I've got a 1999 f150 5.4 4x4 that just recently started slipping. Usually from a stop. Accelerating or slowing down at a yield than accelerating again. The engine will rev up but no power will be put out to the wheels then it will shift hard. It seems like I can avoid this problem sometimes if I sit at a stop longer. It's throwing several codes. P1000... Which the truck has had this code for what seems like forever, can't get it to go away. Don't think it's tranny related tho. The newest codes I pulled that showed up right after this slip accrued are P1740 (torque converter clutch solenoid inductive signal) and p0741 (torque converter clutch circ perf/stuck off). By the way I'm running 35s on stock gears which I know isn't good but I plan on running 4.56 gears really soon, just gotta get all these tranny kinks worked out so I can send it to get the gears swapped. Taking the truck to transmission shop tomorrow to get them to take a look at it. Any help??? Thanks in advance!

 

Try using 2 or 1 then once you are moving put in D. I had problems like that, I thought it was done. last-ditch effort I put the Lucas Transmission Fix in where you remove the transmission dipstick. nothing happen right away, well we were going home one of the spark plug blown out going up hill. Got it home & let it sit over the winter. spring came around, so i put it in the shop to fix that spark plug. Well it is working like new, Lucas fixed the transmission some how.

PS: I changed the transmission oil before I put the Lucas in.

There is also a filter that is hard to get to, inside the transmission.

 

Okay so last night I dropped the pan cleaned the pan and magnet. Had lots of metallic goo on the magnet. Swapped the filter and the gasket. Put it all back together and filled it with transmission fluid. Truck ran great afterwards. No slips and the code went away but this morning the dip stick is dry. It appears I may have oil leakin on the back side of the pan. Through the seal from what I can tell. Any tips or pointers on fixing the leak