Save my Lawn Tractor's Rockshaft Cylinder

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SteveHGraham
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Save my Lawn Tractor's Rockshaft Cylinder

Post by SteveHGraham »

Wondering if the forum geniuses can save me some cash.

I have a John Deere 430 garden tractor. This is not a Home Depot toy. It's a 1992 Yanmar with real hydraulics. It's worth working on.

It has a hydraulic leak. I had someone operate the deck lift while I watched, and oil is shooting out of what is known as the rockshaft cylinder. This is a short hydraulic cylinder under the mower's left rear fender. I found a service manual online, figuring it would tell me how to remove the cylinder so I could replace the seals. The manual says to replace the entire cylinder.

I'm a little amazed at that advice, obviously. I can get a new cylinder for around $180, but I have to wonder...is it really possible that John Deere would sell a hydraulic cylinder that can't be repaired? If so, is there a source out there that would have a generic cylinder that would fit?
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LIALLEGHENY
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Re: Save my Lawn Tractor's Rockshaft Cylinder

Post by LIALLEGHENY »

Yes I could see John Deere doing this. Makes it a proprietary part ,that you can only get from them. Does the cylinder have an end cap that can be unscrewed, or pinned or is the cylinder completely welded? Is the rod threaded on the end or is it welded?
You could try Bailey hydraulics for a cylinder, Hercules Sealing Products , Ebay, Surplus Center, and I'm sure there are other places for cylinders as well. Depending on how the cylinder is constructed (welded?)you could cut the back end off the cylinder, depending if the rod end comes off( cut that off as well). Then figure out what seals you need and weld it back together again. I've had to do this several times over the years. Hercules is a good source for the parts.

Nyle
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liveaboard
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Re: Save my Lawn Tractor's Rockshaft Cylinder

Post by liveaboard »

I agree with Liallegheny;
It probably comes apart in some diabolical way. I had one the appeared to be a smooth cylinder, the top was screwed on and it was painted. A vice and a pipe wrench opened it up.
I've cut and shortened a large cylinder; it's not difficult.
seals are available. Sometimes the top dust scrubber is not available, but for us lathe owning people, they're easily made from nylon.
John Hasler
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Re: Save my Lawn Tractor's Rockshaft Cylinder

Post by John Hasler »

Nyle writes:
Yes I could see John Deere doing this. Makes it a proprietary part ,that you can only get from them.

They do this. They also buy standard parts such as bearings and have them marked only with the JD part number. Fortunately there are cross-references, at least for bearings.

John Deere would also sell a cylinder that can be repaired and then tell you to replace it. Take the cylinder to a hydraulics shop.


On big farm tractors they do something even uglier. All major components contain electronics and are on a CAN bus so they use encrypted handshakes to prevent none-JD components from working.
b4autodark
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Re: Save my Lawn Tractor's Rockshaft Cylinder

Post by b4autodark »

www.jdeereparts.com $169.00 new. There is a used on on Evilbay for $80.00.
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warmstrong1955
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Re: Save my Lawn Tractor's Rockshaft Cylinder

Post by warmstrong1955 »

We used a lot of John Deere Utility Tractors for transportation & nipping in the mines. (Models like the 4500, or 4700 etc) The small cylinders, like the steering cylinder, were non-rebuildable. They were welded together. Same goes for things like a 3-point hitch cyl.
They leak....you toss 'em.
I would guess your cylinder is the same design.

I did carve a few apart on the lathe, to see if I could reseal and reweld them, but they had more problems than just a failed seal, and were not worth the effort or the parts. Lot of that has to do with the environment, so it may be worth a try for yours.

Bill

What they look like new & shiny.....
4510 Henderson.JPG
4510.JPG
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SteveHGraham
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Re: Save my Lawn Tractor's Rockshaft Cylinder

Post by SteveHGraham »

Thanks for all the replies.

I was looking at this problem online last night, and suddenly I remembered that I was not poor, so I ordered a new cylinder. I didn't want to give John Deere the satisfaction of selling me a new part made so it was deliberately hard to rebuild, but I got over it.

My plan is to install the new one and keep the old one. It may be that when my machine tools are working again, I will be able to fix it, and then I'll have a spare. Alternatively, I can open it up and learn things about it, and maybe next time, I'll be able to take a generic cylinder and adapt it. Then I'll send John Deere a childish email.

I assume the part is made by Yanmar, since they made the engine and possibly the whole tractor. Maybe not.
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warmstrong1955
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Re: Save my Lawn Tractor's Rockshaft Cylinder

Post by warmstrong1955 »

Engine is Yanmar. Hydrostatic trans is Sunstrand. The iron, is genuine John Deere.
I would guess your cylinder is also John Deere, but I don’t know that. The JD small cylinders I am familiar with were all made in the US.


http://www.tractordata.com/lawn-tractor ... e-430.html
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rrnut-2
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Re: Save my Lawn Tractor's Rockshaft Cylinder

Post by rrnut-2 »

If it was that age Yanmar, getting parts would be near impossible. I know, I had one, 'a 76. It was a good tractor but 2wd, but getting parts was a nightmare. Sold it and bought a John Deere 4200, and this time 4 wheel drive.

Some of the real small cylinders on this tractor are all welded together, like the mower lift cylinder and the snow blower lift cylinder. All of the loader cylinders are repairable. The best place that I have for pricing on parts has been Bombergers in PA. The dealers around here in NH seem to think that the parts are gold.

Jim B
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SteveHGraham
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Re: Save my Lawn Tractor's Rockshaft Cylinder

Post by SteveHGraham »

rrnut-2 wrote: Mon May 20, 2019 10:30 amThe best place that I have for pricing on parts has been Bombergers in PA. The dealers around here in NH seem to think that the parts are gold.

Jim B
The first price I saw for this cylinder was $408.00. Reminds me of the time I priced a Harley (actually Japanese) carb gasket at a dealership. I went online later...same part for 1/3 the price.

But yeah, we should hate the Asians for selling us things at better prices!

We bring all this stuff on ourselves. I have zero pity.
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SteveHGraham
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Re: Save my Lawn Tractor's Rockshaft Cylinder

Post by SteveHGraham »

My cylinder arrived. The ends are WELDED on. Nice way to force customers to buy new ones.

I"m wondering how hard it would be to make one from a Surplus Center cylinder.

Here's a question: am I supposed to put fluid in this thing as best I can before installing it? It's full of air right now.
Every hard-fried egg began life sunny-side up.
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warmstrong1955
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Re: Save my Lawn Tractor's Rockshaft Cylinder

Post by warmstrong1955 »

The only cylinders I bench prime, are master & clutch cylinders.
For any others, Install it, then cycle it slowly full stroke several times, and keep an eye on the oil level.

Bill
Today's solutions are tomorrow's problems.
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