I've used 20W Non-detergent oil on blower motors (up to 2HP) and regular house fans with very good success...I tried using regular 30W (w/all the additives, including the detergent) and ended up "gumming up" the house fans...they failed, generally within 2-3 days of treatment.
I don't remember where I saw/heard the suggestion to use the 20W ND stuff, but since I did, that's the only oil I'll put on blower/fan motor bearings.
You can, usually, get the stuff at an ACE or Hardware Hank stores...the stuff I'm using comes in a pint-sized squeeze bottle that has an ant-eater tube stuffed down its cone-shaped applicator tip (to enable you to reach into those hard-to-reach areas on some fan motors...).
To give you an idea how good this stuff has been, I have a tentant in my building that brought over a 12-year-old transmitter that he had since it was new. It had been on the air for all that time at its old location and he moved everything over to our building due to rental/utility costs being MUCH LOWER than where he was at... Anyways, about 6 months after he moved in and had the transmitter running, I came in one day to the delightful sound of a squealing bearing...sure enough, the "new box" - and there was a "red dust" that had developed on the one end of the blower motor (This blower IS VERY IMPORTANT TO KEEPING THE TRANSMITTER ON THE AIR...IT KEEPS THE TUBE COOL...) (Now, catch the conversation I have with the owner, over the phone...)
ME: "Hey, John...the blower is squealing really bad...when was the last time you oiled this thing?"
JOHN: "Never. I didn't know I had to do that."
ME: "In the maintenance manual, it says to oil the blower motor at least twice a year."
JOHN: "Oh. Well, I have a few of these things around the country, maybe I better have a look at them. Would you mind taking care of that one for me?"
ME: (Rolling my eyes towards the heavens) "Sure John. No problem." (Murphy is warming up the toe of his boot...
) "I'll squirt in a few drops and that should take care of it."
About 35 drops, per bearing, later...the motor has quieted down, even more so than when it first arrived. Thankfully, the caps to the bearings were on the top-side of each bearing race...the rear was easy to get to, the front area was designed and placed inside the cabinet by Murphy himself. Guess which bearing was making the most noise? Yep, Murphy's bearing.
This occurred back in '92...guess which part has never been changed on this transmitter, regardless the abuse it suffered before it came over to my building? Yep, that blower with its "Murphy bearing" in the front...my least favorite thing to oil in spring and fall...but, they both get a drink regardless the fun it takes to give it to them...and now, it only takes about 5 drops and they're happy...
Important thing to remember...if the manual says to do it, doing it sooner is way more important and smart than doing it later, if not at all. And, if someone suggests that you do it and manual doesn't say anything about it...check it out and do it anyway. You never know who approved the manual...either the techs did, or Management/Sales did.
I'll trust the techs LONG BEFORE I'll trust Management...I should know, I are one! (Guess which?
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