OzVMX Forum

Clubroom => Tech Talk => Topic started by: Paulos on February 10, 2016, 11:13:07 am

Title: repacking new sealed bearings
Post by: Paulos on February 10, 2016, 11:13:07 am
I've always pried the cover off new sealed bearings and packed with grease as they seem to come with a measly amount of grease when you buy them. 

A mate was told by the guy at the bearing shop not to do this though, as too much grease will cause the bearing to overheat and the small amount of grease in there is all you need.

I'm not too keen on this idea though. Any thoughts?
Title: Re: repacking new sealed bearings
Post by: Rossvickicampbell on February 10, 2016, 11:31:01 am
too much grease overpacked will cause overheating - however define too much grease????
Title: Re: repacking new sealed bearings
Post by: fred99999au on February 10, 2016, 02:33:03 pm
The amount of grease in a bearing that causes overheating?
Title: Re: repacking new sealed bearings
Post by: rocketfrog on February 10, 2016, 03:14:12 pm
If you repack the bearing you can be assured of the the suitability of the grease for your particular application. Ask your bearing supplier if the factory grease is suited for your purpose at least. I suspect that the bearings are initially packed with a preservative type grease and I prefer to use quality wheel bearing grease ( if I am using the bearing for wheels) so I know it will be up to the task.
Title: Re: repacking new sealed bearings
Post by: zorroz on February 10, 2016, 03:42:28 pm
I've always packed one side of a new bearing with good water proof grease and they have lasted 5 years on an enduro bike. But on wheel bearing that were never packed they failed with in a few years. Do it  8)
Title: Re: repacking new sealed bearings
Post by: pecrazy on February 10, 2016, 04:55:14 pm
I always pop on seal and add some grease or a bit of moly lube or other slippery stuff.
Title: Re: repacking new sealed bearings
Post by: EdgyAl on February 10, 2016, 05:07:13 pm
What a crock of poo,
He should sell vacuum's.
Grease those suckers up.
Title: Re: repacking new sealed bearings
Post by: Moto on February 10, 2016, 05:20:44 pm
I was taught when doing this on electric motor bearings to pack them 2/3rds full to stop overheating.On my bike wheel bearings I wash out the original Vaseline they come with and repack with Belray waterproof grease and as said by others they last for years.
Title: Re: repacking new sealed bearings
Post by: yamaico on February 10, 2016, 07:26:12 pm
If you are going to pack them always do it with the palm of your hand:

https://www.youtube.com/watch?v=P_tSJq9zc-M

I know it says wheel bearings but use the same procedure on roller bearings. It's the easiest way to get the grease where it's supposed to be, just a bit messy..
Title: Re: repacking new sealed bearings
Post by: fred99999au on February 10, 2016, 09:46:22 pm
Thats funny. That is how I was taught many moons ago.
Title: Re: repacking new sealed bearings
Post by: matcho mick on February 10, 2016, 10:25:06 pm
yep,std procedure,tapered bearings sharp edges cleaned your palm up pretty good too, ::), :P
Title: Re: repacking new sealed bearings
Post by: FourstrokeForever on February 11, 2016, 08:26:19 am
Yep, wash the vasoline out and repack with good quality wheel bearing grease. They will last for years, even longer if you do it every year or so.
Title: Re: repacking new sealed bearings
Post by: dont on February 11, 2016, 10:26:22 am
I have one grease gun dedicated to do bearings, it has a large bore hypodermic needle as the outlet and I fill the centres between the balls, rods, and the opened side. With wheels I put the side I've opened inward incase the seal was damaged.
Title: Re: repacking new sealed bearings
Post by: Tony.Brown on February 12, 2016, 11:39:52 am
Now call me a cynic, but why would a person who sells bearings for a living tell you not to re-grease your bearings? I wonder?
Title: Re: repacking new sealed bearings
Post by: Tim754 on February 12, 2016, 12:27:28 pm
I’m still having a shit load of trouble making ceramic ones on me pottery wheel...........
Title: Re: repacking new sealed bearings
Post by: EdgyAl on February 12, 2016, 05:13:25 pm
I’m still having a shit load of trouble making ceramic ones on me pottery wheel...........
Tell Patrick Swayze to go home and you might be more productive.
Title: Re: repacking new sealed bearings
Post by: Lozza on February 12, 2016, 09:21:05 pm
I’m still having a shit load of trouble making ceramic ones on me pottery wheel...........

Time for some automation then Tim  :)
https://www.youtube.com/watch?v=41Z5v4NybWA
Title: Re: repacking new sealed bearings
Post by: shelpi on February 14, 2016, 02:21:11 pm
I’m still having a shit load of trouble making ceramic ones on me pottery wheel...........
LOL good one
Title: Re: repacking new sealed bearings
Post by: chrisdespo on February 22, 2016, 10:50:48 am
back in the seventies when i was racing 125s and 250s both mx and road i would just change the bearings regularly before they got a bit rough never bothered repacking them as the more grease you put in the more drag that they have but used to give them a squirt of oil. when i got back from a meeting after the bikes were washed they would be pulled completely down and cleaned from stem to stern generally on the monday morning before the workshop got too busy and check every thing like all bearings and bushes not a huge job then get the first year to give it all a good wash and re assemble generally monday night frame wise that is and the engines would get checked later in the week and rings or pistons replaced as needed. in the scope of things wheel-bearings are very inexpensive items.
i would say check and oil weekly only need a little of some good oiled if the seals aren't damaged you won't have any problems. Oh and by the way std sealed ball races will function on a conveyor belt with just a tiny amount of grease added like a pump every couple of days for ages.
Title: Re: repacking new sealed bearings
Post by: Rossvickicampbell on February 22, 2016, 10:54:13 am
conveyor belt bearings run a lot slower though don't they Chris?
Title: Re: repacking new sealed bearings
Post by: shelpi on February 22, 2016, 11:25:25 am
just been doing maintenance on fans for Adelaide Brighten Cement average shaft size 75mm  SKF bearings
one particular bearing stood out it was overly packed with grease mobilith sch 220 synthetic to be exact and that bearing got very hot indeed outer race was straw in colour and baked on grease
so more is definatly not better
and after we repack bearings the drag increase is very noticable