2000 Ford Expedition - Automatic Transmission transmission model: 4-speed 4R70W automatic - First, my transmission was making a whining noise, only when under pressure like when putting on the gas going up hills, not knowing what the problem was it sounded like a loose coin under the dash, finally getting frustrated with the issue and my wife insisting it was coming from the engine I had my brother listen for the noise while I pushed on the accelerator in neutral, you could barely hear it in neutral or park, no answers. We drove it around and found that it only made noise when the transmission was out of neutral so we went to Autozone, bought a bottle of (i cant think of the name but it's red one side/yellow the other) transmission conditioner. Immediately after using the fluid, the noise was much easier to hear, you could hear it in park, neutral, was it the transmission then? So we dove under the truck for a listen much easier to hear, and sure enough it was coming from the transmission. After reading posts about the whining noise I suspected the transmission pump, after all the OD light off started blinking at that point as well. Took it to the transmission shop and they said $1900-$2400 to rebuild it as it was slipping in 2nd/3rd gears. I asked about the pump and they said surely the whining noise was coming from shreads of metal from 2nd/3rd gears choking up the pump. But, they never took the pan off, they got the information from a read out saying the gears were timing wrong. So, in mine and my brothers infinite wisdom, we figured if we were going to pay so much anyway, might as well take the pan and valve body off and see what we could find. First, pan was filthy, obviously never changed before with 150,000 miles on it, the plastic plug was still in the pan and there was plenty of "goop" on the magnet, i don't think there was a chance it could collect any more metal. The filter looked pretty bad too. There was a shred, twisted piece of metal about 2 CM long stuck on what I would call a plunger like circle, after taking the small and huge compression washer/rings off, the plunger slipped out and had a big green spring on it. In any case removing this enabled us to get that shred of twisted metal out. We then cleaned the pan, new filter, replaced everything, using a jack to push the spring loaded plunger back up we got the washers back on. Filled up the transmission with fluid and wheee!,.. no whining noise. it actually feels great; up until its time for overdrive to come on. Overdrive comes on and the transmission slips, not just slips but just revs the engine, hit the odoff button, back in gear, od button on again, transmission slipping. The truck drives just fine as long as OD is off. In any case - no whining noise yippie, but no over drive either, what could be my next step? I dont mind driving around with no overdrive, its only a difference of about 500 rpms if it saves me $2400. What should be my next step here, is OD fixable? I'm not sure if cleaning all of the 1/2" thick "goop" off the magnet or The part that had the small metal shard stuck in it was the noise issue, the part with the shard stuck in it was part 116, or possibly 113 (overdrive servo cover) bottom of the schematic - pdf schematic (here) when putting this cover back on there was two crevices the retaining ring could possibly have fit on, since the lower crevice didnt look right we went ahead and pushed it up to the higher crevice, I dont think the lower crevice could have fit the retaining ring, could have been wrong.

Thanks!

 

I believe you're missing a piece somewhere in that OD servo system or it's still stuck in the valve body somewhere. Will recheck your description more thoroughly and see if I can determine if you got it out.

 

I'll try to be more clear about that shred of twisted metal. The shaving was visible from the valve body side of the piston however stuck between the side of the sealing ring and the piston wall. the piston prior to removing the shaving would spin freely but it looked important to remove the shaving. The shaving was as skinny as a paper clip, about 3-4 CM long, and was coiled somewhat until trying to pull it out it pulled straight so it was flimsy not sure what it was part of, it was like someone took a chisel and chiseled a sliver part of the piston wall perhaps. We took the retaining ring off and it removed cleanly.