broken lift arm shaft

[jinman]

Absolutely, that's why in absense of having a written factory directions, one need to have proper witness mark on all compaonents, Rock shaft and lift arm externally and what that translate to position of arm inside. This can be done with lift arm fully up or down, no matter, but much easier with the arms down and in rest.

JC,

The repair manual instructions say to mark/score the rockshaft and lift arms for re-alignment when reinstalling. It also says to do the same with the internal lift lever. However, that is for reinstalling the same parts. If I buy a new rockshaft and it is not keyed in any way (and certainly won't be marked), it would seem that the only important thing is the relative positions of the inside lever and outer arms. After installation of the rockshaft, but before putting on the lift arms, I could run the lift control all the way to the top and then put the lift arms on the shaft ends and also put the lift high-limit lever on at that same position. The lift all the way to the top and the lift arms also at the top seems a constant in every case I can think of. Here is a photo of the right side rockshaft on my tractor (not that it looks any different from the OP's).

Edit: I'm adding one more photo. Wouldn't it be cool if you could remove the toplink bracket on the rear of the lift casing and have an opening into the case to view and hold parts? (You can't) Check out my added photo.

 

[JC-jetro]

The repair manual instructions say to mark/score the rockshaft and lift arms for re-alignment when reinstalling. It also says to do the same with the internal lift lever. However, that is for reinstalling the same parts. If I buy a new rockshaft and it is not keyed in any way (and certainly won't be marked), it would seem that the only important thing is the relative positions of the inside lever and outer arms. After installation of the rockshaft, but before putting on the lift arms, I could run the lift control all the way to the top and then put the lift arms on the shaft ends and also put the lift high-limit lever on at that same position. The lift all the way to the top and the lift arms also at the top seems a constant in every case I can think of. Here is a photo of the right side rockshaft on my tractor (not that it looks any different from the OP's).

Edit: I'm adding one more photo. Wouldn't it be cool if you could remove the toplink bracket on the rear of the lift casing and have an opening into the case to view and hold parts? (You can't) Check out my added photo.

Jim,

One can transfer witness mark from the old broken rockshat/lift arm and also on internal rockshaft/arm to the new shaft. That is enough with no reference material or as you suggested per the book. I agree about being able to holds part from the rear bracket but we can already do that with a helper from the front removing the cylinder head and then piston/cylinder sleeve. I saw your photo. The only bad part of fancier tractor is that you have to take a lot of stuff off just to get the darned lift cover.


The best thing is to have tandem external hyd lift with two cylinders externally mounted. That's the cat's meow.

JC,

 

[xtn]

I don't know anything about anything, but wouldn't it be possible to drive the old shaft out WITH the new shaft, just having the new one follow the old one through and keeping everything lined up?

xtn

 

[JC-jetro]

I don't know anything about anything, but wouldn't it be possible to drive the old shaft out WITH the new shaft, just having the new one follow the old one through and keeping everything lined up?

xtn

Yes or no, You can drive the old shaft out with the new shaft, but really nothing but the old shaft is holding the internal arm and the ram rod. It'll be "hole in one" for all to line up and get it done without damage to internal parts. The tolerances are quite tight.

JC,

 

[bsstreet]

thanks to previous posters for the info, enough yahs to intice me into giving it a try!

update: parts arrived. The shaft will slide out, fairly easily (after mods to Rops in the way) but only from right to left. Before pulling the shaft all the way out, I replaced it back across, but I did not have it fully off of the internal arm. I put a dowel in the right side as I was taking out the shaft from the left to keep the internal arm (#48) from dropping. When I went to slide the new shaft in, I can get it part way through, but could not get the shaft past the splines of the internal arm (#48). The new shaft appears off center in the arm opening and the arm piece is not fixed and wants to drop or move forward or back, so I could not seem to get it centered. After fidgeting with it an hour last night and again this afternoon, still no luck and the worst part (maybe) is that now I let the dowel slip out of the arm from the right hand side and the internal arm has fallen out of reach and sight.

Now the question(s) is/are...

Jinman, are you sure you can't look and feel inside the cover by removing the bracket (#2) from the back of the cover? is there no opening there? If not, I think its time for the entire cover to come off (meaning the seat/tank/lever covers/rops.....have to come off too which looks to be a real pita).

Could the arm be picked back up with a strong enough magnet?

any other suggestions???

Thanks again.

 

[jinman]

Jinman, are you sure you can't look and feel inside the cover by removing the bracket (#2) from the back of the cover? is there no opening there? If not, I think its time for the entire cover to come off (meaning the seat/tank/lever covers/rops.....have to come off too which looks to be a real pita).

Well, there's only four bolts to remove to find out. I don't think there is access under the cover, but it won't take much effort to remove and find out. I think it is time to start pulling your platform. Dropping the arm inside the casing pretty much guarantees you need a full disassembly. But what have you lost? If you didn't give it try, you'd never know whether you could do it or not. Removing the platform has always been the "official" way to remove the lift assy for access.

 

[JC-jetro]

Like I said on couple of occasions, one can have access to the internal lift arm without removing the lift cover. it requires a helper. One need to remove cylinder cover, piston and the cylinder liner to expose internal arm . it is not a difficult job.

JC,

 

[bsstreet]

Good update!! I was able to fish the dropped lift arm out using an improvised metal hook from both sides and get my dowel back in. AFter considerable more fidgeting, the new one went in slick as greased owl #@&%! My only concern is that now I cannot rotate the lift shaft by hand like I could before disassembly when it would move through about a 30 degree rotation. I did lower the hydraulic lever during removal of the seat while the engine was off and I have not started it back up. I have alot of other assembly before trying it out; I started removing seat/fenders etc, but decided to give the hooks a try when it looked like the floor below the seat was going to have to come off. I'll let you know where things go from here.

Anyway, I may not be out of the woods, but at least I feel like I am making firewood.

Many Thanks

 

[JC-jetro]

Do you know when the internal lift arm was as far as spline location when you dropped the external lift arm down prior to disassembly? if so , then did you duplicate the same angle (spline) after you fished out the internal arm?

JC,

 

[jinman]

Do you know when the internal lift arm was as far as spline location when you dropped the external lift arm down prior to disassembly? if so , then did you duplicate the same angle (spline) after you fished out the internal arm?

JC,

JC, I agree with you on most everythng, but this one has me scratchin' my head. I just don't see why the spline position matters. After you get the shaft in the lift lever, you run it to the top position and put on the lift arms. What could possibly be wrong with that? Maybe it's the upper limit sensing mechanism that has to be located in a specific position. I just don't know and I'd love to know what it is that could possibly be out of position. Is there anything keyed? I don't think so. Enquiring minds want to know. . . .

 

[JC-jetro]

JC, I agree with you on most everythng, but this one has me scratchin' my head. I just don't see why the spline position matters. After you get the shaft in the lift lever, you run it to the top position and put on the lift arms. What could possibly be wrong with that? Maybe it's the upper limit sensing mechanism that has to be located in a specific position. I just don't know and I'd love to know what it is that could possibly be out of position. Is there anything keyed? I don't think so. Enquiring minds want to know. . . .

Good morning Jim,

As you said the relative position of (shaft spline to lift arm) and (shaft spline internal arm) make no difference whatsoever and they are not keyed together.

The point that I'm making is what is the relative position of external arm and internal arm is as the splined shaft is set in place. Is the OP has ended up with the same position? That's the calibration importance. If the internal arm does not sees the full stroke of the lift cylinder then we have an issue. If it is bounds up then we have an issue. Some of the problem was mentioned here by the op after complete installation.

If the lift cover was removed then it would be easy to duplicate both arms relative position. If the cylinder head was removed for inspection again arms relative position could have been duplicated.

what's your take on my statement?

JC,


Edit: more info,

When I changed the piston seal on my tractor I removed implement on the 3 point, I lowered the external arm all the way and proceeded to remove head, piston and cylinder liner. The internal arm was at some position on the bottom. moving the outside arm and internal arm would go up and down. keeping the exterior arm at the lowest point and internal arm could be put at many different positions that could limit max or min piston travel. That's need to be avoided. If we had information like the angle between two arms around 30 degrees then the first installation of external would not matter as the rockshaft splines are uniformly distributed but the install of the next one become very important to duplicate the right angle.

 

[jinman]

what's your take on my statement?

JC,

I just don't know JC. You have worked with the lift and I have not done anything with mine except adjust the stop. I think the relative position of the arms can be indexed due to the splining on the shaft ends, but it might be off by plus or minus one spline and not be perfect. At the arm's end, one spline might be an inch or more in height and that would be a lot for the 3PH. Someone who does these on a regular basis might be able to do it, but a 1st-timer might have a tough time with it; especially working alone. What I have done is remove the operator platform on a "Dee-lux" model tractor. That job is an old-fashioned butt-kicking and I wouldn't wish that on anyone. If bsstreet can get this close enough to be satisfactory without removing the operator platform, then it is worth a try. I just hope nothing dropped out of position inside when his lift lever went "feral" on him.

 

[JC-jetro]

I just don't know JC. You have worked with the lift and I have not done anything with mine except adjust the stop. I think the relative position of the arms can be indexed due to the splining on the shaft ends, but it might be off by plus or minus one spline and not be perfect. At the arm's end, one spline might be an inch or more in height and that would be a lot for the 3PH. Someone who does these on a regular basis might be able to do it, but a 1st-timer might have a tough time with it; especially working alone. What I have done is remove the operator platform on a "Dee-lux" model tractor. That job is an old-fashioned butt-kicking and I wouldn't wish that on anyone. If bsstreet can get this close enough to be satisfactory without removing the operator platform, then it is worth a try. I just hope nothing dropped out of position inside when his lift lever went "feral" on him.

Jim,

I think one or two notches might prove critical if it ends up binding the arm at highest or lowest position. if the arms are raised up 1/2" Lower than normal might not be a big issue. What I have no doubt is if I remove the cylinder head I can then stick my arm in there and keep the arm steady. Following is the procedure I'd use to duplicate the angle.

Below is the picture of the front of the lift cover after the cylinder head/liner and piston removed. Ram rod is pinned to the internal arm. With the ram rod resting as it pictured I'd mark the external arm position with putting two witness marks , one on the arm and second on the lift cover side. I'd give no particular attention to splines at all. Once I remove the broken piece I proceed to insert the new rockshaft in without worrying at all on the splines as the splines are symmetrical. I'd use a helper to hold on to the ram rod and steady things out so to avoid binding of rock shaft and splines on the ram rod. Once I'm done with that, I'd rest the ram rod as it was before , hold it steady and in place and install the outside arms where I match up witness mark on the lift arm and side of lift cover. Doing so, I'm not really focused on splines but I'd be duplicating the same angle between inside arm and external lift arm. Pulling the ram rod in and out will change rotation of rockshaft to be avoided. I'm sure there is a written procedure for this. As said before this is a fantastic design by Shibaura. On many makes and model there is no choice, none whatsoever but to remove the whole lift cover

This is when we need RickB to chime in

 

[jinman]

This is when we need RickB to chime in

Something tells me that RickB is just a "fly on the wall" and being entertained by my/our musings.:laughing:

 

[JC-jetro]

Something tells me that RickB is just a "fly on the wall" and being entertained by my/our musings.:laughing:

I ditto that I bet you he is falling out of his chair laughing at my "expert opinion" here


JC,