I have a 93 4.6 and 4r60w in 46 merc. On a recent trip we hit a bump and over drive shifted to 3rd. Button would not work. Short time later o/d came back but went out on another bump. Checked wiring then pulled pan and put a shift and tcc selinoid in no bad stuff in the pan and check o/d servo no problem there. Going up the walls looking for answers. Help.