TN75 Hydraulic Performance Question

[TN75Jason]

I have a 2002 TN75 with cab. It had the factory joystick when I bought it with 3 remotes on the rear. I purchased the hard piping kit from the dealer to relocate the 2 remotes controlled by the joystick to below the cab for loader connections and purchased an M446 Bushog Loader. It has been working well for a while now, but the hydraulic system has a few quirks that I would like to adjust if possible. More than any other tractor I have ever owned, the joystick in a partial open position bogs the engine. Of course, most use of the joystick is a partial opening of the valve because you rarely want the cylinders to move really fast.

I have seen previous posts where RickB has given TN owners advice about adjusting the rate of drop on the 3 point htich and wondered if there was something that needed checked/adjusted to alleviate this problem. It makes loader use while moving back and forth at less than full RPM somewhat aggravating compared to a loader where most loader movement (especially downward) puts no perceptible load on the engine.

One other thing: the joystick sometimes does not return fully to center from the down (straight forward) position, resulting in the bucket drifting slowly downward when you don't intend it. Any ides would be appreciated.

Jason - Senoia, GA

 

[RickB]

There is no flow control adjustment on the remote valves. Stroking the valve spool partway will load the engine some, no getting around that. Raising engine RPM's to around 1500 will make more power to lessen the effect of the pump load on the engine.
The two remote valve sections used for loader control should be self-centering, non-detented except for the float position in the boom circuit valve being detented. Both valves should self-center from any position other than 'float'.
Check the pivots and lever at the valve itself to be sure they are not binding. Make sure the valve end of the cable sheath s anchored to the valves in a manner that holds the cable and clevis rod as straight as possible. As a last resort, you can remove the centering spring housing from the LH end of the valve section and lightly lube it.

 

[klingen]

I can't answer your question on use of the joystick bogging down the engine except to say that I experience the same thing. Both with my previous 2003 TN65 and my current 2004 TN60A.

I can say that the TN65 developed serious problems with joystick operation not returning to center both on loader raise and lower. Let me tell you! There is nothing more disconcerting than to reverse after loading the bucket and be looking behind you to see where you are going and discover that the bucket is approaching full elevation when you turn around!

The dealer made several attempts at lubrication to fix this issue, none of which worked. Finally a field technician fixed the problem by filing a pin inside the joystick that was improperly manufactured. This was a Dealer installed New Holland joystick.

 

[TN75Jason]

Thanks to both of you for the replies. I will check both the joystick and the remote ends for binding, lubrication, etc. At least I feel better knowing that the engine loading is not uncommon on these tractors.

Jason - Senoia, GA