Towing Issues: towing a Ford Ranger, speed restriction, input shaft

Question
I have a 2004 Ford Ranger and it says in the owners manual not to exceed 55 mph when towing, although there is no mileage or time limit as to how long I can tow without stopping. It has a 5 speed manual trans and I'm wondering why the Ranger cannot exceed 55 when towed. I've seen where other manual transmissions from Ford have so such speed restriction. Do you know why the Ranger does?  

Answer
Scott,

All of the data that I have says 55MPH limit, no distance limit.  It seem to be a function of the transmission design that the transmission cannot get enough lubrication to operate faster than 55 without the input shaft spinning to provide more fluid movement.  

I'm not a transmission mechanic or designer so that is just an educated guess.

Good luck,
Shayne Peterson
MobileHitch
http://www.mobilehitch.ca/