Sea Foam Trans Tune In Power Shift

I was wondering if anyone has ever used this in a Power shift tractor to help with symptoms of sticking valves in the valve body. The tractor in quesiton is an Allis Chalmers 7000. It lags between shifts from 2nd to 3rd (it has the 3spd powershift) when warm. When cold, the thing shifts fine. It never slips, it just slams pretty hard and if you have the right load on the back, may pop the front wheels off the ground (I let off the throttle when I shift it any more so it doesn"t slam into gear). So, I don"t think it"s the powershift clutches of seals, as it still holds great pressure. I"ve put a pressure gauage on it before and when I shift it, the pressure just drops and comes right back up, but it just stays really low for a split second longer on the 2nd-3rd shift than the 1st 2nd. I am thinking it is a sticking modulator valve or possibly a worn mechnaism in the shifter not pushing the detent all the way into the gear. But before taking apart the valve body, I wanted to try this if it is safe. It has fluid and filter with less than 40 hours on it. Fresh change didn"t really help much. It also likes to kick the PTO out of gear when you shift the powershift when hot and nothing has been shifted for a while, because the PTO relies on constant hydraulic pressure to hold it engaged for safety reasons (so when tractor shuts off, PTO autimatically disengages).

Hurst

I'm not familiar with Allis's... but I think you have a pressure/flow problem rather than a valve problem.
I'd start by checking/cleaning the pickup strainer for the pump that supplies the powershift. Beyond that I'd say you have the makings of a leak. It's just starting so the pump can sort of, almost keep ahead of it yet. Once it gets worse the pump won't keep ahead of the leak anymore. Then you'll see a constant pressure loss on that clutch. I would think that if only one clutch is so far affected, that would be the offender rather than the pump UNLESS there are several different size clutch drums with different fill times/displacements.

Rod

The powershift runs off the main pump, it just has a big flow divider in it, but the part divided to the power steering also goes to the powershift, and the powersteering is fine. Also, it has been the exact same way for the past 4 years I have owned the tractor, just got a fresh fluid and filter change, which also included cleaning the strainer, and nothing changes. If I shift back to 2nd, then to 3rd pretty quickly (in neutral or a low gear... not road gear) it shifts what I would think is normally. The thing is the pressure just dropps off in that circuit when I shift and leaves the whole transmission hanging with no pressure for a split second, then all of a sudden it gets pressure back and works. That's why I was thinking it was a sticking valve, because that is what I saw when I hooked a pressure gauge to the powershift test port. It's not a lack of flow, because then if I cut the wheel very quickly (remember, steering is on the same circuit), the pressure remains constant in any gear range, PTO engaged or disengaged. My guess was a hanging 3rd gear spool, modulating spool, or pressure control spool. I'm not completely ruling out faulty seals in the powershift, but it just doesn't seam likely enough for me to not try something else first, like running a cleaning agent in the transmission to try to clean any gunk out of the powershift valve body.

Hurst