Yanmar 187D - 4WD just quit on me

[Johndeere3720]

You know, I am pretty sure tractorernie has a 186d in his parts yard. He may have what you are looking for. There is one dealership out here that has a parts yard with yanmar, kubota, and several other brands. Im not sure if they have a 186 or 187D though, their tractors look like the imported units from japan, not the domestic tractors like the 186 or 187d.

 

[284 International]

I don't know what to tell you about pulling the pinion nut off. When I do an axle the pinion is left on the third member (axle housing) and the resistance of the tires on the ground lets me loosen the pinion nut. With the housing already broken, I'd be nervous about applying too much torque on a breaker bar with it screwed to the housing. You need a service manual to know what the torque is on these. It will probably have shims under the nut or the teeth of the pinion too. Keep track of those, too. I don't think these have a crush sleeve.

You really need to access a manual to know what the bearing preload and pinion depth are supposed to be as well. These gears are constantly driving, and the 4wd selector only connects the already spinning gears to the transmission. If the gears are improperly set up, they will wear out prematurely, even though these aren't such a high rpm as automotive gears are.

Make sure you verify the surfaces of the pinion holder are square and flat. Otherwise, when torqued down, it will stress the casting, the ears, and/or the weld, and it will likely crack and break again.

I would really spend 15 minutes on the phone with Tractor Ernie and the places Norm mentioned, and see if they have a replacement. I hope it works out, take photos of your repair for us!

 

[winston1]

May be wrong, won't be the first time, but, I believe those bearings are radial ball bearings and there won't be any preload on them. Some of the bigger Yanmars have tapered roller bearing there and they do have a preload. I believe those bearings are held apart and correctly by a spacer between them and snap rings. Still believe only adjustment you have is the shims for correct backlash. Of course, the flange on the housing being true is very important.

 

[284 International]

Thanks Winston. I obviously don't know, but knew someone would, what/if the situation of the bearings are. The only things I've ever done have been automobile axles. This is why he needs access, one way or another, to a manual.:thumbsup:

 

[winston1]

Thanks Winston. I obviously don't know, but knew someone would, what/if the situation of the bearings are. The only things I've ever done have been automobile axles. This is why he needs access, one way or another, to a manual.:thumbsup:

I agree! Going to try and attach a John Deere drawing. Probably won't work.

 

[DWeinreich]

Winston1-that JDeere diagram is really helpful and now I get what the broken #23 ring does. Got the welding equipment and nickel rod ready to go so if the weather holds I'll try reattaching the busted ears this weekend. The guy at the welding supply shop thought the ears are cast steel not cast iron. Either way he said the nickel rod was the right thing. I'm going to pull the whole axle out from under the tractor to make it easier to work on. I'll post some process pix if all goes well. Meantime I have to find some roll pins to replace the one that came out in two pieces when the u-joint was disassembled.

Thanks for all the advise so far.

 

[California]

I have to find some roll pins to replace the one that came out in two pieces when the u-joint was disassembled.

They used a small rollpin inside a larger one in many cases. Metric, and a little hard to find.

 

[284 International]

The local "Do It Best Home Center" has those metric roll pins. It was formerly a large Ace hardware; both brands carried them.

 

[Gary Sweat]

They used a small rollpin inside a larger one in many cases. Metric, and a little hard to find.

In case you have never done them, the slots in the 2 pins should be 180 degrees from each other according to the service manual.

 

[DWeinreich]

Weather is about 30 degrees so I set to working on the tractor. I want to pull the whole front end out by pulling the pivot pin BUT can't do it without disconnecting the steering linkage. This looked simple but when I removed the castle nut from the swivel joint it won't budge. Tried pounding on it with a hammer and wood block but no-go. Here's a picture. Any ideas how to get the ball joint bolt out of its hole? Is it threaded? If so where do get a wrench on it?

 

[Gary Sweat]

Weather is about 30 degrees so I set to working on the tractor. I want to pull the whole front end out by pulling the pivot pin BUT can't do it without disconnecting the steering linkage. This looked simple but when I removed the castle nut from the swivel joint it won't budge. Tried pounding on it with a hammer and wood block but no-go. Here's a picture. Any ideas how to get the ball joint bolt out of its hole? Is it threaded? If so where do get a wrench on it?

There are several types of tools to remove it. Be careful pounding on the threaded end, there easy to damage the threads. You can usually rent these at a auto parts store and some will loan them for free.

 

[DWeinreich]

So there are no female threads holding the stud in?

 

[Gary Sweat]

So there are no female threads holding the stud in?

It's a tapered shaft that gets stuck from pressure and rust. The nut just pulls the shaft down into the taper to hold it.

 

[winston1]

Sometimes you can put a large hammer on one side of that lower part, take another pretty good size hammer and strike it just oppisite of the backup and it will pop right out.

 

[DWeinreich]

Got her out. Thanks gents!

 

[California]

On reassembly, I wonder if you could rotate the tailshaft to put the welds on top and sound metal on the bottom side.

 

[Johndeere3720]

If it is threaded, why not push the dirt out of the hole on the end of the bolt and use a screw driver to try and turn it? Then when it is loose enough it can be done with a vice grip. When I replaced one of the seals on my front axle, i just unbolted the steering mechanism from the axle. I'm not sure but my 169D's axle looks almost exactly the same as yours.

 

[DWeinreich]

Here are pictures from the day's work. The question is whether the pinion gear is ok. I suspect it is, but here's an image of it.

Never got to the final weld up today. But the pieces are prepped with U shaped grooves. Once the fronts are welded I'll groove out the machined face and weld the back, then grind the welds flush so the alignment stays true. Darkness and cold caught shut things down for now...it will have to wait a couple of weeks till I get back to it. It will be interesting to see if the nickel welding rod works.

The SAE roll pins didn't fit the u joint so I have to look for metric ones. And also a metric O ring seal.

The advice from you-all has been just great. Thank you.

 

[winston1]

DWeinreich, maybe i missed something but it would appear you have removed the pinion holder housing from the differential housing. Mind sharing how you did this? Does look like your pinion has suffered a little abuse but with good lube I suspect it will out last you. Forget about my question, I read the answer on Tractor Support.

 

[DWeinreich]

Sure Winston1. Here's what I remember.

Drain the gear oil out of the front axle.

Jack up the front of the tractor and put it on stands.

Disconnect the drive shaft from the front u joint by removing the circlips and driving out the nested roll pins (both ends of the u joint). This took a punch and some pounding. Slide the drive shaft back.

Disconnect the drag rod at the forward ball joint. This required removing the castle nut and pounding the threaded stud upward with a hammer and block of hardwood to protect the threads. It was stubborn and had to be torch warmed and tunked side to side to break the bond.

Lower the tractor till the front wheels just touch the ground and the center pin has no load on it.

Support the pinion holder with a small jack to take the torque off the center pin.

Take out the center pin (four 17mm bolts, set in lock tight).

Jack the tractor up and off the front axle assembly and wheel it out.

Back out the four pinion holder bolts and wiggle it out of the axle case. The pinion bearing is a snug fit but will come out of the hole. Take care not to damage the o ring seal on the pinion holder.