Knocking noise from rearend while in high range of transmission on 2005 kubota l3400

[okibarn]

My kubota l3400 has a knocking noise from the rear while in high range of the transmission, it started within the first six months of use and when it started it was very low, now it is quite loud and increases with speed. It sounds as if a bolt is hitting something inside the rearend with every revolution.

 

[PapaPerk]

My kubota l3400 has a knocking noise from the rear while in high range of the transmission, it started within the first six months of use and when it started it was very low, now it is quite loud and increases with speed. It sounds as if a bolt is hitting something inside the rearend with every revolution.

Under warranty? Take to dealer.

 

[Leejohn]

Check your lug bolts 1st.

 

[s219]

Check your lug bolts 1st.

My thoughts exactly.

 

[Diesel breath]

I get a knocking noise from my rear end from time to time too! I think it's from the taco truck though.

 

[Oldpath05]

I'm searching the web about a similar, knocking/snapping/ticking, problem if not the same, on my (07) L3400 DT. I now have 600 hrs. on it, but I notice the noise most in low range while the diff. is lock in, the snapping noise seams to be coming from the left rear side, and so far it doesn't do it all the time, yet. I probably wont find the problem or exactly where the snapping noise is coming from until it goes BANG, and the rear wheels wont turn.

 

[KennyV]

I'm searching the web about a similar, knocking/snapping/ticking, problem if not the same, on my (07) L3400 DT. I now have 600 hrs. on it, but I notice the noise most in low range while the diff. is lock in, the snapping noise seams to be coming from the left rear side, and so far it doesn't do it all the time, yet. I probably wont find the problem or exactly where the snapping noise is coming from until it goes BANG, and the rear wheels wont turn.

Check ALL the bolts that mount the Wheel ... the left side generally will loosen and give you that sound when Any of the wheel bolts lug nuts are loose... KennyV

 

[Oldpath05]

The wheel nuts/bolts seam to be tight, it does sound like that kind of noise though. If it would make the noise all the time, it might be easier to locate. I have notice that the diff. lock petal squashes down about 1/4" more at times, but if the snapping noise is coming from inside the transmission, then it should do it all the time, also, I don't even know it a transmission will make that kind of sound. I do know it's a sound that no one want's to here if they cant afford another tractor.

 

[Recoveryhill]

Lug nuts/bolts need to be torqued to factory specification, not seem to be tight. That said, the potential for a catastrophic failure would seem to indicate that you go to the expense of having a dealer or an experienced mechanic take a look. Even if it's out of warranty, which I assume, the cost of diagnostics now would be far less than the cost of a serious failure of your running gear. Listening to something like that and worrying and wondering won't do. It is also the type of symptom that is near impossible for anyone not up close and personal to your machine to diagnose. I agree that lug nuts were a good place to start.

Also...I don't know if I've ever had my tractor in high range. Then again I don't do road transport of my machine. At the very least, if your knocking is only in high range, stay out of high range?

Also...For less than $40 you could have samples of both your engine oil and transmission fluid tested by a lab, I use Blackstone, for substances that shouldn't be present in a healthy machine. If you have metals above expected limits, what metal and where it is present would give you somewhere to start.

 

[rbargeron]

..... the potential for a catastrophic failure would indicate that you ......have an experienced mechanic take a look.....the cost..would be far less than the cost of a serious failure...........worrying and wondering won't do........... near impossible for anyone not up close to diagnose...............

True words all.

 

[JMER817]

Check your front axle thrust bolt. I had a clunk sound coming from my JD and swore it was coming from the rear axle.

 

[Oldpath05]

I looked up the L3400 rear wheel torque, 160 ft-lbs. pounds. My 1/2" drive don't go that high, guess I have to look for a 3/4 drive torque wrench somewhere. I'm almost certain if I call up Union Farm Equipment to come get the tractor, they'll drive it around, and say we didn't here no snapping noise, and say it's find, here's the $200.00 bill, thank you and come again, and that's the problem with a noise that's not constant, only happens once and a while. I think the only way of finding this snapping noise problem is if a mechanic has heard of that kind of sound before, and knows rite where to look. A wise man once said, "If it ain't broke, you're not trying"

 

[Oldpath05]

Check your front axle thrust bolt. I had a clunk sound coming from my JD and swore it was coming from the rear axle.

Never heard of this bolt. I'll have to look in my manual with the lousy pictures and see if I can find that bolt, the only clue I have is, it sounds like it's on the front end.

 

[JMER817]

Never heard of this bolt. I'll have to look in my manual with the lousy pictures and see if I can find that bolt, the only clue I have is, it sounds like it's on the front end.

Ever figure out what it was?

 

[Oldpath05]

Only heard it a couple times since, so it's hard to pin point still, someone mentioned it might be a wheel bearing. I had bearings before make part time noises before on cars. I didn't haul any logs out this past weekend, so at this rate, this clicking noise could go on for a couple years. I spent an hour in my manual with the lousy pictures, and couldn't find the thrust bolt on the front end, maybe the L3400 doesn't have one.