Here is a clipping from a trailer guide I found online. Hope it helps.
-Bryan
Explorer 2Dr SOHC 4.0 V–6 5,080 (a,d,h)
Explorer 2Dr (4WD) SOHC 4.0 V–6 4,860 (a,d,e,h)
Explorer 4Dr SOHC 4.0 V–6 5,860 (a,d,e,h)
Explorer 4Dr (4WD) SOHC 4.0 V–6 5,640 (a,d,e,h)
Explorer 4Dr 5.0 V–8 6,700 (d)
(a) Requires automatic transmission and towing package; manual transmission rating substantially lower. (b) Requires 3.31:1 axle ratio. (c) Requires 3.55:1 axle ratio. (d) Requires 3.73:1 axle ratio. (e) Requires 3.98/4.09/4.10:1 axle ratio. (f) Tow rating of Splash may be different. (g) Fifth–wheel rating; ball–hitch trailer weight limited to 10,000 pounds. (h) OHV 4.0 V–6 rated 500 pounds lower. (i) Must be equipped with heavy–duty tow package. (j) Requires automatic transmission cooler. (k) Requires 16–inch rims. (l) Automatic rated slightly lower.