TH400 No 2-3 Shift

[rcazwillis]

Last big hurdle on Zane's 71. Transmission will not shift into 3rd.
History: I built it. Have built many without issue, mostly for track use. Have built some with issues, but always managed to sort my error.

Symptoms:
Won't shift into 3rd. 1-2 shift is good.
Reverse shutters a bit at first, does not engage quickly, but will engage. Does not slip once engaged.

Two "upgrades" during build:
Dual feed direct clutch: Removed seal between two chambers. Failed to plug the reverse hole in case. Assumed this was the cause of both issues. Plugged it over the weekend, still won't shift into 3rd. Checked governor, All weights move freely, valve moves freely, teeth are all good, gear on output shaft all good.
Plugged 2-3 accumulator piston in valvebody removed spring under piston. Verified it was correct this weekend.

Ordered pressure gauge and will check pressures per the ATSG manual this week.

So where do I go now? Seal problem in the direct clutch pack? Valve for 2-3 reassembled wrong? This would not make reverse shudder, not engage well. Burned up direct clutch pack when case not plugged?

Is there anything I have not checked before tearing it all back a part.