3588 no 1st gear

My 3588 has no 1st gear I took the cover off the top of the housing and the only thing that I could find was that the driven gear on the bottom shaft had no resistance to it. It would turn freely on the shaft. Can anyone tell me what is happening and how to fix it please Kevin

(quoted from post at 16:01:35 03/09/09) My 3588 has no 1st gear I took the cover off the top of the housing and the only thing that I could find was that the driven gear on the bottom shaft had no resistance to it. It would turn freely on the shaft. Can anyone tell me what is happening and how to fix it please Kevin

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The nut has come off the rear of the transmission counter shaft. Unfortunately it is a common problem.

To repair it you are going to have to remove the center housing. When the shaft moves forward it usually damages the front bearing and if run long enough, the housing too. The shaft may also be damaged on the front splines as the run on the bearing or in the rear as first gear damages the splines. Damage on the rear can make the gears very difficult to remove. If necessary you may have to cut the shaft through one of the spacers to remove it.

The problem arises because as the tractor is used, pressure on the gears always forces them to the bottom of the shaft. Although the movement is slight, the continual movement wears the ends of the spacers and and sides of the gears so that the nut no longer has enough torque on it to remain tight. Once the nut has loosened it wear the locking plate until it can thread itself off the end of the shaft.

Since it's introduction with the 706/806 tractors, several changes have been made to try to remedy the problem. The nut was made thicker, a hardened spacer was added to the front of the shaft, the wall thickness of the spacers was increased, and the threads were changed to left handed. None of those solutions has been entirely successful. The best solution is, once the shaft has been installed, drill a 1/8 inch hole through the nut and shaft and install a 1/8 X 1/2 roll pin. Run a safety wire through the roll pin to ensure that it stays in place. Don't worry about getting the nut really tight, it won't stop the gears from moving and can add to gear noise in the drive train since the gears will never be centered on the shaft.

It sounds like you might have a broken countershaft. The tractor would need to be split.