How Much Grease To Use?
 

The video is a presentation I made at the 2024 NLGI Annual Conference. It asks more questions than provides answers namely "how much grease to put in a bearing?" Well, I don't know? This video explains the positions of a few awesome companies. Have a look and please let me know what you think.

https://www.youtube.com/watch?v=VS3uVXvml2U

Hmmm..

Cool, I'll watch the video. I've always heard, "squish it in until it comes out the other side".

Yes, it's definitely a case of Grease is the Word. I also force the stuff in until it comes out the other side.

I just pack them as much as I can... The bearing will eject what's not needed on its own.

I haven't watched the video but will when I have time.

My current mantra is that grease is cheap compared to a failed bearing. I may update that after watching the video...

BTW I've been using Slick 50 grease for almost everything for more than 25 years (from bicycles to wheel bearings).

No problems so far.

Ditto.

^ Yup...Bearing companies hate that!

Just for info: I "regrease" noisy serpentine belt pulleys and it's easy.

Gently remove one of the seals. Clean out what's left of the old grease.
Jam some new stuff in but don't fully pack it and then reinstall the seal (the seals don't have to be in perfect condition).

I first did this as a stop gap because there was a delay getting a new pulley from my parts supplier.
- I ended up running the "regreased" pulley with no issues for well over 60,000kms.

I pack 'em full of grease and forget 'em. They growl when they want attention. I've seen fewer old age bearing failures than failures caused by 'fixing' them when they ain't broke.

Okay...I'll modify that. For a non-sealed bearing that has been in situ ungreased for years, I'd consider cleaning and regreasing. But this is just not something I do every 2-3 years like some folks. And....never had much trouble. Had more trouble with sealed bearings.

Same with CV joints. Pack 'em FULL. When the boot tears, replace the entire axle.

I attended a seminar on mechanical things and we used a ultrasonic meter to listen to the bearings and added grease until the pitch of the noise got very quiet. That is when the instructors said that was the correct amount of grease.

They also had a contest where you pumped grease onto a piece of paper until you thought you pumped one ounce of grease. I got lucky and did 20 pumps on the grease gun and hit one ounce.

Dave

I watched the video. It seemed that several of the formulas were based on the outer dimensions of the bearing. As you addressed, obviously, that's silly since the bearing isn't a hollow void, its only going to hold a little bit of grease compared to the volume that the outer dimensions make up.

My take from the video was "force it in until it starts coming out and then you're good."

If I'm doing brake work on a car and have to pull a hub with bearings, I'll clean and relube the bearings if I'm not replacing them, but if I'm pulling and replacing anything, I generally replace the old bearings too so the new bearings must be lubed.

I think the real question is, can you ever put too much grease in a bearing?
I'd think most are 'self regulating' in a sense as they'll expel what they don't 'need'.
I could be wrong on this too.
I do remember Dad always had us boys repack the trailer bearings before each and every vacation. We got good at it since it was a tandem axle trailer. We never had a bearing failure, like Dad did when he went on a family trip to Alaska back in 1948 and they had a bearing go out in the middle of nowhere on the Alcan highway.
I think that's where his discipline of repacking before each trip came from.