I'm not saying that it is a 1-2 accumulator issue, but it is something to keep in mind and I would certainly check it if you have the pan off. All you need to remove is the pan and filter to access the accumulator. Check out
this link. About 1/3 down the page is where he shows the accumulator.
I used a 6" C-clamp to hold the accumulator in place - you NEED a good pair of snapring pliers to get that big monster out and back IN (I paid about 17 bucks for a decent set of pliers, for instance. Well worth it). There's a lot of tension in the snapring.
The newer accumulators are designed to not eat the bore, so that's a nice upgrade, as are some fresh springs (dont leave a spring out, as some people like to post. Most of those guys end up replacing the spring after awhile anyhow). The accum and springs are not expensive if you dont get them from your dealership (even then, you should be able to get the accum and both springs for under 100 bucks). Bulkpart.com has decent prices - I've ordered from them before.
The other thing that's easy to swap is the shift solenoid pack. And they are not too pricey either (25 bucks or so from Bulkpart IIRC). Lastly, get a rubber over metal trans pan gasket. It's worth 5 times its cost (about 10 bucks IIRC) compared to those crap rubber or cork gaskets you get with a trans filter. Oh, get a new end cap thingie (it is what sits against the snapring. It has a seal and is cheap. They get torn up).
Here's a
blow up diagram
Another article with pics that might help
I should have noted that with those articles, you're not doing all that work - just go to the parts about swapping the 1-2 accumulator. The pics and narratives were helpful to me.
TCCoA and clickclickracing.com are two great places to search for AODE/4R70W trans info, if you want to put up a thread or search for more info based on your symptoms.
Good luck.
