Hello, last year my gear light would flicker on for a half second, I would catch it from the corner of my eye. In the fall it stuck on for the most part only going off for a second. No gear changes with it on. I checked codes and found 251, left track speed sensor. I checked the plug and it had oil in it. I changed the sensor, and now the light is on solid. Sensor in the machine is 183-4584 Replacement 183-4584 aftermarket. Cat says it is 319-6491, so i bought that one now and waiting for it to arrive. But it shows that they are the same sensor and the numbers crossover. Any suggestions on what to look for next. Help and experience is appreciated. Jim
Correct on the 251 Code being related to the LH track speed sensor. Oil in the electrical connector is a familiar failure mode. The 183-4584 was updated to 319-6491. However for use on a D5G the required Part Number is 360-0453. I would suggest that you exchange the 319-6491 for a 360-0453, using the Service Magazine as justification. Did you buy the additional parts required to installed the updated Part Number.? The latest P/N of sensor is not plug & play. See attachment.
Cat wants to sell me the 319-6491, and not the updated part you are suggesting. Cat sells them for $307 They are used in about 1000 machines and sold for approx. $70 Why get the update when this machine has worked great for 7000+hours with a 183-4584 sensor. If i get the updated sensor wouldn't I then need them both at well over $600? Wouldn't want to do the updated on just 1 side. And thank you for the reply.
What is your tractor Serial Number.?
FDH00679
Attached is the parts list for your Serial Number, in truth it applies for all FDH-prefix machines. 360-0453 is the listed Number. You will find it shown on Page 6. Note the comments from the Service Magazine above. "An improved 360-0453 Speed Sensor Gp is available for the machines that are listed above. The improved speed sensor group is more compatible with the G-series and K-series Track-Type Tractors." + "The new 360-0453 Speed Sensor Gp is a direct replacement for both the 183-4584 Speed Sensor Gp and the 319-6491 Speed Sensor Gp." Refer the dealer to your machine Serial Number and to the SEPD1270 document uploaded above. I reckon what the dealer Parts dept has done is simply looked for the "general update" for the (cancelled) 183-4584 which is the 319-6491 that they sold you. However if they look for the update under your specific machine Serial Number it goes from 183-4584 in a different direction, to 360-0453. If it was me I would go back and tell them they have sold the wrong Part Number for the machine application. You are paying all that money, you deserve to be sold the correct part for your machine.
If only one sensor has failed you can do the update just on that one. There is no obligation to do it on both sensors if the sensor on the other side is still working. The former and updated Part Numbers are compatible with one another.
If that sensor doesn't work then what? I already installed a brand new 183-4584, the original, that has worked for 7000+hours. And the new 183-4584 didn't shut the gear light off and allow speed changes. This is not an argument, I'm just asking. If I have a few thousand hours left in this dozer why wouldn't the original, or the new crossover 319-6491 be just fine. What could this new 32 volt version do that would be so much better that I have to have the adapter. Also, I don't want to just throw parts at it. I'm buying from different distributors for $60 and 70, instead of $350 for the cat box it comes in. Once I install it I own it. I just assumed it was the sensor because of the code and the plug had oil in the connection. What else could throw that code and cause the gear light to come on. I can't seem to find a wiring schematic for that section of the machine to trace the wires.
Check your message inbox. There is a troubleshooting procedure available for the sensor and its circuit. See attached - however the fact that you found the electrical connector full of oil is a good indication that the sensor failed. try the procedure and see what results you get. EDIT: This may be a cruve ball from left field but check the fan belt condition/tension and measure the charging voltage at the alternator output terminal. these hysstat tractors have been known to pull weird stunts if the system voltage is even slightly lower than what is desired.
I get 14+ volts checking at the batteries, while running. Is there a reason to check at the alternator?
Not really. If you have over 14v at the batteries system voltage should be OK.