I Have a Kubota g1900. all of a sudden the PTO works only when I manually push it all the way forward. The minute I let

It sounds like something is preventing the lever and/or linkage from shifting fully to the PTO position so the detent ball can hold it in place. Check for bent lever or linkage. With the machine OFF, and the lever and linkages disconnected, see if you can move the shift shaft fully and feel a detent that locks in place. This will confirm that the shift fork and detent are in good condition and not damaged. If you can not feel a detent, it may have broken, or the shift fork may be bent.

Follow all Safety and Maintenance Procedures as illustrated in the Operation and Maintenance Manuals for your machine! Remember to click ACCEPT.

Some have linkage, some have a cable. Yes, disconnect the cable from the shaft PTO shift shaft and actuate the shaft manually to see if it will engage the PTO and feel like it slips in to a detent, similar to how a manual transmission feels when put in to a gear. If it does not feel like this, there could be as serious of a problem as a bent PTO shift fork limiting the shift shaft range of motion from reaching the detent, or it could be as simple as the detent spring being broken. Either way, you will have ruled out the cable and lever from limiting the shift from reaching detent and full gear engagement. A deeper inspection in to the transmission will be required.