So, I just purchased a set of New FAG wheel bearing (made in Germany) so I can install a set of the later (74-89) 911 rear hubs on my 914 control arms.
I saw a few you tube videos about how the bearings for the Boxster where being shipped with little to no grease in them. I figured before I install them to check the grease. Well sure enough one side had little grease and the other side had very little to no grease on the bearings. I should've taken a few pics but didn't have my phone handy. I still have another new bearing to inspect so I'll take pics of that one. I'm sure it will be the same way. Now to go pick up some grease and repack them.


So if anyone of you out there plan on replacing your rear bearing I would inspect them.

Here's a handy video which shows how to do this.

https://www.youtube.com/watch?v=l9P1R2clGAU

Luke,
Are those the ones I sent? They were old stock and I did not even think about checking. Those bearings were from the 1990's.

I’ll check mine before I install. They need grease but not so much it packs the bearing full.

Hi Mark,

Yes, the ones I just got from you. I'm guessing it's been an issue for awhile now. I'll pull the other bearing apart tmrw and post pics.
I just removed my old but new never run bearings.
I'll pull those apart too to see if there's grease in them.

Don't want to rehash this whole topic. Brent and I had a good conversation on the state of bearing grease just a month or so ago.

Bottom line - you'd be surprised how little grease it takes to keep a bearing happy. You will never find a bearing fully packed. Don't get me wrong. Dry is unacceptable but over packing is just as bad.

http://www.914world.com/bbs2/index.php?sho...7290&st=720

I now wonder how much is ENOUGH.

That is the question isn't it.

The pictures that were posted in Brent's pages of the original grease pack was enough. They had grease on the cages but were not "packed".

The grease on the cages will distribute itself onto the balls and the race when it gets warm and has centrifugal force that will fling it radially outward bearing races.

As previously mentioned, the grease shouldn't be waxy if NOS bearings. As long as it has that viscous petroleum grease texture it will be OK.

Improper bearing installation technique is a lot more likely to lead to premature bearing failure than a light load of grease.

Again to avoid inflaming folks. No grease is not acceptable but it really does take a lot less that most of us think is necessary.

My advice is to trust the bearing manufacture's grease type and grease load. Any quality manufacturer (SKF, FAG, NSK, Timken, etc.) spends a lot of time to figure out what the right load is. The aftermarket bearings usually just copy what they find on OEM parts knowing that the OEM did the hard work and the development testing.

I wondered after seeing the boxster video if it wasn’t because the guys seemed to take the car out of the trailer and immediately get it up to speed on the track. In contrast to a road car being driven at slower speeds for a while before it’s ever cornered at high speed. We’ve replaced dozens of rear wheel bearings at the shop and haven’t had any come back with issues. Just a thought.

The other thing that I noticed with the grease is that it was chunky. The grease may have just deteriorated with age? These are new but old stock bearings.
I looked at Brent's post. His bearings had by far more grease in them then these.
It could be that with age (now 20 plus years) that the grease just broke down.
I will tear into the other bearing today and post pics of the findings.

You have to scroll down to the second one I opened to see the bad one. The first one I opened had what looked like an adequate amount of grease. It was unevenly distributed, but both bearing races had enough grease to be lubricated while the grease redistributed itself from use.

The second bearing I opened (same manufacturer purchased at the same time) was a different story. One side of the bearing was completely bone dry without even a hint of grease. The other side had such a small amount that there is no way it would have been enough to lubricate both sides, and even if it was, one side of the bearing would have run dry for some time before the grease redistributed. I'd say that bearing had maybe 1/5th the amount total as the first bearing.

From what I saw, there is absolutely a quality control problem with these bearings and I wouldn't trust that the manufacturer is greasing them properly. There shouldn't be huge differences in the quantity of grease from bearing to bearing.

Bearings don't need much "lube" to run for long periods of time especially if the loads are light and they are light in road going vehicles. Race cars pulling high lateral G's for long periods of time are another story.

What kills bearings the fastest are things like vibratory loads and false brinelling. False brinellling can easily occur on race cars that are tied down too tightly in trailers and then proceed to vibrate or oscillate the bearings with no rotary motion.

https://www.ntnglobal.com/en/products/care/...e/fretting.html

Any reputable OEM has pretty good quality control checks in place to ensure grease is put into the bearing. More applicable to new bearings. NOS predates my involvement with the bearing suppliers. Grease flow meters are built into the line. Bearing won't move to next station and/or line stops if flow meters don't register grease injection. Vision systems look for presence of bearings, cages, and grease otherwise no-go. There may even be a visual check by a real human prior to seal installation.

still can happen though but it is rare.

Bad information on interwebz (including me - ) is statistically more likely than a mainstream OEM kicking out thousands upon thousands of bad bearings.

Food for thought.

The other thing to keep in mind for you guys tracking vehicles or racing is that high lateral G's for sustained periods are typically outside the production vehicle operating envelope (including Boxter's and 911's).

High lateral loads force the load in the bearing raceway diagonally upward on the bearing race vs. the normal downward force from gravity. This puts more pressure & load on the thinner portion of the bearing raceway up near the square edge.

In extreme cases, the ball to race loads can be moved up high enough that you'll begin to deform the raceway and this begins a death spiral of pitting and material deformation in the raceway and debris circulating in the bearing.

Bottom line - bearings are a consumable item if racing. Do proper maintenance before failures occur. Higher temp grease will help delay this but it will eventually occur due to the way the load is being applied up high on the raceway and for the extended duration that it is applied during racing or track use that the bearing wasn't designed for.

See video below at the 0:56 second mark. Note how high up on the raceway the damage is.

https://www.youtube.com/watch?v=-A5kf5pXl4w

You're a real Woody Woodpecker... a trouble maker.

All I can speak for is what I saw. I opened what should have been two identical bearings and found significant differences in the amount of grease inside. I agree about not trusting what you find on the Interwebs, but what I found with only two bearings fit perfectly with what the "Interweb experts" were saying.

In the video you posted, you'll notice the guy who opens the bearing says that one actually looks pretty good but has more grease than other ones he opened which indicates he's seen the same variability I found in only opening two.. My first bearing I opened had about this same amount of grease and i also thought it looked okay. But the second one, no way.

The vid in the original post is a good tutorial on opening the bearings, but I would say the bearing he opened had adequate grease. It seems to me the area he points out with "no grease" would have been lubricated after the first few rotations of the bearing. On one that I opened, one whole side (bearing cage and race) was completely dry and I think there is a good chance you could be driving at speed for some time before any of the stingy amount of grease on the other side found its way over.

Obviously my observation isn't definitive and I'm no expert, but from what I, and others have seen, I think at least a quick inspection before installing these bearings is time well spent.

And to think - I started off never intending rehash the topic to this degree.

Click to view attachment

In the spirit of Laurel and Hardy.


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

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.

That is an excellent YouTube video of a person pushing hydrocarbons across his skin and into his bloodstream. Sure, we’ve all done it. Not saying that I have great knowledge about nitrile gloves from hf, but I sure use them. Oily chemicals cross the skin fairly well.

This is probably a dumb question but it’s not my first, i installed new bearings in the rear a couple years ago and the cars been riding its jack stands ever since. Is it possible to check for grease after installing them? Or do anything about it if there dry?

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.

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.

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. Click to view attachment

John

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.

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.

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.

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.

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..

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.

"I would assume the factory trained mechanics knew to torque the hub properly when they did them."



Now that's funny!

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.

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.

We hired two techs from Honda. I don’t think they even owned a torque wrench. Everything was installed with the rattle gun.

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.

@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.

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




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.

Click to view attachment

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!

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.

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.

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.