We purchased a used 1816B some years ago, probably the third owner, that has been a big disappointment. The seller said that the hydraulics were "a little jumpy" - that was an understatement. I only know of one other 1816 unit whose owner says his does it and it is the nature of the beast (but I don't think so). Of course, it is more pronounced when cold, and more amplified when we installed a Kohler Command Twin. I've gone through the machine several times over the years tightening the belts, adjusting the control lever linkage, tightening the chains, checking the oil pressure, inspecting the check valves, etc., but found nothing that points to the problem and a solution. Also, one side always appears to be "weaker" than the other. When the clutch is engaged and with the control levers (they are "touchy") in neutral, as you VERY CAREFULLY inch the control levers forward (or reverse), you can feel the unit beginning to get power when all of a sudden it will violently lurch forward (one side or the other - you never know) in a dangerously out-of-control manner. It is almost like what would happen if you had the engine running full throttle and slammed the control lever full forward. Releasing the controls to neutral will cause it to buck wildly back-and-forth as you frantically disengage the clutch to get it to stop. We keep the engine at near idle because full throttle is just way too dangerous. Once you get it underway, you can increase engine speed, but it is uncomfortably "jumpy". We have checked the charge pressure, system pressure, pressure at the relief valves, and all appear to be within normal limits. We had the motors bench-tested, but not the pumps (just pressure checked). We have changed the oil and filters according to the service manual. We thought it might be an oil flow problem, but once you can get it moving, it has lots of power to the point you can kill the engine if you plant the bucket. We are at a loss for an answer, and any ideas would be appreciated.
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I sit hydrostatic drive?
If so, try removing the linkages to the pump and check for wear on all parts. I have an S250 that had wear on the square blocks taht held on to the swash plates on the pump. You would slowly move the levers forward then all of a sudden it would jump forward. I machined and shimmed the linkages, now it's spot on.
Hopefully your issue is just as simple to repair.
If so, try removing the linkages to the pump and check for wear on all parts. I have an S250 that had wear on the square blocks taht held on to the swash plates on the pump. You would slowly move the levers forward then all of a sudden it would jump forward. I machined and shimmed the linkages, now it's spot on.
Hopefully your issue is just as simple to repair.
SkidRoe
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Have you checked your charge pressure? I am not sure if these units have a separate charge pump, or if it bleeds pressure off of the loader pump. I could see if your charge pressure were low (or non-existent) where you could be pushing on the levers, then suddenly it gets a gulp of oil, then lurches forward. Just a guess, worth what you paid for it... Cheers - SR
Thanks for your thoughts. I have checked the charge pressure, and it matches the values given in the service manual. The only time I had pressure issues was when one of the drive belts was slipping. Tightened belts did not solve this problem. I am thinking about buying a flow meter and see if it tells me more than just a pressure check.
Your thoughts on the linkage is interesting. I will take another look at the linkage, and do another readjustment. I have never been very impressed with the linkage design in this unit.
I can tell you it is not an inherent problem with the machine. I've had 2 1816s. The second one was exactly what you describe. It bucked so violently I was concerned about it rolling over on completely flat and level ground. I sold it to a shop that specialized in hydraulics, and I got to run it a little after they had worked on it. It drove perfectly. It was as smooth and gentle as could be. I asked them what they did, and all they said is that they adjusted the sticks. So, it can be done. I wish I had watched them, because it was a spectacular transformation.
Boy, I wished you had watched, too, so that you could tell me exactly what they did. I have adjusted that linkage until I am blue in the face. As soon as the weather improves here, I'm going to get it out of winter storage, put it up on blocks, and take another shot at that linkage. There must be something that I'm (and have been) overlooking on that thing.
Hotrod1830
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If you have worn/loose linkage parts it will do that. That is my guess. If anything is loose or allowed to move it will amplify your stick input. Sometimes when a drive pump is going out it will do something simular, but they dont do it for very long before they fail completely.
Thanks, Hodrod, the consensus seems to be that it is a linkage problem, so next week I am gonna dive into it once again, and hopefully find some overlooked problem. I am gonna take a hard look at those shock absorber cylinders, too. This thing has done this for years, so I don't think it is the pump (I hope).
Also, do you know if those pump swash plate shaft pivot links need to be tight on the pump shaft (they seem to be design to ... pivot)? On my OMC 310, those links are bolted down tight in a spring assembly to return it to neutral, and the linkage is very straight forward. As you say, the mechanism in the 1816B will just amplify any problem.
Hotrod1830
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Going off the parts diagram, it looks like it should pivot. What I am talking about is "slop" in the controls. When you move the stick forward or backward, you should see the swash plate move the same, without any "play" in the linkage. From what you describe, you are looking for grossly worn or loose parts. FWIW, even when my 1830 was operating correctly, it could be a bear to operate sometimes. I got in the habit of operating it with my knee's pushing up against the sides of the sticks to keep them steady. If I didnt, it would start jerking and bouncing until I finally had to let go of the sticks and let it settle before going again. The newer stuff doesnt have that probelm because they usually have a lap bar that your arms are resting on, and it helps you steady the sticks. The older stuff doesnt have anything, and as soon as YOU start bouncing around, it is directly transfered to the sticks which in turn makes the bouncing worse. Yes, it can get to the point you think your gonna tip over. If you havent already, try steadying the sticks with your knees and see if that helps at all. Even if the shocks are good, it still wont eliminate what I am talking about.
First off, I want to thank you gentlemen for pointing me in the right direction, and causing me to focus on just the control linkage as the source of my problem. In summary, the problem was excessive play in the Pivot Links on both pumps, and the neutral control adjustment on the left side. It now operates very smoothly. If you want to know more about my experience, read on. The first problem I had was with the service manual for the unit. It is from a well-known third-party provider, part # CA-S-1816UNILR, and about 600 pages. Apparently, every seller of this manual (not the $160 primo manual) gets it from the same source. Although for the 1816 Uni-loader, the information is not for the 1816B. The information on the control linkage does NOT match up with my 1816B. For example, the figures in Section 6034 – Hydrostatic Controls are not for the 1816B (maybe the earlier 1816?). The bell-cranks are manufactured differently, and the adjustable links both attach in the center of the unit and not to the left sides of the pumps. You cannot align it by their instruction that the swash plate control arms and the inner arm on the bell-cranks should be straight up-and-down – not gonna happen. You want to go out to the online parts manuals, and download the correct drawings. I suspicion that the previous owner(s) may have attempted to use this information, and got it out-of-adjustment. The play in the Pivot Links was caused by securing the bolt with a lock nut but not tightening it, and using full-thread 3/16-inch bolts (called for in the parts list) that, by the nature of being threaded, are just slightly less that 3/16-inch. I got some bolts that were not full-thread, acted more like a pin, and had just enough thread to tighten the Pivot Link Yolk to the pump shaft. No more slop in the linkage at the pump! If I have any future problems with these cheap Pivot Links, I am going to replace them with the style found on my OMC 310 – a much better design. Since the control adjustment procedure in my service manual is bogus, I took a different tact. First, I eliminated the free travel in the neutral controls without regard to the bell-cranks. Next, I measured the Pivot Link arm travel from full reverse to full forward. Total travel was just 1-inch, and I noted that pump neutral would be half the distance (1/2-inch). I adjusted the Pump Control Rods to reflect half the travel distance to be in neutral position, and secured them to the bell cranks. When I buttoned everything back up, the controls were spot-on without further adjustment, and the unit seems to be operating smoothly – better than EVER! Tomorrow is the acid test where I use the 1816B to load manure from the barns. When it works, the 1816B is so much more efficient loading than the loader tractor. Wish me luck, and THANKS again.
