Intermittent squeal at high speed

[Bellinghamster]

I finally got the D950 up and running in my B7100D-T... I had to make some pretty creative coolant piping adapation (it was a thermosiphon D750, now a waterpumped D950, but still using the old radiator), but it's hooked up and working. Re-filled all fluids and assembled enough to run it around. I still need to machine a front PTO shaft adapter to bolt to the front pulley to run my FEL pump, but it was feeling like this project was wrapping up.

The next challenge may have already presented itself. When running along flat ground at high speed (high 3rd gear at more than half throttle in 2wd) there is an occasional/intermittent squealing that sounds like it's coming from the front of tunnel between the bellhousing and the gearbox. First though was the throw-out bearing, but it makes no difference if the clutch all the way out or with light pressure on the pedal. It sounds like a dry bearing kind of noise.

Maybe a failing bearing for the front driveshaft? Are the bearings in the tunnel lubed by the transmission/hydraulic oil?

Any thoughts or advice?

 

[deltacharlie]

Hi,
Just read your post as I have exactly the same problem. My problem occurred after I fitted a new clutch plate. One year later, I still have the same problem so split the tractor today to see if it was the clutch release bearing. (throw out bearing). It looks OK to me, not rough or dry so I am wondering maybe it is something else. Before fitting the new clutch plate there was no noise. I can get the noise to show in all gears high rpm, but it comes on quicker in third. It is still the original release bearing. Any one any ideas?
Regards,
Dennis

 

[Bellinghamster]

I'm kicking myself for not inspecting/replacing the clutch release / prop shaft bearings when I had it split. I think I'd better get the squeal figured out and fixed before remounting the FEL subframe, as that about doubles the amount of work to get back in there again.

 

[uncle jed]

there's a possibility the pilot bearing or bushing may be causing the squeal .. uncle jed

 

[Bellinghamster]

Nope. Brand new pilot bushing, plus the transmission input shaft only turns in the pilot bushing when the clutch is disengaged. When the clutch is engaged the crank/flywheel and input shaft all rotate as one.

 

[Bellinghamster]

I found a couple threads discussing what sounds like the same issue: http://www.tractorbynet.com/forums/...75-noise-question-may-not-transmission-2.html
and
http://www.tractorbynet.com/forums/kubota-owning-operating/115836-b7610-squealing-noise-2.html

I had the front driveshaft disconnected when I split the tractor. It sounds like it's rather common for the rubber boot to be misaligned allowing the shaft cover to rub on the front driveshaft, causing a dry bearing noise at high-speed. That'd sure be a nice and easy fix! The location makes sense from where it sounds like the noise was coming from. With fingers crossed, I'm heading for the greasegun!

 

[deltacharlie]

You are in the right area. I have just jacked my B7100 up on one side so that both wheels on one side are free to rotate. This is dangerous so don't do this. I then started the tractor up, engaged 4wd and top gear. Opened the throttle to mid range till the squealing started. Felt the propshaft cover and this was where the vibrating is coming from. By moving the propshaft cover I could get the noise to start and stop on command. Bingo!
Stopped the engine and had a look underneath, the cover had a felt washer pushed back when the tractor was split and didn't go back when re-assembled. Thing is the Uj's don't feel too good so I am thinking it might be dry uj or just the propshaft rubbing on the cover - either way it is all doable from the outside. Still pondering what to do next. The manual I have of the prop group is not clear, any one have a clear image of it?
I don't recommend anyone doing the above check though, as it really is dangerous and stupid.
Regards,
Dennis

 

[deltacharlie]

I finally got to the root cause of my squealing. I slid the rubber boot back on the prop shaft and laced it in grease as previous posters have recommended. Tested, squealed like a pig!

I then squirted some WD40 at the TOP of the tube nearest to the UJ's where the felt washer (oil seal) is. I also squirted the UJ's whilst I was there. Extensive testing now reveals a QUIET TRACTOR once again.

Conclusion. I think it was the felt washer (I think it is felt, it is pretty dirty down there and access is very limited) that was disturbed that caused my problems. The dry felt rubbing on the prop shaft at high rpm caused the vibration that set the prop shaft cover squealing. A liberal dose of WD40 silenced it. Next time I get under I will squirt some grease around there.

To think I have put up with this squealing for a year when all it wanted was a touch of lubrication. Is there anything WD40 can't fix?
Regards,
Dennis

 

[Greg]

Glad to hear it was a simple fix. We must always listen to our equipment,more times than not, it is telling us what to do.

 

[Bellinghamster]

That's fantastic news! I was dreading having to say (again) "honey, I need to spend $xxx more before I can actually USE the tractor... that line is getting pretty worn out!

I was planning to jack up and run in place this weekend... but I'd planned on using 4 jack stands so all wheels were free to spin and less likely to take off across the shop! There's a terrible visual for ya with nothing possible but a bad ending.

I found that the online parts manuals (Messics, for example) to be clearer-when-zoomed than the PDF version I've got downloaded. My B series WSM doesn't describe or show how to get in there other than as part of a major teardown. I suspect the tube can be pulled out if the front axle is dropped first. From the parts diagram it looks like there should be a bushing in the tube, but it's not clear if it should be at the top or bottom end of the tube... it goes in from the top, and I guess stops where it should.

 

[deltacharlie]

My drawing isn't clear and I also looked at Messicks version which is a little clearer. The bushing (oil seal) goes in at the top. At the bottom it is the rubber boot that provides separation and mine had taken on a warp but no way can it touch the propshaft. Try what I did first. Have a look at the prop shaft cover to see if you displaced the oil seal when you slid it up to disconnect the prop shaft. Put it back in place if you did, I used a screwdriver to just slide it back. Squirt some lube first so it slides easier, probably best to use grease. I then squirted the UJ's just for good measure and enjoy a quiet tractor at whatever rpm you choose. I wouldn't like to say 100% whether it is the UJ's or the dry oil seal that sets the prop shaft cover vibrating, all I know is mine doesn't any more.

My UJ's are not 100% (tractor has over 2000 hrs on the clock) and are loose on the spline where they mate with the propshaft. Long term they need some attention but OK for now. This has been a real head scratching fault for me, but so satisfying when it is cured. Please let us know how you get on. It does seem to be a re-curring problem for the oranges.

Regards,
Dennis