LT40 Rumbling noise around the drive wheel

[Tree Dan]

I have a noise around the drive wheel area.
It starts once the auto clutch is engaged.
I took the blade off and the noise stopped.
Changed the blade, and the noise was still there.
I checked for play in the in the drive wheel, and it seems ok.
Guide wheels are turning ok
Any suggestions?
Thanks for any help.

[terrifictimbersllc]

Check to see if there are any lumps of sawdust/sap under the drive wheel belt?

[Chuck White]

What year, and how many hours on the mill?

Could be the main bearing, check the oil level in it!

[Tree Dan]

Check to see if there are any lumps of sawdust/sap under the drive wheel belt?

That was it...2 lumps of sawdust stuck to the wheel
Thanks...running like a charm now
TD

[Chuck White]

Good to hear, Dan!  8)

[Brucer]

Both the drive and idler wheels have small balancing holes drilled in the bottom of the groove. Under certain conditions (and rarely) sawdust can pack into one or more of these holes. Sawdust doesn't normally stick to the bottom of the groove, but when the hole is completely filled with sawdust more sawdust can stick to it. Eventually you get a lump under the belt and that stretches the blade just a little every time the lump rolls around. This makes he entire head shake, and it's hard on blades and bearings. 

It's easy to fix but I advise checking to make sure you've cleaned the balancing hole out completely when you remove the lump.

I've only had this happen twice, on two different LT40's, and in both cases it was when I was sawing logs covered with thick, sticky snow. It was the drive side both times.

Now I make it a habit to inspect the balancing holes every time I change a bandwheel belt.