4R70W 1-2 shift error

[mneal]

I have 97 4.6 4x4 with the 4R70W and the OD light started to flash over the weekend. I have recently purchased the truck and the previous owner said a local shop re-did the tranny ~10k miles ago. (currently truck as 122k) I took it to local Ford dealer and they said it was 1-2 shift code. (they didn't tell me the exact code.:-(. The recommend a 1-2 shift accumulator. Any thoughts from the experts? I replaced the TCC right after I bought the truck to solve a TC shudder with the help of those in the know here...asking for assistance once again. Is the 1-2 accumulator common and is it something I can do on my back in my driveway. (I have reasonable mechanical aptitude)

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[mneal]

I took 1-2 accumulator apart tonight, everything looked pretty OK...no broken springs etc. Bore had a slight bit of roughness but very little. The accumulator was old style (aluminum w/ o-rings) . I have the updated piston assembly and springs ordered from Ford Dealership and they will be here tomorrow. I was able to remove it without removing VB, I am hoping I can re-install it with leaving VB in place...is that possible? Other than polish the bore slightly with scotchbrite is there any tricks? The inner (upwards) bore was not as easy but I did get a little polishing done, other than no scoring/roughness it that all I need?

[mneal]

Update: I replaced the 1-2 accumulator piston and springs with the updates version. (had older aluminum style). Polished the two bores with some scotch-bright and re-installed...drove couple miles 1-2 shift felt good...2-1 downshift felt good...I am starting to be pleased then bam..OD light back flashing. The the shifting is odd (I assume it goes in a "limp home mode". I didn't replace the cap and/or cap o-ring and I thought maybe that was dumb since I had it all apart. Also I had some difficulty getting the cap past the preload and install snap ring but I eventually got it. I was afraid I harmed the cap o-ring once but removed it (before I had snap ring in) and the o-ring looked OK. I dunno what else to try.......thoughts from the experts?

[mneal]

Update: I think it is fixed. I replaced the 1-2 accumulator cover with updated one and the solenoid pack. I drove the truck about 30 miles tonight as well as a ton of stop and go (1-2 shifts) in my neighborhood and no codes...shifts smooth and nice..best since I have owned it. I am crossing my fingers because there were times last week it would go a couple miles and not throw a code then would so hence my extended test drive. I found an easy way to install 1-2 acclamator. I could use a 5 inch "C" clamp and hold the cover and easily install the snap ring...I tried to take a picture but not sure it it is clear or not in picture. And I can't figure out how to attach the pic to this post.

[T Ellenberger]

I remember using a small bottle jack to lift the cap into place to put the spring back in to the slot.