Hi Guys, I have a 2000 F150 that I just picked up a few days ago. it has the 4R70W tranny in it mated to a 5.4 and 4x4 with about 200k. Its a Lariat. Anyways truck runs and drives great and when I test drove it the seller had just driven it to the car wash.

Anyways, The next morning I went to leave home and had a perfect 1-2 shift but 2-3 didnt seem to happen so I pushed the gas a little harder and wound it to about 2300 rpm then it went to shift into 3rd and it was very slow but then it shifted and continued to shift into every other gear perfect. Every time I stopped and started after that 1-2 shift was perfect, 2-3 shift was perfect and 3-4-od was perfect. So im kind of puzzled.

This happens every time the truck sits for at least 3-4hrs or more in 50 degree weather and the tranny fluid has time to cool to close to air temp. But it only does it once... after it makes the one funny shift into 3rd then it doesnt hesitate anymore for the rest of the drive. I can drive 1/8mile have the very hesitated shift into 3rd which sometimes it will go to shift into 3rd and if I stay on the gas it will rev up like its in neutral and then go into 3rd. Or When I know it should shift into 3rd and I stay off the gas for 5-10 seconds then it will shift into 3rd and then I get back on the gas and everything shifts good from there on out. The thing is though is like I said drive just a few hundred yards when the truck is cold and then have a funny shift into 3rd and then I can immediately come to a full stop after it shifted into 3rd and then it will have a perfect 1-2 shift and a perfect 2-3 shift and so on. So its weird how after it has one funny shift then it will shift perfect after that for the rest of the drive even if the fluid is still relatively cold. The fluid has been serviced not too long ago... not recently but evidently not too long ago and smells normal.

Does this sound more along the lines of a lazy shift solenoid? or I just recently read something about an accumulator piston or something of the sort? Would these be a probable cause or would we lean more toward clutches? I do not want to start throwing money at parts and tranny fluid for repairs on stuff that isnt very plausible. Like I said just one weird shift than everything is great and 100% normal from there on out.

Thank you for all the help everyone.

 

Anybody?

 

If it were me, I'd change the fluid and filter (again?). The 2000 has a drain plug on the torque converter so you can drain all of the fluid. Only cost you about 12 qts of fluid.

 

I would also try the service/fluid change getting good fluid. Do U have a tune, if so put it back to factory and drive it 100 miles.

 

Good to know guys! Thank you. Truck does not have a tune or anything. I think I will try a tranny flush and try draining the TC too. The truck was previously owned by an Art teacher and fixed every little thing that the truck ever needed which was nice. New U Joints on all ends, new sway bar links etc. so that was good. Since I have been driving it daily it doesnt hesitate nearly as much before or rev up in between shifts or anything. It does still hold out the shift for quite a long while, up to about 2000-2500 rpms but then it shifts and after that first cold shift then it shifts perfect after that. So the daily driving must be helping but still going for a fluid change. Was just curious what it could be and why only on the first cold shift and after that its flawless... Slow shift solenoid, the piston accumulator or what?

 

I'd suspect wrong viscosity or incorrect formulation fluid.

Do NOT flush it, just drop the pan and drain the TC. Use Mercon V fluid.