None of the 2 answered me if that's why they don't engage the gears and I already solved the problem. If that was why the low gears did not enter because the bushing of the change rod was damaged, it had a lot of play and instead of changing those gears, the rod moved in the rubber where the plastic bushing is inserted. yes, let the rod roll and move back and forth. With what I put it does the same job (by putting 1 piece of plastic tube with the appropriate internal and external diameters) that moves and rotates along with the rod inside the rubber of the bushing and greased