Chinese Tractor Owners Association

I was using the Jinma loader the other day and bent the bucket cylinder
rods. Both of them; one really badly (45ï½° bend) and the other not as
bad but still bad. I had to use the press to straighten them and that
screwed up the chrome on the rods, of course. They should be replaced,
but I'm using them so far. They aren't leaking yet, but they surely
will. I have absolutely NO idea why they bent that way – I wasn't doing
anything but moving some loose dirt when my bucket curl started making a
horrible groaning noise (relief valve, probably) and my brother noticed
the rods were pretzled.

My main problem is, OEM replacements are $400 each – ouch! And that's
before I ship them to the Virgin Islands. I'd like to use after-market
cylinders that could be had for considerably less than half that, but
there are none I can find available in the same configuration. The OEM
cylinders are 2" and about 34" long, but only have about a 22" rod in
them. So, here's the question:

Is there any reason I couldn't use standard 2"x24" cylinders and
relocate the top cylinder mounting points to part way down the arms?
Such cylinders can be had for about $150 each and the relocation work
wouldn't take more than half a day. A few hose ends or adapters and I'd
be good to go, I think.

What say those of you who know way more than I do about such things?

I looked at that some Bob, and it looks to me as though it should be no change.  The OEM setup has the cylinder operating basically parallel to the loader arms, though at the very end of the dump stroke they actually cause the rods to flex when the hit the arms.  Going to the shorter cylinders would actually eliminate the end-of-stroke flexing, I think, as the closer attachment point would allow the rods to just clear the arm ends at full extension.  Even if not, I could raise the attachment point a half inch ad achieve the clearance that way.

My objective on the new mounts would be to avoid the flexing in the old arrangement and also to use the cylinder stop to limit the bucket travel on extension.  The OEM setup, using shortened rods (well, actually extended cylinders and a short rod) looks to have been done that way to put the attachment point at the "bend" in the arms and use the gusset plate as the attachment point.  The OEM cylinders actually have a couple inches more travel than needed, so they try to force the bucket on full extension, flexing the rods over the end of the arms.   By making a new attachment plate part way down the arms I could set it so that the curl cylinders were at full extension when the bucket was at full dump, thus using the cylinder stops to prevent the rods from flexing over the end of the arms.  I think.

If I use attachment plates that are sufficiently wide, I don't see any issues of excessively concentrating forces in the middle of the loader arms.  The geometry of the bucket curl shouldn't be changed and it should function as before, minus the tendency to flex the rods at full extension.  Again, I think.  I'm not an engineer, obviously, just a poor broke-down old blacksmith with a thin wallet.

Email coming your way, Tommy, thanks!

Rich

Post edited 8:43 am – October 19, 2011 by RichWaugh

Moot point, David.  Tommy has gotten me fixed up and I'll be replacing them with new OEM cylinders. The other issue is that there are no hydraulic shops in the Virgin Islands and it isn't cost effective to ship the damaged cylinders out to have them re-manufactured.

I'll be doing a bunch of mod work to the loader bucket mounts and cylinder mounts to correct a geometry issue that causes the cylinder rods to flex over the loader arms at full uncurl.

That's a two-part question.  First answer is, no.  Second answer is, Hell no!  If I diversify any more I'll have to clone myself – again.