ym146 noisy transmission..

[highpockets1]

Hey,thanks for the ad. Anybody have a YM146? I just bought one, checked it all out,listen to it run,drove it etc. took it home, unloaded it. But I did not stand behind it while it was running. next day went to hook a cart to it and the transaxle/transmission is making noise while running, in neutral. Cant really hear it when setting in the seat. please tell me it is just old and worn and yours does it too, instead of it is about to come unglued..thanks. I was really excited to get this,now I am a bit worried

 

[California]

That model has PowerShift? My present YM186D (next size larger), and my prior one, both Powershift, sound like sloppy loose clatter from the transmission when there's no load on the gears. Apparently not a problem.

Reports of any PS problem are extremely rare in this forum. Almost none.

Also, I hear gear whine in third range. Not as bad as an old Willys jeep but noticeable. Again, apparently not a problem.

I wouldn't worry about it.

 

[CoyPatton]

My experience from working on a few, are that many shuttle shift transmissions (yanmars power shift is closely related to these) have a whine similar to HST tractors. It seems this ‘rattle’ is worse at an idle. Possibly a condition of lower flow of fluid through the pump? I have never been in that part of the tranny so not really sure about that.
If you can have someone drive your tractor and walk behind it for a bit, if it settles down with movement or with an increase in throttle, I agree I would just verify the noise remains consistent and not worry with it!

 

[California]

Another peculiarity of Powershift is it seems to have a partial parking brake when no torque is exiting the transmission. It won't move when left on a slight slope the way a M/T will. Likely it needs its internal pump moving to release a clutch or band.

 

[highpockets1]

Thanks for the replies..yes..as soon as I move the shuttle/power shift into gear it quiets right down. kind of unnerving,keep waiting for something to come out the side of the case ! Thanks again for the replies and reassurance. This will prob not be my last question...

 

[rScotty]

I don't know a thing about the YM146 tractors...although I remember that they had powershift. At the time at US dealerships there was also a YM140/147 that was just a tiny amount larger physically, but had 4wd for a 50% increase in price. Most people were more interested in the YM147, but ended up buying the YM187.

The most common problem with older Yanmars with powershift is that the two suction filters have gotten clogged and are starving the hydraulic system. When that happens, the power shift internal clutches can't fully engage or disengage and they begin to rattle and eventually slip. There are two hydraulic filters in most Yanmar powershifts - one cleanable filter & one spin-on replaceable.

I wonder if the YM146 is anything like the YM140/147? The 140/147 both had those two filters like most other Yanmars. But on the 140/147 the cleanable filter was in a unique area on the rear end of the transmission/rear end back by the 3pt hitch. Look just to the left of the rear PTO output shaft. You are looking for about a 2" sized filter cover with a 1/2" NPT square headed pipe plug in the center of the cover. I think the cover has 2 bolts holding it on. You take off that cover to extact the cleanable filter. All the trans/hydraulic oil will of course pour out as the same time. So best to drain that first. The transhydraulic fluid drain plug is down and to the right of the cleanable filter cover. kind of back under the PTO output shaft.

At least all that is true of the YM140/147 Yanmars. I don't know if the same is where the filters are on the YM146 as well, but having those two hydraulic suction filters somewhere convenient is typical of powershift models.
luck,
rScotty

 

[CoyPatton]

I don't know a thing about the YM146 tractors...although I remember that they had powershift. At the time at US dealerships there was also a YM140/147 that was just a tiny amount larger physically, but had 4wd for a 50% increase in price. Most people were more interested in the YM147, but ended up buying the YM187.

The most common problem with older Yanmars with powershift is that the two suction filters have gotten clogged and are starving the hydraulic system. When that happens, the power shift internal clutches can't fully engage or disengage and they begin to rattle and eventually slip. There are two hydraulic filters in most Yanmar powershifts - one cleanable filter & one spin-on replaceable.

I wonder if the YM146 is anything like the YM140/147? The 140/147 both had those two filters like most other Yanmars. But on the 140/147 the cleanable filter was in a unique area on the rear end of the transmission/rear end back by the 3pt hitch. Look just to the left of the rear PTO output shaft. You are looking for about a 2" sized filter cover with a 1/2" NPT square headed pipe plug in the center of the cover. I think the cover has 2 bolts holding it on. You take off that cover to extact the cleanable filter. All the trans/hydraulic oil will of course pour out as the same time. So best to drain that first. The transhydraulic fluid drain plug is down and to the right of the cleanable filter cover. kind of back under the PTO output shaft.

At least all that is true of the YM140/147 Yanmars. I don't know if the same is where the filters are on the YM146 as well, but having those two hydraulic suction filters somewhere convenient is typical of powershift models.
luck,
rScotty

Good point rScotty! Again I did not mention filters, honestly did not even think of them, my bad for assuming maintenance has been done regularly. But any time we buy a new to us used tractor, just as you plan to change the oil and filter, fluid in front diff, we should also change hydraulic fluid, clean the suction screen and if equipped replace the spin on filter.