Buying Advice Need some help buying my first Yanmar

WillyH · Jul 5, 2017

Hi everyone- a YM135D sort of fell into my lap yesterday, and I'm in the process of evaluating it. I'm told that it needs a clutch, so I'm getting ready to order parts. The tractor was originally sold by Gary Jamieson, who's up the road from me a bit, and I spoke with him a little today. I wasn't able to name the PO, so we spoke in general terms about 135s, and he of course confirmed much of what I've learned reading this forum recently. He told me that a transmission problem is very rare in this model, but I worry about the noise that I'm hearing. Let me describe what I've observed.

Trans oil is low- about 1/4" on the dipstick. Clean and clear from what I can see. Hitch lift arms lift 230 lb easily. No noise from hydraulics. Aux hyd cylinder works properly.

1) Clutch pedal feels ok, like it's operating the release bearing and the pressure plate correctly. Pedal has ~3/4" free play, which, per Gary, is correct.

2) Engine running, trans in neutral, PTO in neutral = no noise to speak of.

3) Clutch pedal depressed, trans put into any gear = no noise.

4) Trans in gear, clutch pedal released = instant and constant gear mesh noise from forward section of trans. Tractor makes no attempt to move, no effect on engine speed.

5) Clutch depressed, trans in neutral, PTO set to either speed = no noise

6) PTO in either speed, clutch released, same gear mesh noise as above. PTO will spin listlessly, can be stopped with no effort, no effect on engine speed.

So it seems to me that there's no torque whatsoever being transmitted by the clutch, but then there's all this gear mesh noise. It really sounds like gears, not a bearing, and it sounds like its under the shifter, not in the bellhousing. Of course, I could be wrong. I'll try to add a little video below.

IMG 9496 - YouTube

I'll try to embed the vid when I figure out how.

Is there anything like a key that can shear on the output side of the trans? If there is such a thing, would it include the PTO? It sounds to me like there is input to the trans, and things are spinning inside the gearbox, and they they are engaged and disengaged by the clutch, but there's no output.

Thoughts? And Thanks.

kwanwon · Jul 5, 2017

I have the same tractor and I would ask Hoye Tractor, they are very helpful and a great place to purchase your Yanmar parts.

winston1 · Jul 6, 2017

I would suspicion this. SPLINED COUPLER - NEW In Stock!!: Yanmar Tractor Parts

WillyH · Jul 6, 2017

Winston, that is the part I began to suspect shortly after posting last night. Glad to have your input, thanks. The fact that the tractor has the dozer blade on it sort of adds weight to the diagnosis. Thanks again.

void777 · Jul 6, 2017

WillyH Welcome to TBN winston1 I belive your right sound like a coupler to me too.

rScotty · Jul 6, 2017

Do you have an exploded diagram of the transmission? Workshop manual or a good parts picture? Those old small gear drive Yanmars were all much the same.
For the next step I'd probably drain the oil, remove the tubular cleanable transmission oil filter (on the right side on most), and perhaps lift the shifting cover and look around inside.

And then get set up to open the transmission. It sounds like you have what is basically a good machine. Well worth the effort to fix it.
luck, rScotty

winston1 · Jul 6, 2017

If it is the coupling it will be in the clutch (bell) housing.

WillyH · Jul 6, 2017

Glad to hear it. I've decided that splitting the tractor is the logical thing to do, while it's at work and near my toolbox. I'll have a look at the clutch and bearing, replace the coupler, and poke around in the trans while cleaning the screen and changing fluid. I'm looking forward to getting to know this little guy. I'd been hoping that a green Yanmer would fall out of the sky and hit me in the head, and that's pretty much what happened with this one. Thanks for the input, I'll keep you posted as I go along. This place is a valuable resource, filled with friendly people. I'm pleased to be among y'all.