Might be getting back into a Yanmar

[Johndeere3720]

It’s certainly been a while, almost 10 years ago I sold my YM169D to purchase my first skidsteer. Today I do excavation full time with several newer bobcat machines but still have a soft spot for the 80’s US market Yanmar tractors. This afternoon I’m going to go look at this YM186D, apparently it needs charging system work and the front axle needs resealed. Nothing too crazy, hoping to pick up a small finish mower for it to mow around my yard space. Anything I should look out for specifically aside from the basics?

 

[rScotty]

It looks like you've found a keeper. A good YM186/187D runs like a watch. Very quiet. The biggest difference being that the 187 has more legroom.

If you get real lucky, some of the YM186Ds were sold or outfitted later with Yanmar's (perpetually leaky) unique steering linkage type of powersteering assist system.

Even luckier, and you will get the manuals, too.

If the front axle leaks, you may be in for a complete tear down and replace of bearings and seals...or it may just be the seals. But even a complete rebuild is no biggie as the parts are so nicely machined and fit well. Just take your time and keep the shims in order.
And if it is only worn seals but not bearings - i.e. no stub-axle slop - then it will do no harm to just add oil as needed for years if need be.

I suspect you are capable of doing the electrics. They are very basic.

I hope you do get it, and would love to have one that nice fall into my lap here.
If I think of anything else I'll add it.
rScotty

 

[winston1]

Several have had success adding Lucas stop leak on the axles. Might depend on how bad the leak.

 

[bmaverick]

It’s certainly been a while, almost 10 years ago I sold my YM169D to purchase my first skidsteer. Today I do excavation full time with several newer bobcat machines but still have a soft spot for the 80’s US market Yanmar tractors. This afternoon I’m going to go look at this YM186D, apparently it needs charging system work and the front axle needs resealed. Nothing too crazy, hoping to pick up a small finish mower for it to mow around my yard space. Anything I should look out for specifically aside from the basics?

View attachment 698224

WOW. That machine looks better than the 2019 posting of a Museum Mint Quality YM336 that the guy wanted a few gold coins for.

These machines came with an OE ROPs. You could inquire if that was still with the seller.

A wonderful find. We'll love to hear more about this nice machine and soon!

 

[Johndeere3720]

Well it ended up on my trailer this afternoon

Needs a little work but it’s a great running, driving little tractor. More to come soon

 

[Smokeonthewater]

That's PURDY...

 

[bmaverick]

Well it ended up on my trailer this afternoon

Needs a little work but it’s a great running, driving little tractor. More to come soon
View attachment 698301

That fender style would accept many of the tractor soft-fabric cabs out on the market. NICE.

 

[California]

Wow, its gorgeous!!! And welcome home!

If the charging is erratic and you've cleaned the connections, replace the regulator. It's a near-universal one matched to the later pancake alternator, the one that needs external diodes. If its six-wire then it will fit. About $30 on Ebay and may say for some mower, excavator, Kubota, whatever, all the same regulator. The OE ones were flaky.

Here's the YM186 Wiring Diagram and the Regulator troubleshoot diagram.

If it were mine I would put an exhaust tip on the muffler aimed outward before it smokes up that beautiful paint.

You'll love the YM186D. Dismounting with the space so tight is the only flaw I can think of. Transmission whine in 3rd range like an old Jeep is apparently harmless. Aside from those two minor aspects its a flawless design.

I was out today towing a 2500 lb watering trailer up, down, across some significant slopes with mine. It's a real workhorse.

One comment - I mounted the rear wheels dished out, and external to the axle-end flanges. I think this extra width improves side slope safety.

 

[Johndeere3720]

I’ll have to mess with the alternator and see if it’s charging erratically or even at all. I picked up a 5ft finish mower on my way home last night and wanted to give the 186D a try. Initially it smoked bad so I pulled the fuel filter canister which looked to be spray painted over to find this gem of a filter. Swapped out the filter and drained / refilled the tank and bear instantly the smoke went away and it definitely seemed to gain some power. I did notice there’s a clicking sound when you push in the clutch after a pto implement is engaged. Is that an overrunning clutch?

 

[Smokeonthewater]

That filter's NOT purdy...

Re ORC... if you have one you can plainly see it on the pto shaft and if you turn it by hand you would hear the clicking...