2003 Superduty 5.4 Auto

[Galaxie]

Is the trans a 4R100 or 5R110W?

[mudfuel06]

Should be the 4R100, I don't think they went to the Torqshift until 05.

[Galaxie]

^^^^^^Cool! So does it take Mercron SP or LV?

[mudfuel06]

It actually takes Mercon V, but I think anything that is equal to, or better should be fine.

[Galaxie]

The truck, trans and origonal fluid has 160,000 miles on it. Any suggestions on how to approach this?

[mudfuel06]

Originally Posted by Galaxie

The truck, trans and origonal fluid has 160,000 miles on it. Any suggestions on how to approach this?

I would just drain the pan, the convertor and the lines. I am of the opinion that if you flush it, you may knock something loose and have to rebuild the tranny prematurely. Just my .02.

[Galaxie]

Oh cool, so this converter has a drain plug? (unlike my truck!)

[mudfuel06]

Originally Posted by Galaxie

Oh cool, so this converter has a drain plug? (unlike my truck!)

It should, I know that mine had one, just a pain to get it lined up with the insepction hole to drain it. You may need to get a pry bar to turn in if you're underneath the truck. I've heard that you need to get a new plug, but I reused the one that was on it and never had a leak.

[Galaxie]

Does anyone know how many qts will come out if i drain pain and TQ converter?

[jesilvas]

If it's a 4R100 then a pan take about 7-8qts. TC not sure.
The best way to flush is to somehow refill the transmission with new fluid at the same time it is pumping out old fluid. We had a machine that did that at my old job. It never pressurized the trans, just let the TC do the work. Now if a machine actually does the work of flushing, then I wouldn't use it. I used our machine to flush mine at 300k miles and it's still working great.
And a 4R100 takes DexIII.
The trans dipstick should say. DexIII if it's a 4R100 and MercV if it's a 4R70.