Well, I have waited about 3 weeks to have an engineer at Ford ask around about the 99 Ranger acting like it got rear-ended when in gear with the brakes applied. No one at Ford that he talked with had ever heard of such a thing. While I waited, we would hit the switch on the overdrive and turn it off when coming to a stop. That seemed to help but I really didn't want to do this forever. The mechanic I took the truck to said he has never heard of it but would run some diagnositics. No Codes showed up so he dropped the pan, cleaned the pan, changed the fluid and filter. The only thing he saw was some film on the pan, everything else he could see looked ok. I drove it about 20 miles, stopped at 10 stop signs and or lights, sat in a couple of parking lots with the brake on while in gear. Nothing.
I will let you know how long this lasts.