gear selector JD 3010

what is the sequence to adjust the turnbuckles on the gear selector that is on the dash.
put new gears into this JD 3010 and now it shifts real hard trying to adjust the turnbuckles but it's not working out to good.
any helpfull information would be appreciated

First remove the dash cowling. This is the short piece behind the hood, just four bolts. This way you can inspect the shifter drums. They should be free to move but still tight. Too much free play will make them not work correctly. There are bushings on the shifter and the drums both. Also make sure the pivot bolt is tight. They come loose and allow the drums to separate and the drum latch will not function correctly then. It will slip between the drums rather than locking one or the other drums. The latch should lock one or the other drums. Not allowing them both to move.

The drum latch that the gear shift lever works back and forth, is held in the shifter lever casting with a pin. This locks one drum while the other does the shift. The left drum is park and four speed ranges. The right drum shifts low range/forward, high range/middle,and reverse/back. Make sure this latch is working freely. Also check the corners of the latch they get rounded off. Look at the slots in the drums. They should be square. Some wear will work,too much will let the drum move too much and make the transmission shift hard/grind. If all of this checks out okay then you are ready to adjust the shift linkage.

Block the tractor from rolling. Then move the shift lever out of park into the first speed range. You can feel the shift detent. Then adjust the range linkage so the latch pawl lines up with the first slot in the left drum. So that when you move the lever to the right into the hi/lo/rev drum the latch locks the speed range drum in place. When you have that done then adjust the hi/lo/rev linkage so that the slot in the right drum is lined up straight across from the latch.

This way when you pull the lever back into the first range the shifter is lined up to go into the hi/lo/rev drum.

You stated that you replaced some gears in the transmission. Did you rebuild the hi/lo/rev synchronizers and collars??? Also did you replace the detent springs?? They are behind two plugs in the right side of the transmission. I always check the detent springs, detent plungers and shifter quadrants when I have the gears out of the transmission. These tractors are getting old enough that many have the detent tapers in the back of th shift quadrant worn out. Then they will shift hard/grind. Also the detent plungers can have the tapered nose worn so they don't hold the shifter quadrant correctly.

If you have done all of this and it still shifts hard then remove the floor panel and the top transmission cover. Then shift the transmission. You should be able to see what is causing the shifter to work hard. Hard shifting is usually bad synchronizers and collars. They get burrs worn on them and will not shift correctly. Grinding is usually bad synchronizer clutch plates/separators.

Let us know what you have done and what you try.