Hello Out There; last month I posted that my 2008 Kubota M7040/4wd,with 157 hours on it, was making a "clunking" noise at low idle. Can't hear the noise at 1,000rpm and above. Tractor runs great otherwise. No fluid leaks, no consumption of fluids except normal gas useage of course, plenty of power etc. Kubota is dancing around me (i.e.Dealer and Rep.) Another dealer says they ripped another 7040M open and couldn't find the problem with the same symptoms, that tractor is still operating o.k. 3 years according to them. Any suggestions as to the cause and how I should proceed. The tractor is still under warranty and the Kubota rep. says he'll give me a document that the tractor is o.k. even with the noise. I don't feel very good about this. What do you mechanical guru's think out there? Need some guidance. Thanks; Great Site: Nico in Upstate PA.
Kubota M7040 "clunking noise"@idle
- Thread starter NICOT
- Start date
Thomas
Epic Contributor
- Joined
- Apr 6, 2000
- Messages
- 29,792
- Location
- Lebanon,NH.
- Tractor
- Kubota B2650HSD w/Frontloader & CC LTX1046 & Craftman T2200 lawn mower.
Where do you think noise coming from..motor of tranny?
Good move to keep dealer updated.
Good move to keep dealer updated.
leonz
Super Member
Ouch;
The first thing I can think of is a hydraulic accumulator charging and discharging.
The second thing is a relief valve opening and closing with fluid surges as the hydraulic oil is being pumped at low idle and is running through the hydraulic system.
if the relief pressure is set to low it will open and close constantly.
How much hydraulic oil do you have in the tractor when its shut down overnight and cold?
I would ask them to check the hydraulic system pressure and the relief setting which should be checked when the oil is hot and above 140 degrees.
Thanks guys; Relative to my Kubota 7040 M, it sounds like the "intermittant clunking" noise is coming from above or at the engine under the front hood. You can't hear it at higher idles and when the tractor is moving or throttled.
Very annoying.
As far as the hydraulic oil, I will check it, but at last check the oil was up to the right level. Do you'all feel this noise indicates any major problems? Kubota is not being very helpful on this one. Thanks; Nico in the endless mountains of PA...
Very annoying.
As far as the hydraulic oil, I will check it, but at last check the oil was up to the right level. Do you'all feel this noise indicates any major problems? Kubota is not being very helpful on this one. Thanks; Nico in the endless mountains of PA...
E/S
Gold Member
I just went through a problem with my M8540, couldn't duplicate / get it to act up on command. Finally found the problem and they fixed it.
The also extend part of my warranty, it wouldn't hurt to ask them to do that for you ( since they are so sure there is no problem ).
E/S
The also extend part of my warranty, it wouldn't hurt to ask them to do that for you ( since they are so sure there is no problem ).
E/S
Thanks for the response NV. Your tractor looks nice. The Dealer is really weak. The rep. is supposed to come out to look at the 7040M with the intermittant "clunking noise" at idle. He says if I feel the hydraulic lines up towards the top of the engine, when the "clunk noise" comes, you probably can feel the hydraulics pulsing. He says it's air in the hydraulic lines. There are no leaks, but he says they have to take the fenders off and replace a rubber gasket of some kind, yet he still says it's no problem and they did it for another 7040 M and the noise kept up. That 7040 M is still running fine according to him. Maybe the Kubota Rep. will extend the warranty. Thanks for the suggestion, NICO in "gas land" N/E PA.
E/S
Gold Member
Keep a good sense of humor and get the rep. out there.
They spent 5 hrs on mine and I couldn't duplicate the problem for the first 3 1/2. When it did fail the rep. knew right away what it was, they ran some more tests and ordered parts.
Good Luck
E/S
They spent 5 hrs on mine and I couldn't duplicate the problem for the first 3 1/2. When it did fail the rep. knew right away what it was, they ran some more tests and ordered parts.
Good Luck
E/S
rjkobbeman
Platinum Member
What was the problem?
Glad to see, your on your way to fixing it. Actually, curious as to what it was with your rig? Thanks NV, Any other takers as to what it may be; this "clunking noise" at low idle on the 7040M. My sense of humor is waning, especially when I think of what I paid for the piece. NICOT, hoping the orange is o.k. in the hills of PA!
leonz
Super Member
FWIW
you do not have to leaks to have air entering the system.
One section of the pump could be going bad and possibly have a bad pocket seal
or a missing gear tooth in one of the gear sets and create a lot of turbulance.
If there is air in the hydraulic oil the oil would be foamy all the time and the tractors hydraulics would be very erratic. Does this machine have a loader on it?
If the tractor has mounted equipment like a loader it would be easier to diagnose as the controls would be spongy and erratic.
I am very surprised the oil does not look like milk in the sight glass.
You obviously have entrained air in the oil and it is compressing and expanding
If they have replaced the rubber suction hose from the oil tank to the pump it would explain a lot for sure.