R51/3 - Wheel Bearings: To seal, or not to seal
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Stacey Zabolotney
R51/3 - Wheel Bearings: To seal, or not to seal
I'm just replacing my wheel bearings on my 1954 R51/3 (Full hub) The bearings are 6204. Anyway, when one gets them new, they are a sealed unit. I was going to pop off the rubber side seals, but then thought it may be better to keep them on, they'd stay nice and clean, and they aren't servicable from the outside once installed, as you pretty much have to pound the bearing out in order to clean and regrease them anyway. Would there be any reason to make the pop off the rubber side seals, to make them like they were originally?
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Allan Atherton
Re: R51/3 - Wheel Bearings: To seal, or not to seal
I think I have heard it recommended that the seal be removed from the bearing, because in this application, dirt and sand can get between the seal and the axle and wear a groove after many thousands of miles. Then new bearings and seals will not be able to seal unless the axle is also replaced.
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Allan Atherton
Re: R51/3 - Wheel Bearings: To seal, or not to seal
On second thought, what I heard concerned bearing seals, not sealed bearings. Some people say the original felt seals are better than the modern rubber seals, because the felt does not press dirt and sand against the axle.
On the question about sealed bearings, many bearings come this way, and I have seen people take the sealed bearings and remove the seals before using them, but I can't remember if the bearings were going to be used in the motor or in the the wheels. Maybe it is OK to use sealed bearings in wheels, but I would feel better if the seals were removed so the bearings could be greased the usual way.
On the question about sealed bearings, many bearings come this way, and I have seen people take the sealed bearings and remove the seals before using them, but I can't remember if the bearings were going to be used in the motor or in the the wheels. Maybe it is OK to use sealed bearings in wheels, but I would feel better if the seals were removed so the bearings could be greased the usual way.
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rolf
Re: R51/3 - Wheel Bearings: To seal, or not to seal
Hallo,
the rubber seals are not for protecting the bearings from dirt(inspite of many people think so), they are only for keeping the grease inside the bearings, so why pop off? no reason to do it.Do you really want to regrease the bearings after a while(5000km, I do not know or 20.000km)? The "Filz" washers are in place too, I think?
You can pop off the rubber, but it makes no sense.
rolf
the rubber seals are not for protecting the bearings from dirt(inspite of many people think so), they are only for keeping the grease inside the bearings, so why pop off? no reason to do it.Do you really want to regrease the bearings after a while(5000km, I do not know or 20.000km)? The "Filz" washers are in place too, I think?
You can pop off the rubber, but it makes no sense.
rolf
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Allan Atherton
Re: R51/3 - Wheel Bearings: To seal, or not to seal
I wonder if the sealed bearings work properly in BMW wheels. The seals keep the manufacturer's grease in, but they keep your grease out.
When greasing the bearings, you pack grease into the bearing, you cover the bearing stack with grease, and you push grease into the hub around the bearing before installing the wheel seals. The open bearing assembly thus gets a lot of grease in and around it.
A sealed bearing does not have much grease in it. I am not sure that a sealed bearing was intended by BMW for use as wheel bearings. I would prefer to pop off the seals and grease the bearing assembly myself.
When greasing the bearings, you pack grease into the bearing, you cover the bearing stack with grease, and you push grease into the hub around the bearing before installing the wheel seals. The open bearing assembly thus gets a lot of grease in and around it.
A sealed bearing does not have much grease in it. I am not sure that a sealed bearing was intended by BMW for use as wheel bearings. I would prefer to pop off the seals and grease the bearing assembly myself.
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Stacey Zabolotney
Re: R51/3 - Wheel Bearings: To seal, or not to seal
I may just leave the sealed bearing intact. As I am able to pop the seals off the sealed bearing very easily, and they also pop back on just as easy. This way I will be still be able to service them, but they should stay cleaner longer. I know that the engine bearings shouldn't use the sealed bearing, as oil needs to flow through everything.
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Allan Atherton
Re: R51/3 - Wheel Bearings: To seal, or not to seal
I would be concerned that sealed bearings might not provide as much grease in the bearings as BMW intended.
I don't think bearings are sealed to stay clean - the wheel bearing seals on the axle do that.
I think bearings are sealed to keep their grease in, which also keeps other grease out.
And I think sealed bearings have less grease in them than you would put in an unsealed bearing, and no possiblity of receiving grease from the rest of the bearing stack or assembly.
But it would take many thousands of miles, and perhaps years, before any problem appeared, if there indeed was any problem. So the pros and cons of sealed bearings are rather theoretical.
I don't think bearings are sealed to stay clean - the wheel bearing seals on the axle do that.
I think bearings are sealed to keep their grease in, which also keeps other grease out.
And I think sealed bearings have less grease in them than you would put in an unsealed bearing, and no possiblity of receiving grease from the rest of the bearing stack or assembly.
But it would take many thousands of miles, and perhaps years, before any problem appeared, if there indeed was any problem. So the pros and cons of sealed bearings are rather theoretical.
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rolf
Re: R51/3 - Wheel Bearings: To seal, or not to seal
Hallo Allan,
you are right with greasing all the surroundings of the bearings, but you can do this also with sealed bearings. If you grease a bearing: do not take too much grease, for a bearing of this size a piece grease of the dimension of a pea was more than enough, more would not help( worse, it would not be good). In the moment , I do not know if the BMW-manual says it or the"manual" of SKF(or INA etc).If I remember well, too much grease could destroy the bearings because they could get too hot.
Greetings
rolf
you are right with greasing all the surroundings of the bearings, but you can do this also with sealed bearings. If you grease a bearing: do not take too much grease, for a bearing of this size a piece grease of the dimension of a pea was more than enough, more would not help( worse, it would not be good). In the moment , I do not know if the BMW-manual says it or the"manual" of SKF(or INA etc).If I remember well, too much grease could destroy the bearings because they could get too hot.
Greetings
rolf