I have 140H Cat motor grader that wont go forward or reverse. I'm trying to find out how much voltage the solonoide should have? I turn key on and they get really hot real quick.
The solenoids are supplied from the transmission ECM, so the voltage is likely to be not much, probably 8v stabilized. The standard test is to check the resistance of the coil - it's 8.7+/-0.4 ohms. If all the solenoids are getting hot quickly (there are 8 of them I think) I'd guess your problem is not in the solenoids but in either what supplies them (the ECM) or in the wiring harness between the ECM and the transmission. All 8 solenoids use one of 2 ground cables to connect back to the ECM. Maybe the fault is in one or both of those cables. Is the machine showing any Active Diagnostic Codes..? I could go into more detail with a Serial Number - there are 12 different Serial Number prefixes to choose from.