Jd 7800 powershift. Rough shifting

[dude91]

Have a JD 7800 powershift. Shifts hard going into 16th gear when transmission is warm. Any quick fixes like heavier weight hydraulic oil?

 

[used red MN]

Changing the oil viscosity is not the answer. The recommended fluids for that transmission will all be nearly the same viscosity, fluids outside of the factory specifications will have a good chance of damaging the transmission. However, making sure the fluid has been changed and new filters have been installed is a good starting point to address the problem. There is a transmission shift calibration sequence for that transmission that may help your problem. I believe it can be found in the owners manual but I am not 100% certain. It may only be in the technical service manual for the tractor.

 

[buickanddeere]

Have a JD 7800 powershift. Shifts hard going into 16th gear when transmission is warm. Any quick fixes like heavier weight hydraulic oil?

What brand of oil is in the transmission , how old is the oil and any water contamination ? How many hours on the tractor ?

Is there a clutch pack worn out and is now metal to metal ?

 

[dude91]

What brand of oil is in the transmission , how old is the oil and any water contamination ? How many hours on the tractor ?

Is there a clutch pack worn out and is now metal to metal ?

9400 hours on tractor. Oil and filters have been changed, all JD. Probably, filters could be changed again. Clutch is really jumpy. Shifts fine when its the first shift of the day.
Thanks for responding.

 

[EX Deere Farmer]

Have a JD 7800 powershift. Shifts hard going into 16th gear when transmission is warm. Any quick fixes like heavier weight hydraulic oil?

You need to calibrate the the transmission. It is not that hard to do but you will need to get the step by step instructions to do it correctly. You will need a jumper hose for the SCVs to warm up the hydraulic oil this time of year. Also covering the radiator with cardboard helps too. Do not skip getting the hydraulic oil warm enough or you will make the problem worse. DO not change the oil to a thicker oil!!! This is a controller problem, do not turn it into a mechanical one.
Also you did not say what year your 7800 is. The later models had transmission updates that made them shift better. Also the 15-16 shift is hard in those tractors as there are two clutch packs shifting at that time. It is actually hesitating the shift. Also something that will help the shift be smoother, you can kind of trick the controller, just put your toe on the clutch pedal and hold it down just an inch or so. The controller "thinks" your going to stop and changes the shift timing. This usually helps.
Thing to remember is the 19 sp. PS is one of the first JD had that has a computer involved in the shifting. The hard shifting issues where most designed out in the ten series.
P.S. Change the hydraulic/transmission filters before doing anything. You do not want to damage the clutch packs. The last rebuild I was involved in on one of these ran into around $9K in parts a lone.

 

[dude91]

Thanks for info

 

[Kollebo]

Hello
Did you find the problem
Mine is exactly the same
Gear 15-16 is very rough
Also 12-11 when downshift.