Have a 98 4x4 with the 5.4 and the 4r100, 228xxx miles on it and believe everythings stock. The other day while driving home the tranny seemed to be slipping in 1st gear. Drop it in manual 1 and it takes off a little better but still has a little slippage. I went home and changed the filter and added 6 quarts on tranny fluid and a little lucas additive. Old stuff didnt smell to burnt and was not alot of residue on magnet. Still have the issue but it seems like when the trucks cold its not as bad. Im sure the heat thins the fluid of course. No codes or CEL/OD light that my scanner picks up. Any other things i should check before i order a rebuilt trans?

 

Well on the way home started shifting hard and the OD light started flashing. Gonna take it in and have codes read.