"After a long (13hours) trip I reduced throttle to idle to slow down. When I increased the throttle again the transmission would not engage until about 1500rpm. Which resulted in a hard push forward. This was reproducible over and over again. I never took the transmission out of gear, I only varied the throttle. It's a newly (~2 years) rebuilt transmission with new oil. It may have been a little over full, but only slightly. Anyone have any ideas?