Cascadia eaton 10-speed, odd noise?

Sounds like an overdrive 10 speed. 9th being direct would put power straight through with no load on the countershafts.

Makes me wonder if there's a countershaft bearing starting to go?

 

You have to pull the tranny and bell housing to get to the front ones.

 

Don't know. But a five gallon bucket of 50wt is cheap. Takes about three gallons to fill it. I recommend buying a bucket pump. They're about forty bucks.

 

Have you checked the gear oil level? Usually when they sound that way they are low or out. Does it make the noise at idle? Does the noise quit if you mash the clutch down for a minute?

 

A model is mighty close , pop the filler plug and see where the oil level is , should be up to bottom of plug , if it's way low ,may be too late , upper bearings may need replacing. Get a magnet on a flexible handle and move it around in the bottom of the tranny , will be small wear particles ( normal ) ,bigger pieces may be bearing flakes or bearing cage. Flaking or cage gone will enable it to growl.