Anyone here with experience on P&H 60 ton cranes? We have one that won't swing either direction without serious jerking movements. The original voltage regulator assembly has been changed out for a solid state assembly and none of the voltage and ohm readings seem to be the same as my troubleshooting guide that was with the original assembly. Need help.
P and H 60 ton crane is a pretty wide range. You will get more help if you can give us a year/ model/ serial #. 60 ton could be a lattice crawler, lattice truck, hydraulic truck telescopic boom, rough terrain crane, pedestal crane etc. etc. P&H manufactured cranes from 1887 to being bought by terex in 1995. So a little more info on your end might help.
Reading and seeing swing jerking, I immediately thought friction crane with warped swing drums or shoe adjustment issue. Then read the part about voltage regulator and thought Nope not friction
I can get some more info. It's definitely a lattice crawler, early 1970's. I can get exact date and serial.
Just came across this hope you got it already
P&H 670 with Magna Torque swing. It might be something as simple as wet or oily frictions .If they are oily brake clean first and then run them in, Any P&H ive ran from hydraulic friction to Magnatorque needed a good run on the frictions with the house lock on every morning to dry out. High Rpm and just ease them in gently,both ways for a minute or 2 and your good for the day. They will take you for a rough ride otherwise. These old old cranes have feelings you need to learn and respect.These are a couple of P&H s ive run over the years they both like thier swing frictions dry.