CABLE IS DISCONNECTED

How is the inching spool adjusted? I'd completely back off the adjustment & see what the pressures do.

When you replaced the drum did you get a complete assembley?
The thicker metal end band can go in backwards and not allow discs to seat properley. This will give you a low pressure.

think it might just be possible that the new pumps (built-in) relief valve might be defective?
you did install a new pump right?

I know there was a problem with the splines stripping out when they first came out. Did you use OEM parts? Maybe there is some metal stuck in the control valve but you would think it has been flushed out by now.

The clutches are in good condition. The forward clutch drum striped the slpine. We replaced the forward and reverse drums. We also used a transmission overhaul kit to reassemble. The fluid was never burnt or had a lot of metal. We only have 50psi at idle. The manual said it needs 107psi. At full throttle we get the max pressure 200psi. When the pressure go past 110psi the clutches lock up in forward and reverse. Do we have a valve body problem? We have disassemble it and cleaned a few times and can not find any problem.

What happened to the clutches? Was the oil a mess? Could the pump have been worn where it needs more than a gear? How does the transmission react at those pressures?

strainer is clean and not damaged, the sump filter is also clean. all lines and pick up tube is clear. We have also replaced the pump gear.

I have seen other posts about there being a strainer in the control cover. I wonder if yours is clogged? I am not sure about the location.