Need help on John Deere B tranny issue

JOCCO

Well-known Member
Late style B with square 6 speed shifter. Jumps out of gear on the high side 3 5 6. Not the actual gears but the under/over shifter that allows you to go to both sides of the shift quadrant. Am wondering id its the slide or an actual gear? It is getting worse and does it when you are going down a hill not up i.e. torque load. Give me your thoughts.
 
A lot of times its a bearing that has to much play or bad, making the shaft the gears are on run off each other because of the shaft tips one way or another. Another thing is to check the shifting forks that there putting the gears together far enough.
 
I've heard all sorts of stories, bad bearings, bent shafts, worn gears, blah, blah as to cause. Have a 40 B that would not stay in range. Now have to really kick the lever to get it to move. Solution::: Take shift rails out and recontour the notch for the pawl to drop in to. I have some pix of a 44B that I redid, maybe I can post them later if you want to see the misfit. The orig notch is so shallow that the pawl does not seat and hold the fork in place. Also, be sure the springs are not broke or weak. Really the pawl should be reshaped too so as to have more round protrusion. It is hardened so would have to be ground and polished, maybe even rehardened. big expense, probably could make new part with better round for less. If you get the parts out, place the pawl in the notch and you will see how it barely sits in it. I used a hand grinder and redid the notch that way. The 40B has never slid out of gear or range and I have used it to mow around garage property for the past 10 years.
As a side note, the 40 series suffered the opposite problem, the plungers and notches were so deep as to make shifting real hard. I redid mine with ramps at the upper edge of notch and now it shifts nice, especially 1st and 3rd, never could use.
 
The bearings are worn, particularly the pocket bearing between the input shaft and the sliding gear shaft.
 
Inside the transmission you'll find that the lower drive shaft will be loose. those conical bearing and races wear and there are shims to remove to tighten them. These were generally never adjusted and they ran till they got a lot of slop. That caused the gears to run in a slight angle position and the field gears would wear with a slight angle. This would put strain on the shifting rails and the small detents. Just working on the detents is light putting an aspirin on a headache. They did retro fit the locking shifters out of the 50 series in the old B's. I never ground or messed with rails checked springs and sliders for damages. I corrected the real problems. The upper connecting bears is probably bad. Best to disassemble and do it right....lot of work.
 
I checked pix, have a before, but can't find the after. Will rummage thru data card and try to find it. Tired now, so won't be tonite, tomorrow busy with sunny day. It is a time eater to get pix posted, but thanks to James Howell I got the right magic to do it. George S.
 

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