After restoring an MF40, the gears would grind when attempting to shift, indicating a warped or sticky clutch pack. I split the tractor and replaced the discs and plates in both packs. After reassembling the tractor, the transmission worked flawlessly with no grinding and smooth engagement into forward and reverse. After about 30 minutes, and numerous forward/reverse cycles (allowing engine to idle down before engagement), I lost reverse. I checked the system pressure and it was steady at 156 psi. I then checked pressure after engaging the forward clutch and it dropped momentarily and returned to 153 psi. But, when I engaged reverse, the pressure dropped and never recovered, indicating a loss of pressure integrity in the rear pack. I split the tractor again, pulled the packs and immediately found a large circumferential crack extending 2/3 around the rear clutch pack cylinder (at the base).
I have found replacement parts ($$$) and am prepared to put the transmission back together. Obviously, I don't want the new cylinder to fail the same way, and have been unable to determine the cause of failure. I found no indications of anything assembled incorrectly and it worked perfect, initially. It seems the failure would indicate excessive pressure within the cylinder, but the system pressure has always been within limits when tested.
Sorry for the long post, but if anyone has any ideas/experience that they might share, it would be appreciated. Although this is my first post, the forum has been a tremendous benefit throughout this restoration. Thanks for your help!
I have found replacement parts ($$$) and am prepared to put the transmission back together. Obviously, I don't want the new cylinder to fail the same way, and have been unable to determine the cause of failure. I found no indications of anything assembled incorrectly and it worked perfect, initially. It seems the failure would indicate excessive pressure within the cylinder, but the system pressure has always been within limits when tested.
Sorry for the long post, but if anyone has any ideas/experience that they might share, it would be appreciated. Although this is my first post, the forum has been a tremendous benefit throughout this restoration. Thanks for your help!