix it? It almost seems that I am down on power possibly causing everything to work harder to pull a trailer. But the truck runs great and feels strong with no trailer. I have a 4" straight turboback and the big napa filter intake. Would a large trans cooler help the trans keep its cool? Thinking about a DP tuner but don't want to do that if there is a mechanical issue that needs to be addressed first. It sucks not being able to do at least the speed limit when pulling a trailer without ringing its neck and watching the trans temp shoot up. Thanks.

 

You called it good, but was it? Did a couple quarts overfill the trans? Was it overfilled from the start of the trip?

Overfilling will cause A LOT of drag in the transmission, plus it will force fluid out of the vent.

200°F trans temp is normal when towing.

 

No, 2 quarts put it right in the middle of the "full - hot" when the trans was at temp. It was 2 quarts low.

I don't think it was over full at the start of the trip. If it was, then wouldn't it just vent the excess when it got hot, not drain it to the point of 2 quarts low?

Good to know 200 is normal.

Assuming the trans was filled properly, what would cause it to dump so much fluid?

 

First, tow in OD. You were probably rolling down the road w/o the TQ locked up, and, that will generate tranny heat like you won't believe.

I tow 15k and I'm always in OD, except on large grades. And I run about 170-180 doing it while all stock.

 

I tow in od also,but I only tow about 8500 loaded up. Trans cooler does help a lot. Since I installed the trans cooler and after market trans filter I rarely see 190*

 

If a trans is overfilled the level is high enough that the rotating parts are running in the ATF. This will whip the ATF into a foam, which greatly expands the fluid. That can force out much more than the overfill amount. You easily can be two or more quarts low after running an overfilled trans.

A bad torque converter hub seal will do it.

 

Like Mark said, the front T/C hub seal can let go and puke fluid on the ground. Had this happen on vacation once many, many miles from home. It will leak out of the inspection hole on the bottom of the T/C where the engine mates to the tranny. Some people have had this seal itself back up when it cools down but mine was shot. Puked about 4-5 quarts in a steady stream onto the ground with the engine on. Unfortunately, to replace the $10 seal, you have to drop the trans.