Hi, It has been a while since I've been on this end of a thread, but here goes.
21K ago 47RE began intermitelly dropping out of lockup at road load. Was not nearly as bad under load. At that time New output RPM sensor, the wiring connector, OD solenoid and transducer replaced, Brake switch, two complete reman valve bodies were installed, The clutches were smoked when pressure gauge hose burst and dumped fluid, A complete O'haul with virtually no wear found, new heavy hauler TC, all grounds and terminals inspected, a new alternator, upgraded charging wiring and installed additional grounds. An on and on. The end result was addit one extra pint of ATF cleaned up (????) the situation and worked fine for roughly 20K. Now it's back. At road load it unlocks for a split second, just enoughto see RPM spike 25-50 rpm. Then back into lock. May go ten miles before happens again or do it almost constantlly. I'm going to add a little more ATF and o'fill and shield as much wiring as possible for testing. Any suggestions??????????

 

You need to get a noise filter from DTT.

 

I was going to suggest the same basic idea. Get a noise filter, or you can try and wrap the ground wire coming off the back of the alternator with tin foil and see if that helps.

 

Check out the thread stuck at the top of this forum called, "Common Problems...". I have a post containing many solutions to this lockup/surging problem.

Good luck.

 

VooDoo and Black Majic!!!!!!!! a 6x12 inch piece of tin foil cures along with special inccantation..... Shielded alt output wire. Seven hundred miles later, never a slip out of lockup. Will select a formal fix and report. Not paying 75 dollars for a $3.00 capicator. Thanks for input guys.