Komatsu D31P-20 Shifting Trouble

[southernman13]

I have a D31P-20 LGP, Runs perfect in every way except for shifting. All three speeds work fine but when it warms up it doesnt want to shift back to first gear or low. it will go from medium to high but acts like its binding when you try and go back to low. the lever doesnt want to move all the way back. I looked at all of the linkage and it seems fine. let it cool down and it goes right back into low. when I say it warms up, there isnt any indication of it getting hot. The temp guage is in the middle and i know the guage works because it was getting close to the red and I replaced the thermostat and it cooled right down. There isnt a trans temp but looks like a light for that function. All of the idiot lights come on when you trun on the key and go out once started so they appear to be working. Has any one had this problem or heard of it. Thanks

 

[southernman13]

D31p-20lgp

Am I the only one ever having had this problem? I noticed last weekend it did it even when cold. but more frequent when warm

 

[Alvin Tim]

I have had a similar problem on a D41 but mine was shifting hard all the time and I ended up replaceing both cables. I could not believe the difference between the old and new cables. The cables did not appear to be in bad shape and after removal they didn't seem to operate very hard but must have had enough binding to cause them to operate hard.

 

[southernman13]

D31-p

Thanks, I dont remember seeingany cables when I looked at it. seemed to be linkage. but I could be wrong, Its a 1996 but it makes sense and does feel like a cable hangin up, thanks again, other than that its a great little machine

 

[trackfanatic]

There are a couple of control valves on top of the transmission. Chances are the O rings are gone. Cost me $380 to find that out. $0.04 for the 2 O rings and the balance to get a serviceman to come figure out what was wrong.

 

[southernman13]

D31

Thanks for the info, I'll check it out next time im on it.

 

[willie59]

southernman13, if you have linkage controls that go from drive lever down to tranny valves, you need to check all your linkage pivots. Wherever there is a linkage pivot point, like a bellcrank, Cat and Komatsu both put seals where the shaft goes through the bellcrank mounting. Over time, the grease dries out that lubes the needle bearing and the bellcrank becomes stiff to operate. And with seals on the shafts, no amount of spay lube will loosen them up, you have to take the assembly apart, clean it up, and if the needle bearing is still good, lube it up and re-assemble. I've seen this on a number of Cat and Komatsu machines.

 

[southernman13]

D31

Thanks for the info, that all makes sense from what I remember seeing. I'm sure you are right on. Thanks again and have a great day.