3 Point drop rate on JD 40 T

[TractorNutt]

I have a 40T that drops the 3 point load very fast. Is there an adjustment to reduce the drop speed. It has the Dual Touch-O-Matic. Can't find it in the service manual. Any help is appreciated.

 

[tstex]

T-nutt,

If you slowly move the control arm from having the lifts in the upper position to the lowest position, what happens?

do you know the history of how the hydraulics and how they worked before? did it just start doing this?

Have you changed the oil lately or checked to see the level?

Post back and we will get this identified,
tstex

 

[TractorNutt]

It drops very fast at one point toward the rear of the lever travel. It is nearly impossible to move the lever back slow enough to get a slow load drop. I have a fairly heavy 6 foot JD672 finish mower on the 3 point. I just bought the little 40 and do not have any past history with it. The key was sheared in the pump and fixed that but found no cause for it shearing. I have a JD750 utility tractor and it has a valve to turn to adjust the rate of drop depending on the weight of the load.

I have been trying to also repair the seals in the rockshaft so the fluid has been changed a couple times putting in seals, etc. The system always appears to be very clean.

My other problem is that it wants to cycle up and down. It is like it leaks down and then senses it and picks to load back up again. I have lapped the check valves on each side and they really look very good. But that didn't help. They are the older single stage check valves.

I have fixed everything else on the tractor and it is great but these hydraulics have me busy. I have all new seals on order from JD for the pistons, crossover valves and the heads. Trying these new seals was my next step in trying to remedy the drop and the cycling.

Any ideas are appreciated.

 

[tstex]

Here are a couple of comments you made and questions:

"It is nearly impossible to move the lever back slow enough to get a slow load drop." Why? If you move the control lever from the up position to the down position, why will the control knob not move slowly? Even if you move it slowly, do the lift arms on the 3-pt still move fast? what happens if you have something on it about 300lbs...do you get the same results?

"I have a fairly heavy 6 foot JD672 finish mower on the 3 point" How much is "fairly heavy?" I think the weight limit on the back of these TOM's are about 800-900lbs.

The model M/MT/40 series are good utility tractors and are work horses, but with the implements made for them...if you use something larger than it was spec'ed for, it can/will bog it down.

Let us know,
tstex

 

[TractorNutt]

When I move the control lever to the rear in about a 1/16th of a inch to the rear the load will move from zero to a slam down.

I would guess the JD672 weighs close to 500lb. I will experiment with a lighter load after the 4th of July. Going out of town...will let ya know. Thanks,. TNutt