Hey everyone,

Looking to get some help and guidance.

have a 2003 F-150 Lariat FX4, 5.4L, 470RW. The truck has 89,000 miles on it. No transmission service has ever been done. I bought it brand new. In all aspects, the truck is very well-maintained by me.
Recently (about a 1000 miles ago) I started to notice a slight shudder, sudden loss of power, etc. For whatever reason, I assumed it was the MAS/throttle issues. I cleaned those out completely and some of the loss of power issues went away. However, the shudder (esp. when the gears upshift) remains. I also started getting the sudden lurch forward when going from PARK to D3. I'm convinced that it's time to service the tranny. Since the truck has almost 90K miles on it, I'm not going to do a full flush. I was thinking of just dropping the pan, letting it drain, and replace the filter and gasket, and refill with 4-5 quarts of ATF. Btw, I went out and bought 5 quarts of Royal Purple ATF (meets Mercon V specs).
Then, I came across a thread where someone said they drained almost 12 quarts (from the original 15) when they dropped the pan. Not sure if they drained the torque converter too. I don't even know if my model's torque converter has a drain plug. But how can this be?

I thought that a simple drop-the-pan job was about 4-5 quarts. If it's really 12 quarts I'm gonna drain, then I'm 7 quarts short!

What do you guys think? How many quarts should I have handy if I drop the pan and let it drain? How many more quarts will I need if I manage to drain the torque converter too?

Thanks in advance!

 

A 2003 doesn't have a TC drain plug. I also would not put 5 quarts of RP in with 9 quarts of old original fluid. Get a complete exchange done with a machine or use this procedure:

http://www.jordanpeterson.me/book/ch...smission-fluid

With 89k, if your spark plugs have never been changed that could be at least part of your drivability issues.