Gene Sage

Member
Took tractor on tractor drive in MN. They had a dyno available so I thought I would do a horsepower check. PTO did not hold. I thought I had this SOS thing figured out but obviously I don't. I thought I had the adjustment according to the direct drive manual. With T handle all the way in the transmission light is off. After pulling it out ~ 1/4" the light comes on and stays on until you get ~ 3/8" to end of travel then light goes out. What am I doing wrong?
 
light coming on means loss of hydraulic pressure. From the fact that it only comes on when the PTO handle is partially out I would guess a leak inside the PTO control valve, most likely an o-ring that needs to be replaced. And it is probably leaking a little even when the handle is all the way out, but not enough to drop the pressure to where the light comes on (I think the light comes on qt around 4 or 5 psi and lower), but low enough to not engage the PTO clutch fully.
 

I believe it is perfectly normal for the light to illuminate during PTO engagement. I would guess your cable is not adjusted tightly enough. With the PTO engaged, adjust the cable until you can not pull it's conduit away from the transmission cover.

The lube light illuminates @ 2 psi.
 

The inside linkage for the PTO valve on those is what I would call flimsy. Mine was bent. straightening it made the PTO work very nicely.
 
Thanks for the comments guys. I checked the cable linkage per Larry's instructions and found it OK. My service manual says it is normal for lube light to be on during mid range or feathering to ease into load. It further states "the handle mid-position is the feathering point which permits P.T.O. clutch slippage by bleeding oil to sump for easing into loads". All of my operations seem normal so maybe I'm back to a bad PTO valve or feathering valve as Sean pointed to. Is there a port for checking pressure to PTO clutch pack? What goes wrong with
the PTO valve and feathering valve. I don't want to split this tractor for the third time! Everything else on the SOS works fine. I've had it in a tractor pull and gears hold good.
 

on the 4110 I took all the slack out of the pto cable with the handle out... and it ran all the time. Had to back off about 4 to 5 turns and now it works correctly. Dont know if this helps..
 
(quoted from post at 13:28:27 08/29/16)
The inside linkage for the PTO valve on those is what I would call flimsy. Mine was bent. straightening it made the PTO work very nicely.
39780.jpg


The internal linkage was bent on my 971 PTO control. Note the twisted bar in the center of the photo. After I straightened it it worked like a champ!

Scott
 
(quoted from post at 11:22:22 08/29/16)
(quoted from post at 13:28:27 08/29/16)
The inside linkage for the PTO valve on those is what I would call flimsy. Mine was bent. straightening it made the PTO work very nicely.
39780.jpg


The internal linkage was bent on my 971 PTO control. Note the twisted bar in the center of the photo. After I straightened it it worked like a champ!

Scott

Yes Scott, It was that stamped bent sheet steel cross piece that was bent n mine. It has been about two years but my recollection is that mine was made from thinner stock than yours.
 
I suppose it was about 1/8th inch, maybe a little thinner.

I thought my issue was one of a kind, but maybe we've found a common problem.

Scott
 

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