Scratching my head 430 Rock shaft cylinder

chuck machinist · Aug 9, 2019

I remove the rock shaft cylinder housing from the 430 today. I found the piston seized in the boar, and with great effort, it fought me all the way to the end before coming out. Cylinder bore is near perfect, no scarring or scoring. I?m puzzled that it took that much effort to move to the end of the cylinder almost 4 inches of travel, again it? fought me the whole wayCM

tomturkey · Aug 9, 2019

Funny thing about old tractor fever, it seems to be a fight to get most things repaired/fixed but we enjoy the work. If you were working on a car, you might just throw in the towel and take it to a real mechanic. At least that's how I feel about tractor and car mechanicing. As far as why did the piston fight you, maybe the wrong o-ring. It may have been trying to roll as you pulled?? could be gobble

r.w.b. · Aug 9, 2019

I had 1 too snug,i fixed a heavy clamp to stop it from flying out.applied 150 psi air to the oil inlet .it hit the clamp i made pow.i let air off and it came out just fine the rest of the way

chuck machinist · Aug 9, 2019

The Cap came off nicely when I applied air pressure to the oil inlet, but the piston proved to be quite difficult .A block of wood and a 10 pound hammer would not move it. I micked the bore and piston and had .002 Clearance. The wiper ring disintegrated once I placed the piston on the shop bench. The seal ring appears to have hardened, as it should be soft and pliable . I suspect moisture contamination. CM

jon f mn · Aug 9, 2019

The hard part is done! Those arms must not have been too bad to get off.

chuck machinist · Aug 9, 2019

I rested my arm on one after I removed the cover ,and it slipped right off!CM

kevinthefixer · Aug 9, 2019

Chuck, doesn't .002 strike you as a bit tight? I'd have thought 3 or 4 would be about right? But my guess is you were fighting the hard seal ring. When I did mine on my 611b the original seal ring was nothing but crumbs, the wiper probably held more pressure than it did. My bore had a few scores but I called it good enough and haven't had any problems. I think you're off on the water damage, though, if that was the case I'd expect rust in the bore, so I think the hard seal was just old age and possibly incorrect fluids used. I know that was the case with mine. The new seal (courtesy John Saeli) was a bit of a bear to get on, I used the hottest soapy water I could stand and still had it turn on me when it finally fell in the groove. It's tough, though, I managed to straighten it out with a flat-blade screwdriver and didn't knick it. I used a 220-grit cylinder hone on the bore, looked only a bit rougher than I'd hoped and as I say it works well now.

mEl · Aug 10, 2019

A quick note on oils, back here in Pa. we had an oil company that was selling a Hytran replacement to a few of our backhoe customers. After some hours the cylinder packings would swell so tight that they literally squealed when activated, at repair time we actually had to pull the rods out of the barrels with our winch on our big rollback pickup and delivery truck.

flatpkr · Aug 10, 2019

A couple months ago I pulled the piston and replaced the rock shaft seals on a Case 430, which is probably the same as your tractor. I removed the pipe plug at the end of the cylinder and tapped out the piston with a wooden dowel rod inserted in pipe plug hole. Came out fairly easy.
Jim

chuck machinist · Aug 11, 2019

Having had a conversation with the previous owner mel , I agree with your observations. Thanks for all your thoughts on this issue fellows. CM

Scratching my head 430 Rock shaft cylinder

chuck machinist

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tomturkey

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r.w.b.

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chuck machinist

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jon f mn

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chuck machinist

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kevinthefixer

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mEl

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flatpkr

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chuck machinist

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