Sorry in advance for the necro post but i’ve also had issues with bearing failure and i discovered the problem. Almost all of these “cheap” consumer grade shop vacs (shop-vac, ridgid, stanley, etc etc) are largely made by the same company named Emerson. As a cost cutting measure for a world that has become stuck on cheaply made, disposable products… Emerson has designed a motor with only one sealed ball bearing, and on the other end of the motor shaft is a bronze “Oilite” ( https://oilite.com/ ) type bushing surrounded by felt that holds the lubricating oil. While i have nothing against such a bearing in general (they work just fine in my 100 year old GE table fan), the use of them in this motor design where they are not serviceable is clearly a way to make these vacuums have built in obsolescence. Or to put it bluntly, they self destruct once the oil is used up, overheating the bearing and motor causing a thermal fuse to break, disabling the vacuum. Typically such oil bearings are accessible in properly designed devices and can last many decades with very little maintenance but not in this case.
A while back I did take apart my 14 gallon Rigid shop vac when I heard a change in the sound of the motor and i’m kicking myself for not taking photos, but as I thought, the felt that once held a supply of il was dry. I gave it a good dose of 3-in-1 Oil for electric motors (comes in a blue can), put everything back together, and it ran like new again. Keep in mind, i did this well in advance of a bearing failure and was able to prevent the issue. The longer you run the motor, where it begins to squeel loudly, a re-oiling may not be enough because the friction smears the surface of the oilite bearing causing oil to no longer flow through its highly porous structure.
After a bit of searching, it seems a guy on youtube who was also having the same problem came up with a MUCH better solution than re-oiling, and that is to replace the bushing with a 608-2RS ball bearing which just happens to fit perfectly into the housing.
Check it out! https://youtu.be/KdTgQGFfy9o
I will be doing this to my Ridgid 1450 vac in the very near future.