Bill, having a 98 Ford Ranger I can tell you that while the Service Manager and the Ford Towing Guides are good starting places, the best and most definitive source of the spec for YOUR Expy will be in the owner's manual, plus some reference to the door sticker and VIN
to determine exactly how YOUR vehicle is equipped and rated.
For the Ranger pickups in '98 alone, there are !!! 60 !!! combinations of engine size, tranny, body (cab and bed) and rear end resulting in tow capacities ranging from a high of about 6,000 lbs to a low of "Not recommended for towing".
My truck happened to come with a towing package that includes separate circuits for the trailer lights
(Ford plug-in gizmo for Flat-4 connector available), additional transmission cooler and additional power steering cooler. I know it has the larger auto transmission and the larger differential, besides having the appropriate gear ratio for towing. You can tell if you have extra tranny cooling by looking for a smaller cooler near where the trans lines enter the bottom of the radiator on the passenger side; the power steering cooler can be seen on the driver's side, a much smaller cooler.
For the 98 Explorer, there are 39 combinations of engine size, fuel system, tranny, body (2- or 4-door) and rear end resulting in tow capacities ranging from 1,940 to 6,700 lbs in the owner's manual.
In addition, ALL the tables and combinations for the 98 Explorer contain this:
"Notes: For high altitude operation, reduce GCW by 2% per 300 meters
(1 000 ft) elevation. For definition of terms and instructions on
calculating your vehicle’s load, refer to Vehicle loading in this chapter.
Maximum trailer weights shown. The combined weight
completed towing vehicle and the loaded trailer must not exceed the
Towing a trailer over 907 kg (2 000 lbs.) requires a weight
That last note, combined with the body style, implies to me that Ford has some concerns about wheelbase on the Expy (the 2 door is 10" shorter than the 4 door) and excess weight
on the rear. If this were my Expy, I would use a Reese WDH with the dual-cam anti-sway control even if my trailer weighed under 2,000 lbs. I would also install the brakes. Unfortunately the 98 stuf wasn't wired for the brake controller or the battery
charge lead, so you will have to do that yourself (or get it done).
The first note proves what the Service Manager said. Generally, reducing the GCW means reducing the trailer weight because the TV, fuel, luggage and passengers aren't likely to change much.
If you don't have an owner's manual, go to the Ford web site and download
one. If you are technically inclined, go to EBay and buy the Service Manual on CD.
Ford Truck VIN Decode
Ford Truck Door Jamb Label Decode
A general note on transmission temps, gleaned from the experience of folks on Yahoo Scampers is that if one's automatic transmission's torque converter becomes unlocked, esp when climbing grades, the temps will immediately start to climb due to the slippage. This seems to be where having a transmission temperature gauge will be very handy, allowing the driver to shift down, slow down or both. I personally find it difficult to differentiate between gear shifting and converter lockup, but those folks report that when the lockup is lost, the rpm will immediately rise, soon followed by temperature rise.