I'm working on a 2955, just rebuilt transmission, all new bearings, seals, etc. But the fwd won't completely disengage. At the port on the side of the shift cover the pressure is 150 psi. The solenoid is working - pressure is 130 psi at idle with switch in disengaged position, flip the switch pressure drops to 0. With the engine running at about 2000 pressure increases to 145. If I put a pipe wrench on the shaft with about 2-1/2' of leverage I can turn it. Also I tested for internal leakage - pressure difference was 5 psi. Clutch has all new seals, 1 new internal and 1 external splined clutch disc (all the rest were fine just those 2 were worn). Also I added shims behind the low pressure relief valve to try to increase the pressure but it didn't change. Any ideas what could be wrong?