Silage trailer pto

That was my first thought... If its a dual drive with one motor trying to turn one way and the other trying to turn the other way then nothing will work.

 

Heres a quick lesson .. all hyd systems have a relief valve or a bypass built in the system some where .. now maybe its on the truck.. but since you tried 2 different trucks .. its Obviously a problem in in trailer.. a hyd system.is designed to operate at a certain pressure .. if there is a restriction of any sort it should cause the relief valve or the bypass to open to keep the pump from building to much pressure but its cause your pump to build pressure to the point it wants to stall the engine.. which if I was to guess your issue is related to the motor your replace ..are you sure the chain is not bound up or the drive sprocket bound ? I would go through process of elimination.. I would disconnect the floor chain and see if both motors turn when the PTO is engauged if they do then.it's a Mechanical problem with the floor chain .. if not I would Isolate the motor you replaced and see if the other motor turns when the PTO is engauged .. if so then I would triple check how the new motor you replaced 1st was plumbed and start backing to the front of the trailer

 

With the floor chain disconnected ?

 

Is there a flow control on that ?