Chatter in neutral - 155D

[swedish-fish]

Yanmar experts/enthusiasts,
Several months ago I had a whirring/chatter noise coming from the clutch area of my YM155D (720hrs on meter but could well be more). It would occasionally chatter when idling in neutral and I was off the tractor (clutch pedal up). The noise went away when I depressed the clutch. Since then I split the tractor and replaced the friction disc, pressure plate, splined shaft, throw-out bearing and pilot bushing. Problem solved... at least until now. It recently started chattering again after only 15 hours since the new bearings/bushing. What gives? Has anyone else had this problem? I can't believe the pilot bushing would be worn already. The chatter/clatter is intermittant and goes away after the tractor is warmed up after a half hour or so.

If it's an option on this forum, I'll post a short mp3 audio file so you can hear the noise.

Thanks for your help.

 

[Gizmo36]

Don't know if yours is the same thing or not.But my son did one awhile back . It was find while it was hot out side .When it got cold weather it started to chatter till the tractor warmed up. He forgot to put grease in the u part of the throw-out bearing and on the shaft.I know it ant a u but that is the only way I know how to put it.The part that rides on the shaft in side of it.

 

[Travis_R]

My Mahindra 485 has been doing that ever since I can remember. I haven't worried about it. Right or wrong, I have been using it a long time with the chattering. Im not gonna do anything with it til something breaks/wears out. It hasn't give me any problems caused by the noise.

Travis R

 

[plowking]

Does the throw out bearing have a grease fitting like a big rig? I have seen the pilot bearing or bushing get damaged if transmission didn't go back in straight or was binding. My freightliner clutch rattles, but I spray the bushing in the helm joints on clutch linkage occassionally and the rattle goes away. If something has an interference fit and is loose, the heat from the engine could make the fit tighter and noise stops. plowking

 

[swedish-fish]

OK... you got me thinking.
I did originally put some grease on the shaft where the TO bearing slides, but not on the arms (sort of "U" shape) that contacts the casting that pushes the throw-out bearing. I'm going to try to attach some pictures I took when I had the tractor split...

Note the arms with the shinny surface. With a little patience, I could try to get some grease on those arms through the inspection port with the orange plug.

I've also included a closup of the old throw out bearing (no grease fitting) on the old shaft as well as the split tractor. Boy, that's a great way to get to know your tractor, but I'm not really looking forward to doing that again!

Someone else suggested adjusting the clutch for 1/2 - 3/4" free play. I've got a little more than that now.

 

[swedish-fish]

Ahha! adjusting the free play of the clutch pedal seemed to make the rattle go away. I reduced the free play down to about 3/4" of pedal motion. Also, for good measure I sprayed white lithium grease into the inspection port aiming for the arms that ride in the casting. It's 30 degrees out there now and once it started up I noticed no rattle even after letting it idle for about 15 minutes. At least I can sleep better knowing I won't have to split it again and that it's not damaging something.

Now bring on the snow!

 

[Gizmo36]

I used spray oil with Teflon

 

[Jagmandave]

Well done, swedish-fish! Glad you got it figured out. Hope you lubed the bushings that the throwout arm pivots on while you had it out as well. If not, a little spray lube there (if you can reach it) would be a good idea too.....