JD 4840 powershift issue only when warm

[kx137]

No problems for first 10 minutes then after it warms up it pops out of gear and goes into neutral. I have to kill the engine, then restart it in neutral for it to go back into gear. Then it will stay in gear for and work for a little longer but the interval decreases as it gets hotter until it just wont go anymore.

A noise from the transmission sounds like fluid being transfered from one side of the transmission to the other under pressure and it doesnt do that until the problems start.

Hydraulic fluid level is good. Hour meter broke at 1500hrs id guess it has 3-4k hrs. No hydraulic drop in implement if that makes a difference.

Any help would be very much appreciated. I bought a shop manual for it but im more confused now after attempting to read it. Thanks, Brian-

 

[ctlguy]

Youre best bet is to take it to someone who can tap into the diagnostic recepticles and understands the theory of the pst trans. Most likely your hour count is higher as well as a 3-4000 hours 40 series tractor would be very very desired unit. Expect most of these bynow to have better than 8000 hours with many of them in the 10+ range. Not saying 40 series tractors don't exist with that low of hours just unlikely. Also entirely possible it has had more than hour meter installed over its lifetime. Also with any of these trans issues it can be helpfull to start with removing and replacing hydraulic filters and inspecting for iron, etc. Good luck.

 

[jd110]

Brian, the sound you are hearing is most likely the sound of clutch packs slipping. I think you need to change transmission filters and also drain transmission fluid so you can remove the sump screen to see if it is clogged. WHen it stops moving, have you tried every gear? Forward and reverse? Does the pto run? If problem persists after filter change and sump screen clean, and it will not move in any gear, then you definitely need to check some pressures to try and identify a leak or possible transmission pump worn out. It is unusual to lose every gear. usually they will continue to drive in certain gears if one clutch pack fails.

 

[RickB]

If oil, filters and a clean sump screen don't cure it, you are probably looking at a transmission overhaul which can run up to $20,000.

 

[kx137]

Thanks all for the replies. I did new filters and oil and cleaned this completely clogged sump screen then drove it around and its sooooo much better now. I can actually feel the gears engaging smoothly in the notches where as before i could barely. Heres a pic of the filter. I am just going to use this tractor for mowing with batwing and some deep plowing in some sandy loam for my motocross track. I just need a good plow now, Im excited! Thanks again everyone