980G S/N OF WHEEL LOADER=AYT00249 Hye all. Was wondering if anyone knows the spec for the transmission solenoid coils. Wanted to check the resistance on each of them for inspection report. Found a few models that was installed on the same transmission control valve. Not sure if these are correct for the machine model. But the machine is running fine. Solenoid PN: 524-2035 - installed for clutch forward/reverse/speed 1/speed 2/speed 4. Solenoid PN: 302-3811 - installed for clutch speed 3. When checking, 524-2035 coil resistance was around 5ohms if I recall correctly. While 302-3811 resistance was somewhere around 8ohms. For 302-3811 solenoid (alt PN 147-5399), found the spec on the electrical diagram. Spec is around 8.15+-0.6 ohms. If anyone could share a reference from CAT for solenoid 524-2035 coil resistance would be greatly appreciated. Thanks in advance.
The detail of 302-3811 being replaced by 524-2035 was covered in a publication dated September 2020 Titled "New Transmission Solenoid Valve is Available" covering six different solenoid valve Part Numbers of which 302-1811 was one. The text reads "A new transmission solenoid is now available for the machines listed above. The new solenoid has improved durability. The new transmission solenoid is only applicable to individual clutch modulation (ICM) transmissions, and electronic long range transmissions (ELRT)." I cannot find any specification for the coil resistance of the 524-2035 solenoid valve, but seeing as you measured the same value on five identical P/N coils fitted to the transmission on your particular loader then it would appear that 5 ohms must be correct. Why the difference in resistance to the former Part Number I have no idea.
I forgot to mention that the update from the 147-5399 solenoid valve to 302-3811 was made in December 2004, about 18 months after AYT00249 was built.
Thanks Nige for the info! Greatly appreciated.