I just replaced the hydraulic pump on my '55 WD45 with a rebuilt and I guess they didn't get the unloading pressure set properly as I blew the packing nut off one of the hydraulic lift rams (lots of pressure now! ;-). (I know how to deal with the pump problem.)Its my understanding that the packing nut is never suppose to carry the load in the event the lift tops-out, yet it appears that this ram did just that. The blown ram had the bushing stop in the guide assembly oriented towards the bottom of the cylinder (frame side) so that when the ram topped-out, pressure was applied through the bushings and packing to the packing nut which blew out along with all the packing and one bushing as well. From the exploded drawings in my manual, the piston guide bushings are shown between the cylinder body and the guide assembly while the packing are on the lift side, indicating to me that the bushing stop in the guide assemble should be oriented towards the *lift* side of the ram so that in a topped-out condition the hydraulic pressure is transferred through the bushings to the bushing stop rather than to the packing nut. On the other hand, looking at the exploded drawing for a remote hydraulic ram shows the bushings on the *lift* side of the guide assembly right against the packing, just as mine was (mis?)assembled. Which is preferred? My service manual doesn't say in either case. I'll have to replace the packing nut as the threads where stripped out. The guide assembly doesn't appear to be damaged and I've reinserted the bushings. I'll have the new packing nut and replacement packing for both rams by tomorrow evening ([knock][knock]) so any opinions on the assembly would be very helpful. Thanks in advance. David
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