Curious if anybody has seen this before. I found an old thread but not much of a resolution.
I rebuilt this unit with a pretty normal recipe I'd say. Boost valve, rollerize output, direct clutch springs and hole drilled in drum, dual fed directs, line to lube mods, shift holes drilled etc etc. Ptc single disc converter. Also replaced the solenoids with acdelco replacements and the internal harness with a rostra iirc. This is also not my first 80e, and I've done some 60s, 350s, 400s, ford 4r70w and 4r100 along with some fwds.

It seems to be working fine although I haven't driven it more than a few feet. But if I pull it down in manual first it seems to be locked like a transbrake. The ecu is a terminatorx max, my first step will be to make sure the harness is pinned right as I know they've been wrong before. But im curious if anyone has seen this, or anything internally that could do it?

 

More info- 3 and 4 accumulator are deleted with a plate. Replacement sep plate from transgo, not the 3 piece unit. Used pieces from transgo sk kit but not the pressure relief valve. I seem to remember removing the 1/2 accumulator seals for some reason, but i may not have. I built this unit about a year ago

 

When you start making your own mods, you need to know why.
Look at your 1-2 accumulator seals again and determine what you did there and why.

 

Thanks Jake i appreciate your help. I left the bigger seal off the accumulator by mistake. I found the new seals still in the package which is why I thought I left them off or just didnt replace them. I will study the manual low circuit

But that fixed it. It works great now and I can tell it has 1st gear where I think it was starting in 2nd.

 

When those seals are left off and a stock separator plate is used, it creates a cross leak between the 2nd gear and accumulator circuit.

Some of the recalibration/shift kits out there say to leave them off in the instructions, but that’s only because an aftermarket separator plate that comes with the kit is being used in conjunction with the omission of those seals.