P&H Crane with swing controller problem

[SpaceTentacle]

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.

 

[crane operator]

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.

 

[BluewaterLa]

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

 

[SpaceTentacle]

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.

I can get some more info. It's definitely a lattice crawler, early 1970's. I can get exact date and serial.