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> New 914 rear wheel bearing, No to very little grease from manufacture
davep
post Apr 12 2019, 10:25 AM
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There is a good possibility that there is a bearing shop near you that sells that brand of bearing. Have them look at it and express an opinion. Then we will have some more information.
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bbrock
post Apr 12 2019, 11:21 AM
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QUOTE(Luke M @ Apr 11 2019, 05:30 PM) *

I got around to repacking the bearings today.
I opened up the second bearing and found that it had a little more grease in it.
The grease looked better in this bearing also not as chunky but still didn't seam or feel right. I cleaned it all up and installed new grease. I feel better now knowing there's grease in the bearings. I would hate to do this all over if a bearing failed.

Check the pics and you decide if that's enough grease in there.
I can tell you this, one bearing was 90% dry on one side.


This is my totally NON-EXPERT opinion so take it for what it is worth, but that bearing looks pretty good to me. Even though part of it is dry, it looks like there is enough grease in the right places that it would be dragged around and coat everything in the first few revolutions of the assembled bearing. But what the heck do I know? It's way more grease than I found in my worst bearing anyway. (IMG:style_emoticons/default/confused24.gif)
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Morph914
post Apr 12 2019, 01:15 PM
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Out of curiosity I took apart my old one that appears to be original ( SKF) and then a new Beck Arnley bearing to compare. I found both to have, what I feel, is plenty of grease. Attached Image

John

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Superhawk996
post Apr 12 2019, 01:16 PM
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Superhawk996
post Apr 12 2019, 01:24 PM
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Any of you guys checking the bearing grease on your daily driver vehicles?
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bbrock
post Apr 12 2019, 01:38 PM
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QUOTE(Superhawk996 @ Apr 12 2019, 01:24 PM) *

Any of you guys checking the bearing grease on your daily driver vehicles?


Funny you should mention that. Our DD is a Honda that has an appetite for rear wheel bearings. It is our newest vehicle and is now on its third set. I had the first set replace by the pros which cost me dearly. In contrast, we have two Nissans purchased new in the early 90s with over 250,000 miles on them still running their original bearings. Last time I replaced bearing on our DD, I didn't know about checking the grease, but you can bet that if I have to replace them again, I'll be checking and possibly repacking. They were all chewed up inside like the one in the vid you posted but I didn't pay attention to the amount of grease.

BTW, the bearings that @Morph914 showed have the amount of grease I would expect to find when opening a new bearing. Neither of the ones I popped open had that much.
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Superhawk996
post Apr 12 2019, 02:34 PM
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The other thing that drastically affects durability is pre load on the bearing. 914s rear is a double row ball bearing with a split inner race. The torque you put on the hub to CV stub is what creates Pre Load.

Over torqueing that joint will lead to too much bearing preload. Let’s be honest how many of us have put a little “extra” torque on that torque wrench just for good measure - cause we all know tighter is better. I’ve done it in my younger years.


Likewise I trust that it is common knowledge that rolling a 914 without that CV stub installed will lead to bearing failure in very low miles.

Lots of other uncontrolled variables in all these intrawebz / YouTube discussions could be leading to perceived grease failures.

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Superhawk996
post Apr 12 2019, 02:41 PM
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Out of curiosity what type of Honda? Im curious what type of bearing it is using.

Many of the new bearings are called GenIII bearings and have an orbitally formed hub that establishes Pre load. Mechanic really can’t screw those up like GENI (914 type) or GenII bearings.
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bbrock
post Apr 12 2019, 02:52 PM
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QUOTE(Superhawk996 @ Apr 12 2019, 02:41 PM) *

Out of curiosity what type of Honda? Im curious what type of bearing it is using.

Many of the new bearings are called GenIII bearings and have an orbitally formed hub that establishes Pre load. Mechanic really can’t screw those up like GENI (914 type) or GenII bearings.


It's an '06 CRV. Not sure what kind of bearing. When I had the first ones replaced at the dealer, the mechanic made some comment about them being a common replacement item. I think I replaced them with Nationals. The only thing special I could find on the install was getting the ABS dealie on the correct side. To be fair, the car has a lot of miles on it, but I've never had to replace rear bearings as much as with this car. Otherwise, the car has been bombproof.
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Superhawk996
post Apr 12 2019, 03:32 PM
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Can’t tell for sure but it appears from YouTube (here we go again !) that 06’ CRV rear bearing as GEN1 double row ball bearing. In was 07’ it looks like they went Gen3 wheel and hub. I can’t tell for sure what they are doing on 2wD versions but I assume you are AWD given your location.

So again, like 914; torque on the rear hub is what establishes Pre load.

The other thing up for discussion is seal life. A contaminated bearing won’t live long.

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bbrock
post Apr 12 2019, 05:53 PM
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QUOTE(Superhawk996 @ Apr 12 2019, 03:32 PM) *

but I assume you are AWD given your location.


Well, it's April 12 and I've been watching it snow outside my window all day. I'll let you decide if your assumption is correct.. (IMG:style_emoticons/default/happy11.gif)

I didn't know what Gen1 etc. meant but yes, double row of ball bearings just like the 914. I would assume the factory trained mechanics knew to torque the hub properly when they did them. I know I did when I did them myself last time. I'm not saying they are wearing out prematurely because I don't know what the acceptable service life is defined as. I'm just saying they don't last nearly as long as every other car I've owned which is basically, forever.
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Superhawk996
post Apr 12 2019, 06:16 PM
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"I would assume the factory trained mechanics knew to torque the hub properly when they did them."

(IMG:style_emoticons/default/av-943.gif)

Now that's funny! (IMG:style_emoticons/default/lol-2.gif)

No offense to dealer Tech's. Most are great and diligent. However they are paid on flat rate more often than not. I've witnessed bearing hub nuts go on with the impact wrench and no more thought than that. Hard to blame them if under the gun and they don't get billed back for parts if the repair fails. Since bearings with too much pre-load won't fail immediately there is little risk of it coming back to bite them personally.

Gen 1 -- is simple bearing that presses into knuckle. Or trailing arm in our case. bearing pre-load is controlled by torque across the joint.

Gen 2 -- is bearing and hub as integral assembly - not meant to be disassembled; service as an assembly. These are very problematic in service since it takes knowledge to recogniize them 1st and 2nd to use the proper special tools for installation that only applies pressure to the outer race. Mechanics often unknowingly press in via the hub and that damages the bearing.

Gen 3 is integral hub and bearing assembly with mounting flanges. Bolt and unbolt. Bearing pre-load is typically established by orbital forming of the hub to the bearing controlling to a pre-determined deformation that holds the hub & bearing together as an assembly. These are often used on the rear of 2WD since there is no CV & axle assembly to hold the hub and bearing together. These are typically very very reliable and are the ones that hold up for life of vehicle.


So onto seals. Engineering seals is a whole field unto itself. Single lip seal, double lip seal, with or without Garter spring. With or without an external Flinger?

Seals are designed with a bit of springiness to hold them into the bearing. After the 1st assembly at the plant, that is supposed to be it. Pulling the seals and then reinstalling them means they go in with just a little less spring force and a bit less of a seal to the outer race than they originally had. Minimal . . . yes. However, there will be just a little bit less sealing force to the outer race than it had initially none the less. We won't even talk about the potential for bending the seal slightly.

Likewise, in the case of lip seals (especially double or triples) it's easy to get a lip folded over. That will wear out the folded lip in short order and fail. I've even seen single lip seals fold. Again, minimal risk but I assure you it can happen.

Seals are what keep the water and dirt out. You could have the best bearing steel, the best manufacturing tolerances, and the best grease but if a seal lets in dirt & water, it won't live as long as it otherwise would have.

This is why I cringe seeing the bearing seals pulled for a little look see, just to be sure.

Aftermarket bearings are typically made to a lower standard than OEM and they cheap out on seals, grease, and steel quality.

So your best chance is with the bearing delivered with the vehicle. I've had several vehicles go to 200,000+ before a bearing went south. And that is inclusive of Michigan winters + salt + lots of corrosion. On the other hand I've had the OEM bearing fail at 90,000 miles and then had to put aftermarket on for tail end of the vehicles life when a $300 OEM bearing would have been 1/2 the vehicles value.
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Superhawk996
post Apr 12 2019, 06:35 PM
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(IMG:style_emoticons/default/happy11.gif)

Not done yet.

Bearing pre-load, or clamp load if you will, is not so simple either.

When you torque a fastener (I'll call it a joint) what you are doing is stretching the fastener like a spring. Let's call that force - clamp load.

Clamp load is interdependent on torque.

The problem is that torque varies greatly depending on the nut tolerances, the plating type (black oxide vs. Zinc for example), whether the fastener is lubricated, etc.

The joint clamp load needed is usually determined by lab testing and/or vehicle durability testing and/or past design history of success. However the OEM establishes this with new fasteners with what ever lube would be on them from the fastener manufacturing process.

So in the end, they are trying to achieve a certain clamp load is roughly equivalent to a certain torque using the fasteners as they would be in the factory new condition.

Now, let's go to two extreme cases:

1) A heavily corroded fastener. I think we've all been there. It takes a lot of torque just to run the fastener down. That torque although high, isn't converted to clamp load. It's lost internal to the fastener as friction. Worst case, the bearing gets very little actual pre-load. That will lead to short bearing life.

2) Now put grease or maybe anti-seize on the threads of a new fastener that is maybe a bit on the loose side of manufacturing tolerance or maybe a used nut that is loose from having been on & off a dozen times (like a 50 year old 914 Hub nut?) Fastener now goes on with very little torque to turn (not much friction). Now when the torque spec is applied more of the torque is turned into effective clamp load. Clamp load is much higher, therefore bearing pre-load is higher. That will lead to shortened bearing life.

Case #2 is why many new cars have hub nuts that are stamped - DO NOT REUSE. They are often have what is called prevailing torque fasteners (self locking). Lack of a castle nut and cotter pin is a clue that is probably is torque prevailing and single use only. Once they are used once, they will have lost their initial tolerances and "bite" on the threads. They will go on easier the next time, establish more clamp load, and will not effectively serve the locking function. How many times do these fasteners get reused? More often than you would want to know because a Tech may not know or may not care and just want to get the job off his hoist.

Anyway . . . moral of the story is a bearing's life (or lack of it) isn't easily written off as not enough grease as many would have you believe.

Sorry for the dissertation. (IMG:style_emoticons/default/sad.gif)
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mepstein
post Apr 12 2019, 07:34 PM
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We hired two techs from Honda. I don’t think they even owned a torque wrench. Everything was installed with the rattle gun.
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bbrock
post Apr 12 2019, 10:03 PM
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Good info. Might be true about Honda techs but we can't blame them for my experience because the bearings they put in lasted at least as long as the ones the factory put in.

I wish you had been here when I opened my bearings. Would have been interesting to get your thoughts seeing them first hand.
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mepstein
post Apr 13 2019, 05:40 AM
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QUOTE(bbrock @ Apr 13 2019, 12:03 AM) *

Good info. Might be true about Honda techs but we can't blame them for my experience because the bearings they put in lasted at least as long as the ones the factory put in.

I wish you had been here when I opened my bearings. Would have been interesting to get your thoughts seeing them first hand.

We have a 2009 & 2017 crv. No issues yet. Odyssey went 275k without touching bearing or really anything else before it was rear ended for the third time and totaled.
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Superhawk996
post Apr 13 2019, 07:15 AM
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@bbrock

Brent, I just want to be completely transparent that I'm not targeting you personally. I have no doubt that that one of your bearings had less lube than the others. Nor do I mean to question your mechanical ability or personal integrity. Your build is by far one of the most inspirational on this site and your attention to detail is an example for all of us to shoot for. (IMG:style_emoticons/default/grouphug.gif)

There is a saying:
Arguing with an engineer is like wresting a pig in mud, eventually you'll realize the pig likes it.


(IMG:style_emoticons/default/piratenanner.gif)

My broader point in keeping this post going is that we all have limited time to focus on our projects. What we do with them is our own prerogative and we should all do what keeps us happy. My intent to the original post was to offer a perspective to the OP that bearings are in general pretty robust little pieces of hardware and that I personally wouldn't sweat them. Worst case is that one fails prematurely and we have to replace it. Things could be worse things in life.

As engineers we seek to design parts to a particular life cycle. Particularly the b10 life which is defined as:

"The measurement of the time by which ten percent of a population of a product will have failed. The term originates from the manufacture of anti-friction bearings, and is used to express the minimum lifetime of ninety percent of a given batch of bearings operating within speed and loading tolerances."

Whatever that life cycle is designed to be, the parts then have to be manufactured, and within that process, we shoot for six sigma capability which is defined as a bell curve, normal distribution where we want 99.7% of the manufactured product to meet the b10 life as produced. Getting rid of that 0.3% drives up costs exponentially.

Attached Image

The bottom line is that there will be some very low number of parts that don't meet the b10 life due to the process variation during manufacture. You very well may have had one of the 0.3% of parts that might fall below b10 life. Who knows for sure? I sure don't.

My broader point in all this was that ball bearings don't even need lubrication (IN THEORY). Lubrication just makes them last much longer and that the lubrication method is variable. Grease isn't even an ideal lubricant . . . ideally you would want just a light mist of oil continuously applied, especially at high shaft speeds. Grease generates too much heat and too much friction at high shaft speeds (talking 10,000+ rpm type speed here - not car axles). A nice oil mist is hard to achieve in practice in precision machinery and is impossible to have in a wheel bearing and would be incredibly maintenance intensive. Therefore grease is a pretty good compromise that lasts a long time and doesn't require much maintenance.

Going out to do some real work on the beast!

(IMG:style_emoticons/default/drunk.gif)







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mepstein
post Apr 13 2019, 08:37 AM
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I used to use light oil on the bearings of my track bike when I raced on the velodrome. Cup and cone campagnolo bearings. Spun forever.
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bbrock
post Apr 13 2019, 08:48 AM
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QUOTE(mepstein @ Apr 13 2019, 05:40 AM) *

QUOTE(bbrock @ Apr 13 2019, 12:03 AM) *

Good info. Might be true about Honda techs but we can't blame them for my experience because the bearings they put in lasted at least as long as the ones the factory put in.

I wish you had been here when I opened my bearings. Would have been interesting to get your thoughts seeing them first hand.

We have a 2009 & 2017 crv. No issues yet. Odyssey went 275k without touching bearing or really anything else before it was rear ended for the third time and totaled.


I think our 2006 was the last year for that chassis before they rolled out a completely redesigned model. The bearings were changed to what looks like the Gen2 or Gen3 @Superhawk996 described. I don't think my brother had any issues with his Odyssey either. Don't get me wrong. We love our CRV. Other than the rear bearings, over 260K of trouble free miles and it still drives like new.
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bbrock
post Apr 13 2019, 08:56 AM
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QUOTE(Superhawk996 @ Apr 13 2019, 07:15 AM) *

Brent, I just want to be completely transparent that I'm not targeting you personally. I have no doubt that that one of your bearings had less lube than the others. Nor do I mean to question your mechanical ability or personal integrity. Your build is by far one of the most inspirational on this site and your attention to detail is an example for all of us to shoot for. (IMG:style_emoticons/default/grouphug.gif)

There is a saying:
Arguing with an engineer is like wresting a pig in mud, eventually you'll realize the pig likes it.


(IMG:style_emoticons/default/piratenanner.gif)


No worries. I'm an ecologist which is just a fancy term for another pig who likes to wrestle. I'm not sure we'll get to the bottom of best practices for these FAG bearings though. (IMG:style_emoticons/default/beerchug.gif)
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