B2920 "arroooogahh" Sound

mswlogo · Nov 23, 2014

Try engaging the PTO when it's making the noise.

It might be it's partly enaged with no load.

Dan W · Nov 23, 2014

mswlogo said:
Try engaging the PTO when it's making the noise.

It might be it's partly enaged with no load.

Mswlogo, I tried that several times, the PTO is definitely out...
Dan

Dan W · Nov 23, 2014

rswyan said:
Someone has (me) ... it's the shaft cover.

OK, just got background looking under the tractor.
There are 2 shaft covers one for the front driveshaft and one for the rear.
Rswyan, which Shaft cover did you remove or determine was vibrating?
Now I'm wondering if the vibration or growling sound is actually being caused by one of the 2 u-joints having failed or centre support bearing failure. This is definitely related to travel speed, with 4 wheel drive engaged or not. Could either the front driveshaft or the rear one be so floppy to actually be hitting one of the covers...this sounds like this is the answer... Thanks Rswyan, I'll take this apart again...
Dan

Leejohn · Nov 23, 2014

I have my B7800 in my shop right now getting ready to take apart just for the reason you gays are talking about. This has been going on for 3 years it's time to stop it. What I have done is back up a few feet and go again, sometimes it wouldn't do it until the next time I used it.
After reading what rswyan has said I'm going there. With it not doing it all the time and I can backup it might be shifting the boot back into place.

mhart · Nov 23, 2014

Thanks guys let me know what you find out. Thanks to rswyan much appreciated. When I looked at the plastic cover, it was clamped down tight against the fattest part of the driveshaft. Is that the proper orientation? Perhaps someone could post a shot of what it is supposed to look like when positioned properly. I unclamped it, rotated it around and then clamped it back. Not sure what I accomplished. Thanks again!

rswyan · Nov 23, 2014

If it is no longer making noise, what you accomplished was getting rid of the noise ...

I have to take off my MMM tomorrow and I'll have a look and see if I can provide any further useful info.

The way I found out about this was a bit of an fluke/accident ...

I was attempting to take that cover off or move it or something, for some reason or another (nothing related to the noise) and after I did it the noise stopped.

I've rotated it several times since then (our B2910 has 1625 hours on it) to get rid of the noise and it has worked every time.

Haven't really paid much attention to a "proper orientation" ... I just rotate it whichever way I can to stop the noise.

Based on my experience, I suspect this will be an ongoing problem ... dunno if it's really solvable on a permanent basis.

mhart · Nov 26, 2014

Anybody get a chance to take a look?

Baby Grand · Nov 27, 2014

I think rswyan is on the right track. Something's rattling when the vibrations reach a certain frequency. For about half a year I would periodically get a sound like nickles & dimes being shook in a tin can. Really loud & scary. Thought I was losing a bearing. Come to find out the battery hold down was loose. Tightened it up and never heard that sound again.

Threepoint · Nov 27, 2014

This thread is almost as good as one of the old Click and Clack segments on Car Talk.

rswyan · Dec 3, 2014

mhart said:
Anybody get a chance to take a look?

Sorry ... I got the MMM taken off when I said I would ... but it was entirely too cold and wet to go crawling around underneath.

The B2910 is now in the shop and I'm doing the 1600 hour service ... I'll try to get some pics.

To DanW ... the shaft/cover in question is the rear one (closest to the transmission) ... the clamp in question is just to the rear of the two drain plugs for the engine crankcase. It is around a sort of bell-shaped portion of the plastic cover.