I purchased my 2003 used from a dealership with 61,000 on her. The dealership had just had the overdrive output shaft, and related seals replaced in it. I understand what this is and how it works, but what I was wondering is if anyone had any idea what would cause this to go bad. The truck has holes in the bed and a small dent in the back of the cab, so I am guessing that the previous owner towed a fifth wheel. Is it possible that he towed to much of a load with the overdrive engaged and that is what actually caused the problem with the overdrive. And does anyone have any idea exactly how much is too much for pulling in overdrive. All I have right now is a 3,750 lb travel trailer so I don't believe that I would be taxing the overdrive very much living and pulling along the Mississippi, Alabama, Louisiana, gulf coast. Much of our area is pretty flat. But I would appreciate anyones opinion of the subject.

 

Towing in overdrive isn't likely to damage the OD output shaft. Now, excessive powerbraking, neutral drops or high boost launches are much more likely reasons for snapping an output shaft.

 

I know a bunch of people who tow in OD, some of them grossing well over 24K, you will have no problems.