Yanmar YM336D Popping out of 4th gear on Powershift

[jsdepottey]

Is there something to inspect or adjust that will stop the tractor from popping out of gear when trying to use the 4th gear range? It does not do this in range gears 1-3. It seems like its not fully shifting into 4th. I can use 1st gear on the powershift with keeping slight pressure on the range shifter. When trying to use third its really trying to kick it out of gear. Any help or suggestions would be greatly appreciated.

Jim

 

[Gjamtrac]

Most likely you need to shim the shift shaft. All the ones I have seen have a loose shaft that partly slides with the shift fork. Put some shims over the end of the shaft so it can't slide, allowing the fork to fully engage in the detent.

 

[jsdepottey]

Thanks for the quick response. Can you remove the range shift lever from the top and put the shims in from there? I saw springs and ball bearings and got scared! Can you walk me through where the shims go? I really appreciate the help.

 

[Car Doc]

Excessive play in the shift tower (ball,bushing,pin,shift shafts if applicable etc) can cause short throw also a bent lower shifter section under the pin (unlikely) could also. If there is up and down or twisting movement in the shift handle that would be my first place to check. It could be more serious but the shift tower assembly is my guess. hth

 

[jsdepottey]

Excessive play in the shift tower (ball,bushing,pin,shift shafts if applicable etc) can cause short throw also a bent lower shifter section under the pin (unlikely) could also. If there is up and down or twisting movement in the shift handle that would be my first place to check. It could be more serious but the shift tower assembly is my guess. hth

Thanks for the advice. I will check the up/down and twist free play when I get home. Can I open the cover where the shift range shaft connects and inspect there without letting springs and ball bearings loose?

 

[Car Doc]

I believe you can. I have a similar transmission and never had the top off but the 4 little bolts at the base of the shifter handle would be where I would start make sure its in neutral to simplify re installation. I just checked mine and I have absolutely no up/down/twist in mine and it works ok.

So just a heads up if yours is tight also you may have to go a bit deeper and take the cover off under the shifter which I cant advise you on that (at this moment anyway) because of the creep lever. I have no idea w/o researching it how it engages its shift fork etc down below so proceed with caution there. Should be no big deal but knowing something before hand is way better than learning after there is a question.

 

[grainger12002]

does the low gear lock out have any effect on 4th gear ? mine will act as the one described,but not always and it just feels like it not going in all the way,all the othrers are a nice easy shift,not loose or worn at all

 

[jsdepottey]

does the low gear lock out have any effect on 4th gear ? mine will act as the one described,but not always and it just feels like it not going in all the way,all the othrers are a nice easy shift,not loose or worn at all

Not sure what the low gear lock out is, I just got the tractor. Is that the little rotating knob at the back of the shift assembly? I can't get mine to rotate. The shift is definitely not smooth and easy all the time. Sometimes I need to shift into other ranges before I can select the one I want.

Car Doc, I do have play up/down and twist. Looks simple enough to take the cover off but then what?

Gjamtrac, what part do you add shims to?

Thanks again for the help.

 

[Car Doc]

Car Doc, I do have play up/down and twist. Looks simple enough to take the cover off but then what?

Gjamtrac, what part do you add shims to?

Thanks again for the help.

Replacement or repair of worn parts at that point. How much play depends on how bad the shifter throw is affected thats the part I can not advise you on from here. But studying the geometry of the mechanism should explain my train of thought on the problem I hope.

I am curious about the shifter shaft shimming procedure also he apparently has seen this so I may be way off in left field?

 

[Gjamtrac]

The ends of the shift shaft are smaller than the rest of the shaft, put 1/4" or 5/16" I.D. shims onto the rear end of the shaft to push the shaft forward, or you can use thin flat washers.