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steering problem

Discussion in 'Yanmar' started by chrpmaster, Apr 24, 2008.

  1. chrpmaster

    chrpmaster New Member

    May 5, 2004
    I have been scratching my head over this one. I have a YM135 and the steering is very loose. I can turn the steering wheel over half a turn before the front wheels move. I read in my owners manual how to adjust it by tightening the adjustment screw on the right side of the steering box. I turned it clockwise as far as I could and still have the lock nut on it and it made no difference. Is it possible for that screw to become unhooked?

    I know the previous owner had problems with the steering after I agreed to buy it but before I picked it up. He said he had to remove the steering wheel and shaft then open the steering box to replace some parts to get it to work. It does steer but is very loose.

    Any other suggestions?

  2. mark777

    mark777 New Member

    Jul 23, 2004

    How are the connections at the drag link, intermediate shaft and pitman arm ball joints? If it’s possible, get someone to sit in the operator area, move the steering wheel slowly side to side while you inspect (before static-when front wheels actually move) how much play at all the steering connections.


    If the steering shafts are within tolerances there is a good possibility that the shims in the column are misaligned or fallen away from your adjustment screw. Do you have an exploded view of the box components that show the ball nut assembly AND the shims? As I recall, the previous owner replaced the steering with used and maybe he didn’t realize or notice the shims (maybe ??).

  3. mark777

    mark777 New Member

    Jul 23, 2004

    You might have this in your shop manual…it’s #14 in this attachment (SHIM). Critical to end play which allows the adjustment screw to operate within tolerances….


    Attached Files:

  4. chrpmaster

    chrpmaster New Member

    May 5, 2004
    Hmmm the other parts of the steering mechanism seem ok to me. Nothing seems too loose. In fact nothing really starts moving until steering wheel is turned half a turn.

    I am guessing I will need to disassemble the steering box to get to the shims? I don't remember whether he used new parts or not. Do I need to remove the steering wheel and shaft etc?

  5. mark777

    mark777 New Member

    Jul 23, 2004
    The shims compensate for the end play. Which is telescoped as lash (play) at the steering wheel.

    I think the simplest way is to disconnect the shaft from the pitman arm, remove the column, box and the dash panel at the same time and examine the entire assembly to see why there's so much play.

    Adding (or removing) the shims align the worm shaft to the ball nut assembly and center the shaft column. Too far off center left, or right, is what causes excessive slop, partially disengages worm gear travel and allow gear threads to miss some engagement at either end.

    Although the Yanmar steering box is a little more complicated (sophisticated) than this...think of the entire assembly as working on the same principal of a trailer tongue screw jack. At the start...IF the crank rod threaded shaft is in the center (neutral or 0°) it will allow optimum lift height when fully turned clock wise. And fully lowered when cranked CCW.

    If the same tongue jack is NOT at 0° at the start, It will either not lift high enough because it's run out of thread travel - or - not lower enough because it's also run out of thread travel. Does this help at all?
  6. chrpmaster

    chrpmaster New Member

    May 5, 2004
    Yes that helps Mark.

    I also saw a discription on Hoye's web site showing the repair of the Yanmar steering. I think between your help and theirs I should be OK. I hope it is just shims either not being there or too many being used. I'll work on it and let you know.

  7. chrpmaster

    chrpmaster New Member

    May 5, 2004
    Steering problem update

    Well I noticed I originally posted this question last year. I finally got around to fixing it a few days ago. So get yourself another cup of coffee or another beer and get comfortable cause this could take a while.

    If you reread the previous posts on this thread you know I was concerned about how loose the steering was on my Yanmar. As you can see from the dates it was just at the beginning of the mowing season that I posted this question and Mark777 was kind enough to try to help me. Of course life intruded and since the steering still worked and the grass was growing I put off the fix "until I could get around to it". That happens a lot to me.

    Any way I continued to use the tractor all summer mainly mowing my yard pulling a Woods L59 finish mower I picked up for $200. Yes I know its probably too much mower for the tractor but I got such a good deal on it and the Yanmar did pretty well with it so I used what I had.

    All I can say is what a mowing machine! That little Yanny just kept on working and the mower cut so nice it looked like I push mowed it. Plus it got my lawn mowing done in 25% less time. Not bad for $1400.

    Anyway I got pretty good anticipating turns and maneuvering with the loose steering. But I noticed that it seemed to slowly get worse as the summer progressed. Finally towards September the steering was getting so loose that I could turn the steering wheel almost a full turn before the wheels would move. Needless to say it made for some exciting times mowing around trees!

    My goal was to finish the mowing season and then rebuild it correctly. Well I almost made it. Just when the leaves started falling I was finishing up a days mowing and the steering gave out. I could now turn the steering wheel and the front tires never moved. Luckily I was near the shop and just walked it in the shop and shut it down. I intended to get to it sooner but again life got in the way.

    So that brings you up to date on this saga. My next posts will show the repairs made.
  8. chrpmaster

    chrpmaster New Member

    May 5, 2004
    Well a couple weeks ago I finally got time to fix the littly yanny.

    Here is a pic of the it with the hood open.

    <a href="http://s14.photobucket.com/albums/a332/chrpmaster/?action=view&current=steeringfix014.jpg" target="_blank"><img src="http://i14.photobucket.com/albums/a332/chrpmaster/steeringfix014.jpg" border="0" alt="Yanmar engine left side"></a>

    and another

    <a href="http://s14.photobucket.com/albums/a332/chrpmaster/?action=view&current=steeringfix015.jpg" target="_blank"><img src="http://i14.photobucket.com/albums/a332/chrpmaster/steeringfix015.jpg" border="0" alt="Yanmar hood open"></a>

    This is where the steering shaft should be. It mounts just behind the tank and battery and just in front of the silver sticker. It just bolts to the frame.

    <a href="http://s14.photobucket.com/albums/a332/chrpmaster/?action=view&current=steeringfix016.jpg" target="_blank"><img src="http://i14.photobucket.com/albums/a332/chrpmaster/steeringfix016.jpg" border="0" alt="Yanmar steering removed"></a>

    More to come
  9. chrpmaster

    chrpmaster New Member

    May 5, 2004
    OK now to the steering shaft itself

    This is what it looks like when its in one piece.

    <a href="http://s14.photobucket.com/albums/a332/chrpmaster/?action=view&current=steeringfix020.jpg" target="_blank"><img src="http://i14.photobucket.com/albums/a332/chrpmaster/steeringfix020.jpg" border="0" alt="Yanmar steering fix"></a>

    This is the steering box that has all the moving parts in it.

    <a href="http://s14.photobucket.com/albums/a332/chrpmaster/?action=view&current=steeringfix011.jpg" target="_blank"><img src="http://i14.photobucket.com/albums/a332/chrpmaster/steeringfix011.jpg" border="0" alt="Yanmar steering box right side"></a>

    And another from the other side. You can see the orange oil seal I replaced. The bolt holes on the bottom are where its bolted to the frame.

    <a href="http://s14.photobucket.com/albums/a332/chrpmaster/?action=view&current=steeringfix013.jpg" target="_blank"><img src="http://i14.photobucket.com/albums/a332/chrpmaster/steeringfix013.jpg" border="0" alt="Yanmar steering box"></a>
  10. chrpmaster

    chrpmaster New Member

    May 5, 2004
    One thing I didn't mention before was I was surprised how dirty the oil was inside this. It looked black and was really grungy. It tool a lot of time and flushing to get it all out. The dealer said in their instuctions to make sure this is very clean since any leftover dirt will grind at your new bearings and could cause them to fail faster than normal. Needless to say I have no desire to ever do this again so I made sure this thing was clean before I started reassembly.

    This is a pic of the new bearings I installed in the bottom of the steering box. I had to tap them into the race molded into the bottom of the steering box.

    <a href="http://s14.photobucket.com/albums/a332/chrpmaster/?action=view&current=steeringfix010.jpg" target="_blank"><img src="http://i14.photobucket.com/albums/a332/chrpmaster/steeringfix010.jpg" border="0" alt="Photobucket"></a>

    <a href="http://s14.photobucket.com/albums/a332/chrpmaster/?action=view&current=steeringfix012.jpg" target="_blank"><img src="http://i14.photobucket.com/albums/a332/chrpmaster/steeringfix012.jpg" border="0" alt="Yanmar steering box with new bearing"></a>

    This is the steering shaft before I bolted the steering tube on. You can see the upper bearings on the shaft. They are identical to the ones I installed in the bottom of the steering box.

    <a href="http://s14.photobucket.com/albums/a332/chrpmaster/?action=view&current=steeringfix018.jpg" target="_blank"><img src="http://i14.photobucket.com/albums/a332/chrpmaster/steeringfix018.jpg" border="0" alt="Yanmar steering fix"></a>
  11. chrpmaster

    chrpmaster New Member

    May 5, 2004
    The next step was to install the steering tube and shim it properly. I found this to be the hardest part. This must be done correctly because the steering tube must put the correct amount of pressure on the bearings to prevent the steering wheel from moving up and down in the steering tube and the bearings could get out of their grooves. Plus if its too tight it will grind the bearings into dust and be hard to steer.

    I thought I could just reuse the old shims but was wrong. I finally made my own homemade shims from some washers I cut in half. Not what is recommended by the manufacturer but it works fine. I put one on each corner of the steering box when I bolted the steering tube back on and it was just right. I also needed to use some gasket sealant to "caulk" up the gaps so no gear oil would leak out. It should work but I will find out as I use it more.

    <a href="http://s14.photobucket.com/albums/a332/chrpmaster/?action=view&current=steeringfix021.jpg" target="_blank"><img src="http://i14.photobucket.com/albums/a332/chrpmaster/steeringfix021.jpg" border="0" alt="homemade shims"></a>

    This is the reassembled steering shaft ready to be reinstalled in the tractor. The shaft sticking out the left side is what attaches to the steering pitman arm. Actually I think its easier to see its shadow and follow it up.

    <a href="http://s14.photobucket.com/albums/a332/chrpmaster/?action=view&current=steeringfix024.jpg" target="_blank"><img src="http://i14.photobucket.com/albums/a332/chrpmaster/steeringfix024.jpg" border="0" alt="Yanmar steering fix"></a>
  12. chrpmaster

    chrpmaster New Member

    May 5, 2004
    I have to get some pics of it installed on the tractor. It got too late and I forgot. But it is on the tractor and works much better than when I first got the tractor. It is still a little loose but I figure not bad for a 30 year old tractor.

    I was also impressed when it started right up after sitting for 6 months. I had turned off the fuel petcock to prevent it dripping on the floor. It was cold in the shop cause I didn't get around to starting up the stove and it was in the teens outside. But the little diesel sounded pretty good. I let it warm up for about 10 minutes before I shut it off. I had forgotten how quickly it can fumigate my little shop.

    I have some electrical stuff I want to do. Some are important like making sure the temp light works and some are just upgrades the tractor didn't originally come with like a voltage meter and maybe some more gauges versus idiot lights.

    Hopefully I can take it out for a test drive this week if the weather and work cooperates. I will post pics as I make more progress.

    Originally I was going to repaint it red like some of the newer Yanmars and because I don't like the pea green color. But after using it all summer the color kind of grew on me so we will see.

    Hope you enjoyed this little project. Sorry for the crappy picture quality. I blame the cheap camera but if pressed I would have to admit some operator error.:dazed:

  13. DanielWilson

    DanielWilson New Member

    Feb 2, 2009
    Thanks for the pictorial how-to.

    So ... it was basically the bearings in the steering box that needed to be replaced?

    SHARTEL New Member

    Feb 11, 2009
    Great read Andy!

    Sorry for the late post but I’m catching up on a few things I missed. This thread is an excellent tutorial and gives others the confidence to tear into a steering box.

    Those homemade shims must be a critical thinkness…how did you measure them? A micrometer or calipers?? Is the fill tube (90 wt. oil) plug on the reverse side of your little 135? Mine is, and it makes it darn near impossible to fill and very difficult to drain without removing components.

    Crappy Japanese bearings. Only lasted thirty years :D !

  15. Live Oak

    Live Oak New Member

    Dec 21, 2003
    OUTSTANDING post and photography! :thumbsup: I LOVE LOTS of pictures! :D

    I think the Spring tractor bug must have got you Andy. Great post!