B7800 making noise in high gear only!

[Cajun_MD]

I have a B7800 HST 4x4 with about 120 hours. We use it manly for mowing 4 acres. Yesterday it started making a noise when moving in high gear. It's hard to describe the noise. It's not grinding or crunching. It kind of sounds like the cartoon Jetson's car. Switched to medium and low and nothing. The noise is louder when going full speed and goes down when the speed goes down (or as I let up on the pedal). It seems like a pump issue, but I don't know. The performance is not affected. It still pulls and mows flawlessly just a funny noise when in high gear travelling to different areas. Thanks in advance for your help.

Craig

 

[MarkLeininger]

Did you accidentally engage one of the PTOs that you don't normally use?

 

[Greenfield Dave]

Sounds like it's in 4wd to me...

 

[Barnboy]

There has been some problems with a rubber boot on the front drive shaft that comes loose causing gear grinding noise ect ect. The noise will get louder with speed. I had this issue with my B3030 and another TBN member. Look close. It dont look like its the culprit but my guess it is. Look here see if this sounds like yours http://www.tractorbynet.com/forums/kubota-owning-operating/115836-b7610-squealing-noise.html

 

[Cajun_MD]

That sounds exactly like what I am experiencing. I really couldn't describe the noise, but you guys nailed it. Thank you very much for the info. That is a very quick fix. I knew it couldn't be much.