Loud chrip from the front end when moving, goes away with 4wd engaged- B2620

[jaymoney2]

Hello! Trying to diagnose a loud chirping noise from the front end of my B2620. I only hear it when driving in 2wd. As soon as I engage 4wd and start driving again, the sound goes away.

Was thinking a bearing may be going somewhere along the front drive train, and the added pressures/ torque from 4wd make its go away (similar to when a wheel bearing makes noise only when you make a high-speed turn).

Cant seem to get a noise when manually rotating tires.

I am not opposed to replacing bearings to see what clears it up, but there are quite a few in the parts diagrams, and that could get expensive quickly!

Any thoughts on what could be causing the noise, or tests I can perform to pin-point or eliminate certain bearings?

Thanks in advance!

 

[xrocketengineer]

Any oil in the front axle?

 

[jaymoney2]

Any oil in the front axle?

There is fresh gear oil in there now, it was low when I bought it (with 450 hours on it) and noticed the chirp before replacing the oil. Now having a leak, so planning a seal change.

with that being said, it is possible that it was run low on gear oil, especially on the top end where the driveshaft comes in.

the chirp hasn’t resolved since replacing / fully filling the gear oil.

 

[ruger1980]

where in the front end does it seem to be coming from? Out by the wheels or near the differential? Can you post a video or audio clip of the noise?

 

[xrocketengineer]

If the differential is the highest point, maybe the bearings ran dry and are no good any more.

 

[jaymoney2]

where in the front end does it seem to be coming from? Out by the wheels or near the differential? Can you post a video or audio clip of the noise?

no luck getting a good recording of the sound, but I was able to get under the tractor without the parking brake on, and rock it back and forth (just the play within the drivetrain) and it actually sounds like it’s coming from the bend in the front drive shaft. It has a plastic housing around it. assuming there is a U-joint in there...

 

[RCW]

Jay - get some parts diagrams here.

Should help with how it all hooks together:

Kubota Tractor Corporation - Illustrated Parts List

- K-PAD - Parts Lists - Illustrated Parts Lists - diagrams

apps.kubotausa.com

 

[Donystoy]

My first thought was also a universal joint. I had a similar scenario with my B7200 a few years ago. Turned out to be the rear universal at the hydro case.

 

[marrmanu]

I have a B2620 it would be good to know what you find out. Hope its not to big of a issue.