ADDING GREASE TO SEALED BEARINGS

[grsr3]

SOME FOOD FOR THOUGHT

THIS NOTE IS MAINLY FOR OWNERS THAT HAVE CONCERNS ABOUT SEALED THROW OUT BEARINGS THAT APPEAR TO BE "GREASABLE".

My bearing supply guy says that sealed bearings come from the factory with about 50% grease inside. Adding more to this can actually create heat build up and do more harm than good. Of course if there very little grease left in there I suppose it would be good to add some---but how would you know???

GEORGE

 

[Skyco]

You also have to know WHAT grease is in there...some are not compatible.

 

[KYErik]

I have heard that some guys use a small needle and syringe to inject extra grease through the rubber seal of a sealed bearing, but I have never tried it. I would think it might just leak back out the needle hole in the rubber.

It might be worth a try if you have a dry and noisy bearing and are just 20 minutes from finishing a hay baling job while rain clouds are gathering...

 

[diyDave]

How do you tell if a sealed bearing needs attention? The way I tell is by using a non-contact IR thermometer and pointing it at the bearing in question. Then point it at another bearing of similar size on the same machine, and compare. I did this on my Hesston round baler, and was able to see about 30 degrees difference between the two, so I put on my thinking cap, got out the can of Kroil, sprayed the hot bearing, and it cooled off. So now, before I bail, I oil that bearing. 3 years and counting, without having to change out that sealed bearing!

 

[RichNJKubota]

I used to have a large syringe (medical type - had a large hole in the needle) that I used to put grease into noisy "sealed" bearings.
Now I just use an oil can. By the time the bearing gets old the seal is shot too. Oil seeps right in. If it's a bearing I want and need to last I use synthetic oil. Synthetic oil will make a noisy bearing more quiet than regular oil.
For new sealed bearings I would not do anything to them.

 

[D7E]

You can buy a needle that fits onto a regular grease gun from most automotive stores ,Pierces the rubber seal and and makes such a small clean hole that no dirt enters . Very common with 20 year old machinery where packed grease has dried up . I have an 8 row JD corn planter that has sat outside for 20 years and every spring just give em a shot with the needle and i don't recall ever changing a bearing .

 

[grsr3]

GREAT STUFF GUYS---THANKS FOR ALL THE GREAT IDEAS. TOOO BAD I DIDN'T KNOW ABOUT THIS STUFF BEFORE THE FACT.
GEO.

 

[skipmarcy]

I'm sure there are many sealed bearings that don't have removeable seals but alot of them do - you can gently pry the seal out, wash, inspect and grease the bearing and reinstall the seal. Most are thin steel or aluminum with the rubber coating. If you bend it you can usually straighten it out pretty well.

 

[J_J]

SOME FOOD FOR THOUGHT

THIS NOTE IS MAINLY FOR OWNERS THAT HAVE CONCERNS ABOUT SEALED THROW OUT BEARINGS THAT APPEAR TO BE "GREASABLE".

My bearing supply guy says that sealed bearings come from the factory with about 50% grease inside. Adding more to this can actually create heat build up and do more harm than good. Of course if there very little grease left in there I suppose it would be good to add some---but how would you know???

GEORGE

Sealed bearings are not designed to be to be regreasable. Can you do it, sure can, but you lose the sealing properties of the bearing. If it is out of grease, there is a good reason. Maybe you are working it to hard, maybe it's the wrong bearing. Someone mentioned oiling a bearing. Oil is not the same as grease, it will usually sling off. Grease is designed to release the remount of lubricant.

Bad bearings are usually found by by an increase of the noise level. Some are found by smell, such as metal burning. Someone mentioned an in fared thermometer gun, they can be very useful.

Some bearings are greased as regular maintenance. Especially those that have no seal. Some bearings have a seal on on one side. these are designed to mounted a certain way. Usually the seal side is to the outside. These bearings can be lubed by a grease fitting which is located on the unsealed side, such as a spindle bearing on a lawn mower. Some bearings are double sealed to protect it from the elements, such as water, dirt, etc.

I have even seen situations where there were two sealed bearings, on a spindle, with a grease fitting in the middle of the spindle. The people would try and grease the bearings, and when they see grease ooze out, they thought they had done a great job. The grease will come out from where there is the least resistance. Should you, will you, could you grease all bearings, only those that are trying to economize should attempt this. It might give a little more life. That is my story, and I am sticking to it.

 

[Charolais]

SOME FOOD FOR THOUGHT

THIS NOTE IS MAINLY FOR OWNERS THAT HAVE CONCERNS ABOUT SEALED THROW OUT BEARINGS THAT APPEAR TO BE "GREASABLE".

My bearing supply guy says that sealed bearings come from the factory with about 50% grease inside. Adding more to this can actually create heat build up and do more harm than good. Of course if there very little grease left in there I suppose it would be good to add some---but how would you know???

GEORGE

I've used a grease needle on sealed bearings. Metal and rubber seals both. On the metal seals you can drill a very small hole in the seal, push the needle in the hole and apply the grease. Once you have the grease in, you can get that bearing turning and any excess will come out of the hole. Then stop whatever is turning the bearing, clean all the grease off and apply any type of silicon gasket maker sealant. Then let it set for 24 hours and no more grease will come out and no dust/dirt will get in. I've been doing that for over 20 years. An old machinest showed me how. I have bearings on a round baler that I add a couple of shots every 3 years. Had a 1217 JD hay conditioner for 16 years and greased every sealed bearing on it with a needle. I use the sealant on the rubber seals too.(a little dab'll do you) I also grease through the rubber covers on CV joints and seal the holes on those too. Just make sure you give the sealant/gasket maker 24 hours to fully cure.

Oh when and if you driil through a metal seal make sure you have full control of the bit so you don't touch a ball or roller in the bearing. It's not hard to do but you must take care in what you're doing. And don't forget to purge the bearing before sealing.