Transmission noise?

[genelp]

I just got my tractor back from the shop today. My wife started it up to mow and we both immediately noticed the tractor was making a noise that sounded like a vibration. I have bad hearing, so I had my wife listen and try to pinpoint the area the noise was coming from. It looked like it may be coming from the area behind the engine. I pushed in on the clutch and the noise disappeared. When at idle speed sometimes there is a noise and sometimes not. When I raise the engine RPM the noise/vibration starts in. As I stated I have bad hearing so I don't know for sure what it actually sounds like, but my wife thinks its a vibration (a very loud one).

I just received it back from the shop, but I can't see how the repairs they performed on the tractor could be related to this noise. They repaired an electrical problem and aligned the front axle.

I almost forgot to mention that the tractor is a B1750 with a hydrostat transmission.

Any ideas or advice would be appreciated!!

Thanks

Gene

 

[kubmech]

There are a couple of things that will cause that noise on that model. One is the clutch splines tend to wear out on them which is fairly common, but usually the noise will get worse when the clutch is pushed in. The other possibility is that the drive shaft coupler is worn and dry. The coupler is made up of 4 ball bearings inside, that seat in a groove which allows it some movement out side the plane. Over a period of time the grease drys up and they begin to wear causing the noise you hear. Another possibility is that the pin that attaches the coupler to the hydro input shaft has broke or fell out and the drive shaft is moving forward and aft. It does not sound to me like anything the shop did has caused this problem. If it is a noisey coupler they may not have mentioned it, due to it being fairly common. If it is truly "very loud" I would check into it more.

 

[genelp]

Thank you, your advice is always appreciated! I'm going to look at the drive shaft coupler today. I assume that I can access it by removing the cover over the transmission filter.

Thanks,

Gene

 

[kubmech]

I think you can get to it by removing the cover. If I remember right there should be another panel under that one you can remove and get to the drive shaft and see if it has any excess movement. If that does'nt provide enough access removing the mower deck will get you a better view.