Kubota M4 Utility Tractor Transmission Whine

[5030]

I cannot get a 'code'. Nothing to generate one. 100% mechanical injection and no emissions junk to fail but my one units still whines anyway. Least it's the cab unit so I can close the door.

Interestingly. it also has developed an issue with the fuel cut solenoid and is at the dealer. It's 18 years old and my dealer is having a hard time diagnosing the issue and has gotten Kubota involved. He installed a new fuel cut solenoid, made no difference. He told me that even at 18 years old, Kubota will stand good for whatever it is. I'm thinking there is a feedback coming from the glo plug controller but I'll leave that up to Kubota. It's in for it's 1500 hour valve adjustment anyway. Kind of went past the 1500 hour adjustment by 200 hours.

 

[Borane4]

What an irritating noise. A lot of people it seems have that problem, but not all. I have the M4-071 (not D, so my 4WD is a manual lever) and I have not experienced the whine...yet. In most of what Ive read no one has found a solution. It certainly seems to be damaging the reputation of the M4 though.

 

[JP_Austin]

So I have less than 20 hours on my new M4D and yes it makes the same whine while hot and in 4WD or when the brakes are touched. Initially I thought it was a loose belt as it comes from up front near the radiator. I think it's a bypass valve that is kicking on and allowing hydraulic fluid to pass. I have no issue when cool or even if I engage then turn off the 4WD switch it will go away. I did at first have a belt squeal when first starting but I tightened the alternator a touch and that went away.

Certainly has to be warm. I noticed it while I was running a bat wing mower and working the unit fairly hard. After about 20 minutes I slowed down and stopped to move some debris in front of me when I noticed it and seems to corellate with the 4WD button and the brakes. I believe the front wheels are engaged into 4WD while the brakes are engaged to safely slow down and maneuver. That would imply it's the engagement of the 4WD system that is causing this issue.

 

[JP_Austin]

I ordered the M4D service manual so I can at least understand how the 4WD engages and is in play while braking. Hope it arrives this week so I can dig a bit deeper. As others have stated the dealers are clueless with this noise.

 

[5030]

So I actually got a full engine warning code that popped two weekends ago after I had it parked and it whined the whole time. I shut it down and did a restart and the code went away but it got me a little nervous knowing I'm heading into hay season.

Time to buy a a second unit like I have. Just don't tell the wife until after you do the deed.

 

[sea2summit]

Time to buy a a second unit like I have. Just don't tell the wife until after you do the deed.

I've seen only three tractors in the 80+ HP range go by since Christmas that I would consider, one was as old as my dad. I saw one M9000 popup two weeks ago and I think it sold in the first day. I've got to look at taxes this year due to some special circumstances, if I'm going to jump to a larger tractor it may be the time even though the M4 is barely broken in.

 

[sea2summit]

I ordered the M4D service manual so I can at least understand how the 4WD engages and is in play while braking. Hope it arrives this week so I can dig a bit deeper. As others have stated the dealers are clueless with this noise.

Not much there, for trouble shooting your choices are add fluid or split the tractor so small wonder the dealers don’t want to touch it.

 

[5030]

No fix yet. Kubota region manager told me the Kubota engineers are still working on a fix for it. The engineers so far do not see an issue with the whine being there or affecting anything, unfortunately it is an annoying sound. Kubota did state they will cover the transmission even if the tractor goes out of warranty which will be in this September.

They are pretty good about that stuff unlike some of the other manufacturers. I'm having an issue with my 2004 M9 that my dealer's shop cannot figure out so they got Kubota involved and when I talked to m (owner) last week. He indicated that Kubota would pay for at least a portion of the repair. Keep in mind this is a 2004 tractor with 1700 hours on it. Kubota never ceases to amaze me.

 

[5030]

One thing I don't like about Kubota is they bury the wet packs in the gearbox and the only way to access them is by splitting. On my M's, I can see the pto pack no problem but I cannot even touch it. It's forward of the rear axle ring and pinion. Cannot even see the travelling pack at all.

At least splitting them isn't too involved as there is no clutch to deal with in the bellhousing. Just a splined damper plate.

Never had an issue with either but renewing or replacing either entails a split.

I'd sell you one of my M9's but I need them both, why I bought 2 in the first place.

Besides, every time I check pricing, the increase in value.

 

[JP_Austin]

Not much there, for trouble shooting your choices are add fluid or split the tractor so small wonder the dealers don’t want to touch it.
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Thanks. Looks like there is a bypass regulator along with test ports. I’ll snoop around and see if it’s the noise maker. Wondering if the fluid expansion at high temps is increasing pressures higher than spec.

What’s interesting is they rely upon the 2WD solenoid to be activated to disable 4WD. The 4WD has a large spring to engage and appears to be the default. So if it were a faulty solenoid it should default to 4WD full time.

Given that scenario I’m suspecting the fluid pressure is excessive and that bypass is bleeding off the excess. Tractors with more hours may not show the issue if they leak down or settle in with lower pressures over time. At least a theory.