kubota 2007 B7800 4x4 tranny makes a loud winning noise when speeded up . hydro tra

[ohiojim]

going down the road .top speed the tranny wines loud ,back off and the noise stops . start going fast again it starts. sounds like a relief valve or something . question? easy fix?? how ?? . I.m handy and the kubota shop is booked two months out. noise sounds like its coming from mid tractor area. any help appre .

 

[JOHNTHOMAS]

Did it just start doing this after 6 years? If you just bought the tractor the HST in high gear at high speed has a normal whine especially noticeable on a paved road.

 

[ronjhall]

All the tractors in this size that I have driven. Have a wine in H gear.

 

[ScottyChip]

That would have been my question as well. Did the noise just start? Has something changed recently? I have a B7510 and just after I purchased it I felt the same way about the noise from the machine in high gear. The dealer looked at and no issues found, but I was still concerned. Searched this site and most owners noticed same noise, turns out normal. Looked at a number of videos with the B7800, and listen to the tranny, and compare. Just my two cents,(well that is what I would say if we still had cents in Canada).

 

[Mendonsy]

My B7500 will do that if it is in 4wd, but the noise goes away in 2wd.
I suspect there is a slight difference between the front to rear gear ratios and the tire diameters.

 

[jeff9366]

I specified Kubota SUDT2 at my 350 hour HST hydraulic fluid change. SUDT2 reduced high frequency wine more than half. Not total noise, just high frequency whine, which i found awfully annoying and gave me a headache.

Whine reduction seems to be mainly in HST transmissions, young and old, according to T-B-N posts.

 

[ohiojim]

this noise just started and its LOUD , not just a annoying whine, tractor even slows down , stop movement and start going again it dis appears but will come back if you speed up. tractor bought new no other problem, I still think its a relief valve not holding the proper presure,

 

[BeezFun]

If you have a video camera can you record a start and stop cycle? It would help a lot to actually hear the noise come and go. I have a B2710 which is very similar to a B7800 and it whines like a teenager in high gear, but the noise steadily gets louder and softer with speed, there is no sharp increase in sound as you reach top speed.

 

[rswyan]

Scope out the plastic cover for the driveshaft going to the front axle ... try loosening the clamp that holds it and rotate it to a different orientation, then retighten the clamp.

Makes the loud noise on my B2910 magically disappear ...

 

[oldballs]

I'm a newbie, but why would one drive in 4 x 4 when just cruising down the road? Or does it really make any differance?