Yanmar Clutch

[millette]

Hello,

Has anyone here adjusted/replaced the hydraulic clutch pack in a yanmar tranny ? I have a 336D which has power slippage on the clutch. When I rev up the engine, it engages with weak power. At idle, the clutch does not engage.

I have the tractor split, and the main clutch is new (as you would expect with a power shift).

I have never gone that far into a transmission before.

I can see the hydro pump at the transmission end of the bell housing, but I am wondering if you can access the internal clutch by removing the cover place for the power shift input, on the TOP of the trans.

I don't like the idea of having to take the trans apart. Splitting it for the first time was enough fun. lol.

Thanks in advance for any kind of help anyone can offer.

 

[Normmm]

Before you take anything else apart chack the short shaft that connects the clutch to the powershift trans. This is a type of shearing device to protect the trans. Make sure that it has not sheared.

 

[millette]

Thanks for the advice.

Are you talking about the shaft that comes directly from the clutch (engine side) and goes to the splined coupler, and then into the what appears to be the hydro pump for the trans ?

There does not appear to be a shearing mechanism there. I don't think its a shear item, because the tranny does engage, just not at low RPM's.

I suspect that it might be a set of "clutch packs" or "disks" that are acting as a secondary hydraulic clutch for the power shift. Has anyone out there ever changed these clutch packs or disks ??

Any help would be appreciated. I am waiting for a parts/service manual to arrive, but talking to someone who has been through the process would certainly help.

Thanks in advance.

 

[roxynoodle]

You might want to check Hoye's website. He had the parts schematics online.

 

[Normmm]

I have not worked on the trans as you are doing. I based my comment on other posts on this forum. you might try a search of this forum for more information. I have read of more than one who has had a problem with something shearing in the input section to the powershift. Wish I could be of more help.

 

[1danny]

Hello,

Has anyone here adjusted/replaced the hydraulic clutch pack in a yanmar tranny ? I have a 336D which has power slippage on the clutch. When I rev up the engine, it engages with weak power. At idle, the clutch does not engage.

I have the tractor split, and the main clutch is new (as you would expect with a power shift).

I have never gone that far into a transmission before.

I can see the hydro pump at the transmission end of the bell housing, but I am wondering if you can access the internal clutch by removing the cover place for the power shift input, on the TOP of the tr

I don't like the idea of having to take the trans apart. Splitting it for the first time was enough fun. lol.

Thanks in advance for any kind of help anyone can offer.

The diagnosis tests are to be made before you split the tractor, as per Yanmar YM336D service manual.

Danny

 

[Jay1960]

I’m new doing this My 336d is doing the same. Had a new clutch put in a year ago and it was working fine till the other day Ikinda jammed it from reverse into forward. Today I changed filter and hydraulic fluid and still the same. It goes into gear but only when I increase rpm. Bucket hydraulics and power steering are working normally. Ps. I paid 6000 to have the clutch replaced. Thanks for any help. Jay

 

[bmaverick]

I paid 6000 to have the clutch replaced. Thanks for any help. Jay

what ... what ... what !

 

[winston1]

Not sure you are talking about the power shift clutch packs or the mechanical clutch. $6000 for either seems ridiculous. "If" you are talking about power shift problems I would first look at your relief valve springs in the regulator case. Do you have a parts manual and any kind of service manual? The parts manual is available on line and a 276 service manual is available on line which has trouble shooting section that would likely work for your 336.

 

[Gjamtrac]

I’m new doing this My 336d is doing the same. Had a new clutch put in a year ago and it was working fine till the other day Ikinda jammed it from reverse into forward. Today I changed filter and hydraulic fluid and still the same. It goes into gear but only when I increase rpm. Bucket hydraulics and power steering are working normally. Ps. I paid 6000 to have the clutch replaced. Thanks for any help. Jay

The PowerShift clutch packs do not require high pressure like the loader does.
They only need about 225 psi. And revving the engine really does not effect it. It puts out that much pressure at an idle.
The pump for the clutch packs is separate from the pump for the rest of the hydraulics. The pressure for the clutch packs is controlled by the springs Winston mentioned, which are in the Regulator Case on top of the transmission, under a sheet metal guard.
The springs are nos. 40 and 47 in the pic. Sometimes they just get weak and sometimes they break, but replace them both.
No. 51 is a filter screen which the early models had but later ones do not, if yours has one clean it and re-use it.