Steering broke YM186D

[California]

First real problem I've ever had, running Yanmars since 2003: My steering went crunch on the little YM186d and quit responding. The shaft is now an inch too high coming out of the top of the steering column. There is absolutely no left turn action at all. Steering right has some minor influence on the direction it wants to go. I had to put my wife on the tractor and walk alongside, forcing the direction the wheels were pointed using a long pole, to get back to the barn.

Has anyone overhauled a steering box? Advice?

I have the Shop Manual to describe dis-assembly. Pulling the cowl looks like a nuisance.

Comments?

Thanks in advance!

 

[Soundguy]

likely a thrust bearing or bushing died.

I've rebuilt just about every manual steering box on all my tractors.. not much mor ethan sectors and worm gears.. sometimes a recirculating ballnut.. that and bushings, bearings and seals..


soundguy

 

[Gary Sweat]

First real problem I've ever had, running Yanmars since 2003: My steering went crunch on the little YM186d and quit responding. The shaft is now an inch too high coming out of the top of the steering column. There is absolutely no left turn action at all. Steering right has some minor influence on the direction it wants to go. I had to put my wife on the tractor and walk alongside, forcing the direction the wheels were pointed using a long pole, to get back to the barn.

Has anyone overhauled a steering box? Advice?

I have the Shop Manual to describe dis-assembly. Pulling the cowl looks like a nuisance.

Comments?

Thanks in advance!

You may have broken the ball nut or a tooth off the sector shaft. Not hard to replace the parts but can be a little difficult getting the arm off the sector shaft. You have to use a stout wheel puller and patience. I did a complete rebuild of mine. Easier to work on if you take the whole steering box out of the tractor but it can be done by just sliding the steering shaft up off the box. Just makes it a little cramped to work on if you leave it in the tractor. Hoyes video covers the steps pretty good.

 

[California]

Thanks Chris. It's good to hear from someone who has BTDT. This doesn't sound so scary if it's just the $15 upper and lower bearings. I hope ...


And Gary, thanks for your experience, and your reference to the Hoye steering rebuild video. I'll go watch it now.

 

[winston1]

Hoye also has these printed instructions. Yanmar Tractor Steering Shaft Fix

 

[Soundguy]

Thanks Chris. It's good to hear from someone who has BTDT. This doesn't sound so scary if it's just the $15 upper and lower bearings. I hope ...


And Gary, thanks for your experience, and your reference to the Hoye steering rebuild video. I'll go watch it now.

PS I don't like to dink with.. bt manual boxes are generally easy and self evident.

you'll be fine as long as you can get parts.

soundguy

 

[284 International]

California, I'm sorry to hear about your breakage. I'm interested to see the teardown and repair though, as well as the failure analysis. It seems as if it's an improbable event. You don't have a loader or anything like that to stress the steering box. It seems odd. I've never broken a steering box in anything before, although I've steered a couple Jeeps and 3 full sized pickups out of places after breaking Pitman arms (or the associated balljoints) with the long branch and bravery method....:laughing:

 

[Soundguy]

lack of lube, then resulting thrust bearing failure is common on the boxes I've fixed. these are of course, symptoms of a different problem.. leaky sector seals.. etc.

soundguy

 

[California]

Next question - how the heck do I dis-assemble the column shift (Powershift) linkage to pull the dashboard and cowl? With it still in place and the rest of the cowl loose, there was a little wiggle room to get the steering column out. But it will be impossible to push the steering column back through the dash grommet at such an angle to re assemble it. That column shift assembly appears to run through a tube with linkages welded on *both* ends.

I took the steering column and steering box out as separate pieces. But according to the manual the cowl has to be removed to install the rebuilt column intact. These parts also need to be removed to install the steering box bolts beneath the gas tank.

Has someone done this? The service manual covers only the floor-shift version and says the cowl, and the fuel tank and its mount, have to be removed. But with the column shift linkage a single massive welded assembly, I can't see how to remove it.

 

[California]

Failure mode: just what Soundguy said. (He is one of the original gurus here, co-founder of this TBN Yanmar Forum in fact, for those of you haven't yet met him).

There was bad rust all down the steering shaft. Then nothing left of the upper shaft bearing where the steering shaft enters the box, just a fragment of its ball cage. This explains how the steering wheel became higher.

The bearing at the bottom of the steering shaft had a few balls left in its cage. When I bought the tractor I noticed the steering wheel dragged on the top of the steering column sleeve, and added a washer under the steering wheel. So the lower bearing must have been bad for a while to let the steering wheel settle down like that.

Also, the end of the Pitman shaft that engages the adjuster doesn't look like I expected. I thought it should have a groove that let the adjuster pull against it. Is that correct? It's end had one tab standing without such a groove, and apparently broken at its outer end, and the other tab apparently snapped off. What should the adjustment end of the Pitman arm look like? Does the adjuster only push against it?

 

[Soundguy]

can't help ya on that as I don't have a parts manual.. but you found what I expected.. shelled out thrust bearings.. that's the #1 failure I see on mnaual boxes.. that and lack of lube and bad seals.

I usually pump gearboxes full of 0# or 00# grease after I rebuild them..

soundguy

 

[winston1]

Here is a couple of scans out of my 226 manual. Might be similiar to yours. May not help. Interesting, the 226 manual specs out Multi-purpose grease.

 

[California]

Here's a photo.

 

[Soundguy]

on a ford that would have had 2 ears, and an adjuster stud with a wide head that was under then ears to push / pull the sector... quite similar design...

soundguy

 

[winston1]

Failure mode: just what Soundguy said. (He is one of the original gurus here, co-founder of this TBN Yanmar Forum in fact, for those of you haven't yet met him).

There was bad rust all down the steering shaft. Then nothing left of the upper shaft bearing where the steering shaft enters the box, just a fragment of its ball cage. This explains how the steering wheel became higher.

The bearing at the bottom of the steering shaft had a few balls left in its cage. When I bought the tractor I noticed the steering wheel dragged on the top of the steering column sleeve, and added a washer under the steering wheel. So the lower bearing must have been bad for a while to let the steering wheel settle down like that.

Also, the end of the Pitman shaft that engages the adjuster doesn't look like I expected. I thought it should have a groove that let the adjuster pull against it. Is that correct? It's end had one tab standing without such a groove, and apparently broken at its outer end, and the other tab apparently snapped off. What should the adjustment end of the Pitman arm look like? Does the adjuster only push against it?

I believe it only pushes as I believe Aarons video says the tabs are for holding the shaft as you adjust. Believe he said as long as you can make your adjustment it would be ok. All the steering boxes I have ever messed with do the tightening as you screw the adjustment screw in so that makes sense.

 

[California]

I think there should be ears and they are snapped off - and in fact have been gone for a while. I tried adjusting the stud when I bought the tractor in 2009 and nothing I did reduced the slack in the steering wheel.

 

[Soundguy]

if the ears are there it WILL pull.. however as for adjusting OUT backlash.. then push is the most important.

easy to fix in any case.. just a single welding rod and some mild steel and grinder work...

BTDT

soundguy

 

[Soundguy]

make sure the bore the stud rides in is not stripped. IE.. the sector cover. if it is stripped.. you can't put pressure on the sector gear to reduce play / backlash clearance.


soundguy

 

[California]

Here is a couple of scans out of my 226 manual

Winston, thanks! That shift gate/sleeve assembly, D in the second diagram, is also a single welded piece on mine. The lower end of the sleeve is clamped to the firewall. It looks like I need to loosen that clamp (G) and slide D up out of the dashboard. I don't have a diagram like yours showing the column-shift linkage in my 1980 parts manual or my later service manual.

SG, it seems like it would take a milling machine to cut that groove after adding material. That's over my head! At least the threads in the sector cover are good.

I think I am headed for a rebuilt exchange unit considering that I also need the Pitman shaft bushing and seal, and the bearing surface at the bottom of the steering shaft shows some galling. I haven't looked at the recirculating balls yet but I expect there is slack there too. I suspect there have been shattered ball bearings floating around in this steering box for years. Does anyone know if these steering boxes share components with Nissan etc? The ball bearings are obviously generic and if I could find an inexpensive Pitman shaft (specced for Datsun etc), I might take that approach.

 

[shawnjvl]

Winston, thanks! That shift gate/sleeve assembly, D in the second diagram, is also a single welded piece on mine. The lower end of the sleeve is clamped to the firewall. It looks like I need to loosen that clamp (G) and slide D up out of the dashboard. I don't have a diagram like yours showing the column-shift linkage in my 1980 parts manual or my later service manual.

SG, it seems like it would take a milling machine to cut that groove after adding material. That's over my head! At least the threads in the sector cover are good.

I see that Hoye sells only a rebuilt box exchange, not components. And I've seen that the Pitman shaft for other applications is expensive. I think I am headed for a rebuilt exchange unit considering that I also need the Pitman shaft bushing and seal, and the bearing surface at the bottom of the steering shaft shows some galling. I haven't looked at the recirculating balls yet but I expect there is slack there too. I suspect there have been shattered ball bearings floating around in this steering box for years. Does anyone know if these steering boxes share components with Nissan etc? The ball bearings are obviously generic and if I could find an inexpensive Pitman shaft (specced for Datsun etc), I might take that approach.

Here's a picture of the sector shaft available from Hoye