TC45DA sound on shutdown

[fishpick]

This is kinda a general knowledge question I have had since I got this great machine... when I turn the engine off as the tractor spins down - one of the last sounds from the left side - maybe - sounds a bit like the noise made when moving a straw up and down in the top of a SuperSized drink at a fast food place... kinda that ohhhh - uhhhhh-ohhhhh-uhhhh... it's NOT super loud... it is related to the RPM as the engine finishes it's last few turns before being done...
Dunno - just wondering.
Not an issue - not even a big deal... just other tractors don't do it and it's different... and I haven't been on here much lately and I figured... ehh - ask an odd question!

 

[Soundguy]

is it a belt noise? ( pulley noise? )

I sometimes hear squeaks at shutdown on cvarious machines depending on their belting, age and whatnot..

soundguy

 

[jinman]

I think what you are hearing is the hydraulic fluid surging through the HST cooler bypass. When you shut the tractor off, the HST charge pump surges a bit causing the bypass to also surge. It actually does the same thing when the tractor is cold and the idle is set to its lowest point. Some people have reported it as a clicking sound because the bypass has a ball checkvalve that opens and snaps shut, making the click. I bet if you held your hand on the top of the HST filter and shut off the engine, you'd feel it.

A remote possibility is that you have a small air leak where the muffler attaches to the exhaust pipe and it makes a noise as the engine shuts off.

 

[FULLPULL]

I was thinkin clogged air filter ?

 

[stonecomm]

Thats funny! My bike makes a very similar sound if Im hearing it right?:laughing: Havent studied it that close but the bike adds a bit of a whistle and I believe it is air traveling its normal path on the last stroke before motor stops.Good compression?

 

[fishpick]

@The Epic member of the Month - betls are tight... checked that b/c I thought maye it was a belt bearing that was wobbly or something...
@jin - I'll put my hand down there next time I shut her off... that does kinda sound like general location but NO WAY is it anywhere near a click.
Don't see any signs and don't hear anything when running to suggest that!
@FULL - new filter
@stone - great compression

Like I said - not worried... just a nifty little sound I was looking to understand.

 

[FULLPULL]

If i remember i took the rubber air inlet off of air filter housing to check a noise like your talking about and it went away on my old tc40. I put it back on and it only made the noise from time to time .I think this is it .