Just sharing my experience here. If you guys recall, I was never really happy with the way my tranny was shifting after the rebuild. I tried a few tricks with different accumulator springs, but nothing really seemed to make me happy. (I'll admit I'm a fussy S.O.B.) Someone suggested to me that I should put back that 6th check ball in the valve body that usually gets discarded to soften my light throttle 1-2 shifts. (they were very harsh) So I did that, and at the same time I tried a different factory style 1-2 accumulator valve spring. (moved from outboard side of valve to inboard side) After trying that, the light throttle shifts got smoother, but at the same time the 1/3 throttle shifts got sloppy. And for some strange reason, the full throttle shift points dropped from about 5,400 to 5,000 rpm and that full throttle chirp I used to get was gone. :ball: So I tried this again.......ripped her apart one more time. This time I replaced the stock spring with a fairly stiff one. That seemed to do the trick......now she shifts at around 5,300 and chirps the tires every time! :Brow: I also noticed the sloppy 1/3 throttle shifts have gotten firmer.......now everything feels just right. :TU: Although I still don't understand how the accumulator could have an affect on full throttle shift points, I guess it pays to be persistant......
The checkball that is usually omitted (#1 in ATSG manual) is not in the 1-2 circuit at all. It is in the 3rd gear circuit so it will not affect the 1-2 shift. It is considered non-functional. The accumulators work at all throttle angles unless they are blocked. The accumulator valve may have been leaking pressure from the governor circuit causing a lower shift point.
