JD 6410 1 2 3 work fine 4th is slipping in partial power shift??

[Zebrafive]

Tried to get error codes I think there are none, although my display is not working perfect either, did buy a repair manual on cd but it has no diagnostic section of course, that is a different manual I will try and get one of those and keep you posted. The way it looks 1 2 3 go through the planetary and 4th is direct drive or engine rpm so I don't know what the problem is.

Which manual did you get? TM4572 or TM4574?
Although 4th gear is direct drive it is achieved by locking together the second and third gear sun pinion gears. So there is a 4th gear clutch in the Power Quad transmission.
The Power Quad has a built in oil pump. If 1st, 2nd and 3rd work OK, I think the pump is OK, but there is a port to check it's pressure. The engagement pressure should be 170psi.
There are also shift valves and the valve(s) could be not fully shifting or leaking.

 

[fatdaddyfarmer]

Which manual did you get? TM4572 or TM4574?
Although 4th gear is direct drive it is achieved by locking together the second and third gear sun pinion gears. So there is a 4th gear clutch in the Power Quad transmission.
The Power Quad has a built in oil pump. If 1st, 2nd and 3rd work OK, I think the pump is OK, but there is a port to check it's pressure. The engagement pressure should be 170psi.
There are also shift valves and the valve(s) could be not fully shifting or leaking.

I now have both of the manuals, the engagement pressure is 170 so the pump is fine. when I shift from 3rd to 4th it pulls some but able to stop the tractor with the brakes, also when the tractor is in 4th it does not speed up, it moves at 3rd gear speed. also can the shift valves be removed without removing the transmission or can you remove the shift valve housing and then pull out the shift valves?

Thanks for all the help ,Randy

 

[Zebrafive]

Not sure if valves can be removed without removing the shift valve housing. It's on the bottom of the trans. In TM4574 see page 55-10-7 it shows the shift valve housing. page 55-10-23 has removal instructions. Page 55-10-26 show the valves. Key D B3-C4 shift valve is for 3rd to 4th gear shift and the one that might be sticking. If it's Ok then it might be the clutch pack.

 

[fatdaddyfarmer]

Ya I looked at tractor pretty sure valve housing will have to be removed to get out shift valve. workin on second crop hay now when I get some time I'll pull housing hopefully shift valve is the problem, not sure if I could handle clutch pack myself.

 

[bigblock]

I was thinking clutch when I read the title. Clutch slipping problems usually start showing symptoms in high gear.

 

[Zebrafive]

If not a shifting valve problem, I think it's the fourth gear clutch pack, not the main clutch.

 

[fatdaddyfarmer]

Finally removed shift valve housing, did not find any problem there, everything looked good. Probably a clutch pack.