Broken front gears ym186d

[Swampfarming]

Today the front end of my ym186D had what i would consider a catastrophic failure.

I had it in 4x4 and it made a noise and i think i have something broken in the front end.

I parked her and removed the front driveshaft to find that if i try to move the tractor the front axle will turn about 1/2 turn and then tires will lock and drag.


The input shaft to the front axle seems to be disconnected from the differential.

When i lifted the front end off the ground i could spin as much as i wanted as long as the other wheel was turning the opposite direction, but when you try to turn them the same direction it locks up almost immediately.

I know i need to pull the input shaft and dig deeper but....

I have a line on a ym1510 parts tractor 4x4, could I unbolt my front end and install the front end from the 1510d? Since there aren't brakes and steering is very simple I'm thinking this would work but I haven't seen them side by side.

I was thinking this way i can keep my tractor 4x4 and dummy out my old front end to be 2wd and use the parts tractor as a mule.

Anyways please help !

 

[California]

Today the front end of my ym186D had what i would consider a catastrophic failure.

I had it in 4x4 and it made a noise and i think i have something broken in the front end.

I parked her and removed the front driveshaft to find that if i try to move the tractor the front axle will turn about 1/2 turn and then tires will lock and drag.


The input shaft to the front axle seems to be disconnected from the differential.

When i lifted the front end off the ground i could spin as much as i wanted as long as the other wheel was turning the opposite direction, but when you try to turn them the same direction it locks up almost immediately.

I know i need to pull the input shaft and dig deeper but....

I have a line on a ym1510 parts tractor 4x4, could I unbolt my front end and install the front end from the 1510d? Since there aren't brakes and steering is very simple I'm thinking this would work but I haven't seen them side by side.

I was thinking this way i can keep my tractor 4x4 and dummy out my old front end to be 2wd and use the parts tractor as a mule.

Anyways please help !

Ouch!

I know a little about this, likely just enough to mislead you. Hey Roger, Gary, what's the real solution?

I've read that the US YM186D had a different, stronger, front axle compared to the YM1510D that was its ancestor. Maybe a loader-rated axle.

Second, the YM186D parts book shows several different front and rear gear ratios depending on the size of tires available in the various countries where it was sold. So your chance of getting the right ratio in a 1510D > YM186D swap - is at best a 'maybe'.

But from your description there's a slight chance only the smaller differential gears are damaged so swapping internal parts might be sufficient, not the whole axle. If you never find parts then possibly reassemble as a 2x4.

I would start by seeing if any dealer can order OEM parts from Yanmar. Next, tractor junkyards.


Now you have me scared. I leave my YM186D in 4wd because this orchard is all soft ground and the shifter is extremely stiff.

 

[Harry in Ky]

The description sounds to me like the "smaller differential gears" are working fine, but the ring and pinion are more likely the problem. You stated the input shaft seems to be disconnected. Yet the whole assembly locks up when it tries to turn. To me that seems like some teeth have broke loose and are jammed up in the ring gear.

 

[Swampfarming]

The description sounds to me like the "smaller differential gears" are working fine, but the ring and pinion are more likely the problem. You stated the input shaft seems to be disconnected. Yet the whole assembly locks up when it tries to turn. To that seems like some teeth have broke loose and are jammed up in the ring gear.

This seems likely. I can hold the input shaft while I spin the front wheels.
I guess i will have to pull the front axle and disassemble to find out for sure.

 

[Gjamtrac]

This seems likely. I can hold the input shaft while I spin the front wheels.
I guess i will have to pull the front axle and disassemble to find out for sure.

I have attached pics of your YM186D front axle parts.
They may help you in determining the problem.
Sounds to me like Harry in KY may be correct.

 

[bmaverick]

This seems likely. I can hold the input shaft while I spin the front wheels.
I guess i will have to pull the front axle and disassemble to find out for sure.

There are 2 parts manuals available. The original and the updated one in 2009. Should you look for parts from Yanmar, best to use the 2009 edition.

If you find a parts tractor from salvage, then either edition should work.

YANMAR YM186 PARTS MANUAL 0CT10-G22801.pdf

YANMAR YM186 PARTS MANUAL 2009/12 0CT10-G22801.pdf

 

[careyo63]

I'm showing a Ym1610D and a YM1510D have the same Production Yrs. 79-81 15 Eng HP. to 16 Eng. Hp. the only difference. Today on Facebook market a complete Running 1610D is listed. 2000$ Asking

 

[Swampfarming]

There are 2 parts manuals available. The original and the updated one in 2009. Should you look for parts from Yanmar, best to use the 2009 edition.

If you find a parts tractor from salvage, then either edition should work.

YANMAR YM186 PARTS MANUAL 0CT10-G22801.pdf

YANMAR YM186 PARTS MANUAL 2009/12 0CT10-G22801.pdf

Does anyone have either of these parts manuals available currently? Or that I could download?

 

[rScotty]

Now you have me scared. I leave my YM186D in 4wd because this orchard is all soft ground and the shifter is extremely stiff.

California, we've discussed this a lot. Yanmars are designed as a 2wd with part time 4wd assist only when needed. Yanmars DO NOT have the center drive shaft differential that is required for full time all wheel drive. So...If the shifter is hard to get out of 4wd, then it shouldn't have been in 4wd in the first place. It is telling you that the tires can not slip enough on your ground to reduce the torsional load on the drive train.

I know you've operated yours that way for years, and don't know why yours hasn't broken.
It probably should have by now. Maybe your tires are very worn, or your soil hasn't much clay, or is a real damp mixture ....I don't know. Something is allowing it to slip. But I do know that using 4wd all the time is a good way to break a nice tractor.

If it is hard to shift out of 4wd, all the drive train is being stressed. With enough luck, stressing the drive train that way will eventually break something easily fixed. With even more good luck, that things that break will be the U-joints and splines on the front drive shaft rather than anything inside the front axle.

rScotty

 

[careyo63]

Maybe free. 0.00 marked down from 39.99 YM186 / YM186D YANMAR PARTS MANUAL *DOWNLOAD ONLY*

 

[rScotty]

The input shaft to the front axle seems to be disconnected from the differential.

When i lifted the front end off the ground i could spin as much as i wanted as long as the other wheel was turning the opposite direction, but when you try to turn them the same direction it locks up almost immediately.

Anyways please help !

That's normal for any differential. That is how they work.

 

[California]

California, we've discussed this a lot. Yanmars are designed as a 2wd with part time 4wd assist only when needed. Yanmars DO NOT have the center drive shaft differential that is required for full time all wheel drive.

rScotty

Thanks for the comments. This shifter is stiff, not due to binding but rather due to the shifter itself being stiff. With the front axle off the ground (loader bucket turned down then forced down) it takes enough force that I fear breaking the shift linkage, as I have seen others post here. I use 2wd where it's sufficient and when I go out on the un-paved easement.

The entire apple orchard gets disced so its so lumpy that you risk a twisted ankle walking around. And most everywhere is sloped. My experience is steering doesn't pull the nose around in 2wd, one brake is often needed to change direction in 2wd.

The first YM186D - without loader - that I had for a couple of years had the wrong, oversize, front tires and the spline on the input shaft (pinion) as well as the front driveline U-joint were damaged, as you predicted. No damage to the axle internals.

Before putting that tractor in service I bought the U-joint (rare, Honda ATV axle for just a couple of years) and had a machine shop drill and add two set screws. And got the right tires.


6.00 x 12 (the taller tire) and a 6-12 (the size Yanmar specifies for YM186D).

Typical use.

Anyhow - yes as everyone pointed out Swampfarming's observation sounds like a broken, jammed ring gear. And the issue now is how to find parts to repair it.

 

[Swampfarming]

That's normal for any differential. That is how they work.

Thanks for the comments. This shifter is stiff, not due to binding but rather due to the shifter itself being stiff. With the front axle off the ground (loader bucket turned down then forced down) it takes enough force that I fear breaking the shift linkage, as I have seen others post here. I use 2wd where it's sufficient and when I go out on the un-paved easement.

The entire apple orchard gets disced so its so lumpy that you risk a twisted ankle walking around. And most everywhere is sloped. My experience is steering doesn't pull the nose around in 2wd, one brake is often needed to change direction in 2wd.

The first YM186D - without loader - that I had for a couple of years had the wrong, oversize, front tires and the spline on the input shaft (pinion) as well as the front driveline U-joint were damaged, as you predicted. No damage to the axle internals.

Before putting that tractor in service I bought the U-joint (rare, Honda ATV axle for just a couple of years) and had a machine shop drill and add two set screws. And got the right tires.


6.00 x 12 (the taller tire) and a 6-12 (the size Yanmar specifies for YM186D).

Typical use.

Anyhow - yes as everyone pointed out Swampfarming's observation sounds like a broken, jammed ring gear. And the issue now is how to find parts to repair it.

Nailed it yes broken pinion and ring

 

[rScotty]

Thanks for the comments. This shifter is stiff, not due to binding but rather due to the shifter itself being stiff. With the front axle off the ground (loader bucket turned down then forced down) it takes enough force that I fear breaking the shift linkage, as I have seen others post here. I use 2wd where it's sufficient and when I go out on the un-paved easement.

The entire apple orchard gets disced so its so lumpy that you risk a twisted ankle walking around. And most everywhere is sloped. My experience is steering doesn't pull the nose around in 2wd, one brake is often needed to change direction in 2wd.

The first YM186D - without loader - that I had for a couple of years had the wrong, oversize, front tires and the spline on the input shaft (pinion) as well as the front driveline U-joint were damaged, as you predicted. No damage to the axle internals.

Before putting that tractor in service I bought the U-joint (rare, Honda ATV axle for just a couple of years) and had a machine shop drill and add two set screws. And got the right tires.


6.00 x 12 (the taller tire) and a 6-12 (the size Yanmar specifies for YM186D).

Typical use.

Anyhow - yes as everyone pointed out Swampfarming's observation sounds like a broken, jammed ring gear. And the issue now is how to find parts to repair it.

Good to hear. That's what I thought you had done, and I was surprised to hear that your 4wd shifter was stiff. Anyway, I'm glad that it is just stiff for some other reason, and not a result of four wheel driving.

As you say, lifting the front axle with the loader proves that it is not due to drivetrain windup.
I know you depend on that tractor a lot, and am amazed at the work it has done over the years.

BTW, I did end up doing some apple tree grafting this year. The donor is a roadside wild apple tree with unusually nice flavorful apples - A tree known to local people and the local bear populaition too. It's a dependably good producer on about a every other year cycle.

So last spring I cut some budded twigs from that tree and grafted them onto some of the non-productive mature wild apples on our place. To my surprise, all of the grafts took, grew, and leafed out. It's my first try, so grafting must be easier than I thought. I know it's not me, because I tried several different grafting techniques and they all worked.

Next step will be to see if those branches produce apples a few years from now.
rScotty

 

[bmaverick]

Does anyone have either of these parts manuals available currently? Or that I could download?

They are free on the YTOG