Hi All,
I am restoring an old Hoover vacuum cleaner. One end of the motor shaft rides in a K-65 caged needle bearing. I have replaced this bearing with an identical new one (link below) but would like to know what would be the best LIFETIME grease for this bearing and application--I don't want to have to take this thing apart again.
When I re-assembled the motor with the new bearing for the first time, I used some unknown dark grey grease with the consistency of Miracle Whip. This grease sample was given to me by a machinist--he pumps it out of a grease tube gun into the grease points of lathes and mills etc--but I don't know how well it will last in this potentially higher speed and higher temperature application. Is it likely that the volatile compounds will vaporize out of the grease, leaving behind a gummy residue and a loud bearing?
https://www.amazon.com/Koyo-J-65-Bearing...ds=j-65+bearing
Thanks.
High Speed Electric Motor Grease
- Thread starter TurboDieselPoint
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Look at Chevron SRI grease
http://www.chevronlubricants.com/en_US/products/products/chevron-sri-grease-ngli-2.html#.Wj58bCuIbv4
Thanks for the advice, all.
When I looked up the products you all recommended, I stumbled upon this stuff called Mobil 1 Polyrex EM, designed specifically for electric motor bearings. This one seemed like a no-brained, but I still wanted to get a second opinion here. Although it is for electric motor bearings, perhaps it is intended for larger, industrial electric motors which could run slower and cooler than the one I am looking at.
What do you think? Polyrex EM or synthetic wheel bearing grease?
https://www.mobil.com/English-US/Grease/pds/GLXXMobil-Polyrex-EM-Series
And, for that matter, do you guys have tips for stuffing as much grease as possible into that little drawn cup, caged needle bearing (J-65)? I want to fill it as full as possible, then just let the extra leak out as the motor runs.
The bearing has no grease hole, so I just scooped grease onto a Q-tip and worked it in between the rollers as best as I could. I suspect I may be able to get even more in there with a better technique. Perhaps a syringe with a hypodermic needle?
Any tips would be appreciated. Thanks.
Tbh I could hit it with some superlube. As to pumping the grease into it, you can try a syringe, just make sure to get a fat needle on there. Pushing out something as viscous as a wheel bearing grease might be a pain
Don’t pack the bearing full. It will heat up and fling the grease out if overfilled. It should be filled 50 to 80%.
That was my goal. Overfill it, then let it it fling out the extra grease it doesn't want. If it makes a mess, that is ok; I can clean it up. I just don't want it to have it underfilled.
Just curious, how does one determine how full a bearing is? What would constitute 50% full, for example?
Thanks!
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The extra grease makes extra heat from churning and will cause more grease to fling out than you intend to remove. It can cause failure.
There is a calculation for grease fill by bearing type and size. It’s a lot less than you think. For that bearing it would be a good coating plus a little bit more.
JHZR2
Staff member
Originally Posted By: tom slick
The extra grease makes extra heat from churning and will cause more grease to fling out than you intend to remove. It can cause failure.
There is a calculation for grease fill by bearing type and size. It’s a lot less than you think. For that bearing it would be a good coating plus a little bit more.
Yep, there's calls and recommended masses.
About half full will do you.
If you've got a syringe, inject grease on the outside of the rollers, then remove it from the inside before installing. If you can't work the grease into it with finger pressure and rotation until it won't take any more, and then wipe the inside mostly dry.
If you can't then pack the inside without trying to get it to the outside, but it will leak more.
Tom Slicks point is a good one...if too full, it can empty itself when hot.
To select the correct grease base oil viscosity and approximate NLGI grade you need the motor speed and operating temp. Motor speed should be in the manual or on the motor tag. Op temp is probably unknown but 120F can be assumed. The Polyrex Em is the probably the closest grease named to the actual requirement. If motor speed is very high than a lower base oil viscosity will be needed.
I am here to report that my Mobil Polyrex EM has arrived and works wonderfully. This was definitely the right choice for the application.
Thanks to everyone who helped me figure this out.
Glad this worked well for you. Where were you able to order this from? Sounds like something I'd like to keep on the bench.
Originally Posted By: TurboDieselPoint
Thanks for the advice, all.
When I looked up the products you all recommended, I stumbled upon this stuff called Mobil 1 Polyrex EM, designed specifically for electric motor bearings. This one seemed like a no-brained, but I still wanted to get a second opinion here. Although it is for electric motor bearings, perhaps it is intended for larger, industrial electric motors which could run slower and cooler than the one I am looking at.
What do you think? Polyrex EM or synthetic wheel bearing grease?
https://www.mobil.com/English-US/Grease/pds/GLXXMobil-Polyrex-EM-Series
Wheel bearing and chassis grease would definitely be wrong for this application.
Originally Posted By: Piston_slap
Glad this worked well for you. Where were you able to order this from? Sounds like something I'd like to keep on the bench.
Originally Posted By: TurboDieselPoint
Thanks for the advice, all.
When I looked up the products you all recommended, I stumbled upon this stuff called Mobil 1 Polyrex EM, designed specifically for electric motor bearings. This one seemed like a no-brained, but I still wanted to get a second opinion here. Although it is for electric motor bearings, perhaps it is intended for larger, industrial electric motors which could run slower and cooler than the one I am looking at.
What do you think? Polyrex EM or synthetic wheel bearing grease?
https://www.mobil.com/English-US/Grease/pds/GLXXMobil-Polyrex-EM-Series
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