Case 930 PTO/Pump Questions

[MotoExpedition]

Need some help as I'm trying to help a friend with his 60s 930. I was told the hydraulic pump doesn't work...it is the type with the pump below the PTO.

Upon opening, I noticed the pump shaft driven by the sprocket/chain is free spinning from the sprocket. Is this normal? Best I can figure is either a woodruff key has sheared or it uses a hydraulic coupler and thus is normal. So in the image, yellow spocket spins free from red shaft...shouldn't these be locked together?

Another question. I removed the PTO so as to remove the chain but the PTO clutch basket (Green arrow) is stuck on the shaft despite removing the snap-ring. What's the trick?





 

[casecollectorsc]

Isn't the shaft just a idler shaft and the sprocket is turned by the pto? Was the coupler that fits in the slot and a slot in the pump in place?
 

[jon f mn]

The gear with the yellow and red is an idler and is turned by the chain. If the bearings and chain are good there is nothing wrong. There is a coupler that goes between the pump and shaft at the red arrow, it is a disc with a flat that fits in the slot on the shaft and another on the other side for the pump. It's likely down in the housing. I can't help on the pto parts, but question why you want it out? If that part is still hooked to the front and is turned by the engine, everything is good. If not you need to split the tractor to pull the snapring on the front of that shaft so the shaft comes out the rear. I'm not sure if that basket comes off the shaft from the rear or not.
 

[MotoExpedition]

The coupler that fits in the slot was in there...yes it did fall down into the casing but only when I removed the pump...I heard something fall and it was the only thing down there.

The yellow sprocket/red shaft obviously drives the pump, given the coupler that fell joins it to the pump's driven shaft. And the yellow sprocket gets its power from the PTO gear via the chain.

The issue is the shaft where the coupler disc goes (red arrow) spins freely from the sprocket (yellow arrow) so I don't understand how it is spinning the pump if the yellow sprocket spins freely from the red shaft...essentially, the pump shaft is being rotated by the Red Arrow shaft through the coupler which obviously gets its rotation from the chain and yellow sprocket but when I immobilise the chain/sprocket, i can freely spin the Red Arrow shaft...meaning if the engine were running and the chain spinning the yellow sprocket, I'd be able to hold the Red Arrow shaft and stop it rotating...so clearly it cant spin the hydraulic pump shaft.

The reason I want to remove the basket is it's the only way to remove the chain and what yellow/red sprocket/shaft.

The red shaft doesn't use a bearing; it has an oil-impregnated brass bushing.

It just doesn't make sense to me.
 

[casecollectorsc]

Did you look for a mender link in the chain?? Two of us told you how this assembly works.
 

[DKase]

Is your lower sprocket broke loose from the hub on the lower shaft? There is a connecter link in the chain that can be removed to get the chain out. Removing the PTO gets you no where.
 

[MotoExpedition]

After a reply from my Case dealer in Rochester, I realised i'm not being as clear as I should.

I'm going to change my wording.

In the altered photo here,

-The blue arrow is the 'shaft'.(It is pressed into the housing and doesn't rotate...it is static)
-The yellow arrow is the small 'sprocket'. (It spins by the chain)
-The red arrow is the 'DRIVESHAFT'. (This is driven by the sprocket and sloted on the end where the coupler 'key' goes to lock it to the pump's driven shaft)

THE DRIVESHAFT AND SPROCKET SPIN ABOUT THE SHAFT.


My problem is the DRIVESHAFT spins idependently from the sprocket. So if i spin the small sprocket, I can grab the DRIVESHAFT and stop it spinning...whilst the sprocket continues to spin! THE DRIVESHAFT IS NOT ATTACHED TO THE SMALL SPROCKET.

This doesn't seem normal to me as it is the driveshaft that spins the pump's 'driven' shaft. The chain should spin the sprocket which should spin the driveshaft which should spin the pump's shaft.

So I'm thinking either a woodruff key that locks the driveshaft to the small sprocket has sheared, or there is a viscous coupler or kind of torque converter that, with enough RPM locks the driveshaft to the sprocket.

The latter being ultra unlikely given the age and simplicity of the rest of the tractor.



 

[DKase]

Find the connecter, remove the chain, pull the lower sprocket and drive hub off the lower shaft, and you will see the problem. The yellow sprocket should be attached to the red hub.
 

[MotoExpedition]

Great...thanks very much for confirming that!! Do you know if it uses a woodruff key? Think I weld the sprocket to the hub if I find a destroyed woodruff key slot?

Also, do you mean the chain uses a 'master link' that would allow me to split the chain?

Thanks again!!
 

[MotoExpedition]

Sorry for some reason these replies aren't in chronological order...so i missed this.

Got it now, thanks
 

[jon f mn]

That gear will likely be welded on and is now broken. I've never had one apart, but there doesn't look like any kind of hub on it that can have a key in it. You may be able to weld it back on, butbive never heard of a failure there so used parts should be fairly easy to come by.