Greasing Bearings - DIY

I knew a guy who did this with snowmobile suspension wheel bearings. I bought a sled from him (old Indy 500) that had 21,000 miles on it. It had the original bearings in the suspension. He used a needle injector on his grease gun. The sled also had the original top end in it. I sold it 6-7 years ago and as of last year it was still running.

SeaHorse, Aussies are renowned for the tall poppy syndrome for which I do not want to expose here, I admire your work, although can I suggest from industry experience that you replace kerosene and contact cleaner for WD40 or similar. Also bearing manufacturers' have proven the required amount of lubrication (as little as it seems). The excessive amount of grease simply forces itself out, even through the seal. Replacing the original grease with water resistant grease is a winner though. Cheers.

I have the same industry experience, in fact in my line of work if I pack a bearing that full I end up with a high speed siezure due to overheating.
Bearings are packed 50% or less in my book. Great write up though!

quote="Kreza, post: 234099, member: 6594"]SeaHorse, Aussies are renowned for the tall poppy syndrome for which I do not want to expose here, I admire your work, although can I suggest from industry experience that you replace kerosene and contact cleaner for WD40 or similar. Also bearing manufacturers' have proven the required amount of lubrication (as little as it seems). The excessive amount of grease simply forces itself out, even through the seal. Replacing the original grease with water resistant grease is a winner though. Cheers.[/quote]

So, I just repacked my rear wheel bearings full to the max, and I go 60-65 mph on my bike. Are my rear wheel bearings going to heat seize?

McKay, could you comment on the amount of grease in the OP, it looks like 50% or less in that 3rd pic.

I have been packing as much grease in my bearings as I can for years and never had a problem. Dualsport bikes that go 100+ MPH and cruise at 60-80MPH for hours included. After I put the bearing in the hub, I fill the space between the bearing and seal with grease too. With all that grease there is little room for mud, which I think is the main enemy of bearings in dirt bikes.

I recently bought a used bike and I'm in the process of checking it out and made an interesting observation. A previous owner had packed all the wheel bearings and outer hub areas with grease, but apparantly forgot one front bearing. You guessed it, only that one front bearing with the original grease needed to be replaced because of dirt and rust.

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Yes, this is an interesting subject,
I always thought that if it was full of grease mud has nowhere to go into the bearing, seems to have worked for enduro applications over the last 35 years for me, but if you talk to a bearing company there is more to learn as most new bearing I need come with only about a 20% 'fill'

20 to 50% works very well in high speed bearings. Do I think everyones bearing are going to explode that pack them fuller? No, of course not. The purpose of grease is not to keep mud and debris out, it is to keep the races and bearing cool. Quality of grease is important as well, I know that All Balls and other re-branded Chinese produced bearings have grease quality issues as well as machining issues. Buy the best you can and use a good quality grease.

FWIW Kerosene and contact cleaner are a pretty good choice for cleanups before repack, I would not use a penetrating oil for this kind of work.
Every way works to some degree or another, I just stick with what I know and practice everyday.

Crap, I went out yesterday and took some grease OUT! Now, I guess I'll go out there and put it back in! Still waiting for my linkage bearings, goin' a little stir-crazy...

I found this from 2009. Great pictorial on front wheel bearing maintenance.

http://www.cafehusky.com/threads/diy-front-wheel-overhaul-parts-1-2-3.5416/

Obviously a topic which some are very passonate about and have their own strong opinions on.

Like most items, you get what you pay for - I really wouldn't trust items manufactured in China, as someone earlier mantioned re All Balls - they are knock offs! They are generally produced to a cost not a standard. The other item of importance is the oil seal, this is the first line of defence of keeping water out so quality counts again..
The things that kill bearings are heat and water(dirty water). One of the worst things to do to a bike after a ride is to go mad with the high pressure water blaster and blast water into those bearing areas past the seals.
As to the amount of grease and type, again quality - a good water proof grease in the bearings at least 50% full, the purpose of grease as it heats in a bearing is to become slightly liquid to lubricate the balls and race. The solid state of grease means it dosen't all run out like oil - eventually the race will become dry with use if they are not repacked regularly. Probably the best thing to do after installoing the bearing in the wheel hub is to pack the outer hub with grease and then install the outer oil seal (not the bearings seal) this will keep water out of the hub and protect the bearing.
Bearings like chains and sprokets etc. are disposable maintenance items - they will last longer if you maintain them but they will eventually need to be replaced.

If the bearing is being used in a low speed application example: dirt bike wheel at about 120 kph = about 1000 rpm.. Personally I have and
always will fill the bearing to about 90-95% full.. I also fill all gaps between the bearings and the seals.. On the other hand in a high speed
application example: electric motor at 20,000 rpm you do not want to overfill.. Cheers..

The below information was from the Koyo website..

Our main rotors tun at 390 rpm, cant pack those full. May have more to do with loading than rpm.

Just repacked my linkage and wheel bearings when changing tires. All look beautiful and they are the all original. I repack the linkage 1 time year, and the swing arms about every 18 months (should probably do it every year). I just repacked my wheel bearings for the first time and was surprised they looked so well. This is my 4th season with my 09TE450. Its real comforting to open them up on a schedule like that and almost feel like you are wasting your time because they look so good: if you have ever dealt with rusty crusty bearings. The first initial greasing session after purchase/set up is the most important.

Another suggestion is that you can use a needle greaser on your grease gun. I buy high end synthetic grease for the guns and then use them to deliver what I need where I need it. Makes it easy to grease sealed bearings.

http://www.grainger.com/Grainger/WESTWARD-Injector-Needle-1ZTC7?Pid=search

Well done. Not many people realise that you can pop the seals out and grease or re-grease the bearings, an almost forgotten trick from the past. One thing to note that that you can change the grease type based on the expected rpm of the bearing. Belray is excellent for slower bearings such as wheel and steering head. I tend to use amsoil on bearings that will rotate faster as it is a thinner grease. A side note is that Belray grease is calcium based and not compatible with other greases like lithium. You must clean the old grease away. I did a test using my I/O boat and prop and painted different waterproof greases on each prop blade, then went to the lake. The Belray grease was the only one left at the end of the day. That is good stuff. Cam.

Great idea and a worthy test!