Install new sealed bearings instead, then you dont have to grease. If theres a VFD, then you want to buy bearings with a grounding ring and they will last as long as the motor will (with proper belt maintenance).

No heat gun would be sufficient. Its to make the inner ring expand larger so it slides over the motor shaft smoothly.

The kind of grease depends on the bearing manufacturer. They almost all recomend a poylurea grease (blue). SKF recommends their own LGHP2 I believe, while everybody else (WEG, Baldor, US Motors) recommend Mobil polyrex. The first factors to look at in early bearing failures is alignment, load, balance/vibration of the load. This accounts for 16% of bearing failures. You need to read and make sure the motor is rated for the use (belt driven equipment, direct coupling, or overhung) The second factor is lubrication: intervals, amounts, contamination, overheating, seals popped off, etc account for 36% of bearing failures according to SKF. Make sure you do it right. A third factor to look into is if you have a VFD running the motor. It’s not too much of a concern on Danfoss and ABB drives, but cheaper drives are known to kill bearings. The motor needs a shaft grounding brush (Aegis is a good no maintenance option that motor manufacturers put into their higher end motors). The wires have to be run in such a way that they don’t induce a current through the ground wire, and you need to make sure you don’t have common mode currents going through. You can clamp around all three phases at once, if this doesn’t read 0 amps then you have current going somewhere, likely arcing through the bearings and killing them. You would need a common mode choke to get rid of this. VFDs can also cause premature failure if you are using them to overspeed the motor (above 60Hz is overspeed). Although all good motors nowadays are rated for 90Hz to account for this.

The thing I don't like about the grounding brush is if maintenance over greases, they're insulating the brush and it becomes useless. I always install the external shaft grounding kit. Also, no grease is better than too much grease.

@@BelleTheBoston8weeks yet another reason to buy sealed bearings

Yup

To be honest im not sure what temp it gets them to. I set the heater to 350F then wait about 10 minutes and its good. Not enough to cause grease to smoke

Ya I've learned that one the hard way. I recommend it to all customers but many choose not to sadly. Another factor on this one was the belts were overtightened for to long causing axial stress.

back EMF

My dude, your grammar is trash and makes it hard to read what you were trying to type here. Plz proof read before posting.