Tractor Repair: pto 300 & 784 international tractor, clutch plates, international tractor

Question
The pto on my tractor will stall when it gets under a heavy load but it will not chock the tractor down it makes a whining noise and stops turning I stop the tractor it will go back to speed and be ok until I get it under a heavy load I thank you for any input you can give me it is doing the same thing on both tractors

Answer
 Hello,

  The pto clutches are slipping, so they will have to be rebuilt with new clutch plates and piston seals.  The pto pressure will have to be checked also to make sure there is enough to prevent it from happening again.  There should be at least 200 to 240 psi.

                        Arnie