Greasing Chevy sealed wheel bearings

[TX-Trek]

SKF hubs BR930352 - made in Mexico. Aside from the boxes looking like they had been dropped out of a plane, I didn't see any signs of damage or that anyone had tried to install them before. First thing I always look for.

ABS harness looks fine - the attachment for the sensor is just a plain old Allen bolt and I can see some blueish grease squeezed out at the sensor, seems to align with what Greaser had noted about using the blue Kendall L-427 grease. I'll pull the sensor and take a look inside. Only a guess but I wonder if these might actually be packed full. Would be nice.

The Wagner SX784 front pads and SX974 rear pads (severe duty semi metallic) are also made in Mexico as is the GM 24236933 transmission filter. Honestly I don't recall an issue with this mfg location before. These are the same pads as are on the van, I'm just replacing them after a few mountain incline battles. I'll get a clean up on the rotors, older local guy does a great job.

GM hubs country of origin is China, Timken can pretty much be anywhere, as can SKF. My "hope" is that any if these would be made to a higher standard than no name eBay stuff. Your opinions are welcome!

[TX-Trek]

I pulled the ABS sensors out of the new hubs, there's some grease in there but I'll definitely add the Kendall lube before I install them.

Edit... I poked around my hardware bins and found that an old oil pressure fitting and nylon tube lets me add grease to either side of the reluctor wheel and right up to each bearing. The fitting threads right onto the end of the grease gun tube.

[TX-Trek]

Just some grease info....
As mentioned I'm using Kendall L427 grease in the new hubs. I also have Valvoline Cerulean #2 grease in the gun, I use it for bearings, suspension lube etc.
After some product data research, I believe that either grease will do for the hubs.
Aside from being the same color, both are NLGI #2 rated, both use a Lithium Complex base/thickener and share very close drop point temp, ball wear test etc. They are both generally categorized as high pressure, low water washout , high temperature rated lubricants.

[booster]

Originally Posted by TX-Trek

Just some grease info....
As mentioned I'm using Kendall L427 grease in the new hubs. I also have Valvoline Cerulean #2 grease in the gun, I use it for bearings, suspension lube etc.
After some product data research, I believe that either grease will do for the hubs.
Aside from being the same color, both are NLGI #2 rated, both use a Lithium Complex base/thickener and share very close drop point temp, ball wear test etc. They are both generally categorized as high pressure, low water washout , high temperature rated lubricants.

The whole grease selection choices are kind of like the engine oil ones, everyone has a different idea for them.


I spent my working life in manufacturing facilities and most often was designated as engineering support for the facility and equipment maintenance departments. These factories have many hundreds of ball bearings in equipment, from big ventilation fans to gearmotors to web handling rollers, to high speed instrument bearings. Some high speed, some low, some in hot areas some outside in Minnesota so could see -40*F to +120*F on the rooftop.


In many/most of the applications a normal lithium grease was specified by the manufacturers of the equipment for general purpose use, and in most of the cases it did work fine without excessive replacements required. Sometimes, however, the application just didn't hold up and would get repeated bearing failures. Things running in very hot or very cold areas were more likely to have issues, and the rooftop units that saw both could be horrible.



After trying all kinds of different bearing styles, we zeroed in on grease with the help of some of the bearing suppliers and a failure analysis company. Nearly every one on our early failures were attributed to lubrication film failure, even though they were greased regularly.



We found out with testing that for the high and low temp applications (our high temps weren't all that high compared to ovens and such) we could go the a low temp synthetic grease that would cover the full range as it was suspected that most of the damage was occurring at cold starts until the bearings got warm enough to allow the grease to work properly. The rooftop bearings went from failing in 4-6 weeks to 3+years which certainly reinforced the cold start lubrication theory. The inside in hot areas like a high bay ceiling at 125*F also extended the life nearly as much, so the lower temp synthetic was also extending the life even at higher temps.


I quickly changed all the assumptions I had about the benefits, or not, of synthetic greases after that. They are expensive though, so we used lithium in the places where we got acceptable life.


I think many of us are old enough to remember the old timer mechanics that said you should always drive you vehicle slowly for the first "X" miles or minutes if the temp was much below freezing to let the wheel bearings warm up so they lubricated OK. I think they probably were very correct in that.


I can't say for sure that a good lithium won't hold up as well as synthetic if van wheel bearings, though, as it would require a whole bunch of testing that is just not practical for any individual to do. My guess is that because the high pressure additives are a very important part so that a good lithium could probably outperform a poor synthetic, but a high end synthetic that is on the low temp rated end would probably outperform most any lithium grease, particularly at high and low temps in tough situations. Our hubs may see -30+ to 300+*F so wide temp range is probably a top consideration in our vans. When I cut apart our failed hub the grease that remained in the bearing was totally dried out and sticking to the races away from where the balls ran, not where it belonged. Since the bearings had failed, it certainly could be that the grease failed after the bearing due to the heat from failing, but no way to tell that without getting a failure analysis done on them.

[TX-Trek]

That's great info, thanks.

I've got the 2 greases here but not out of the question to still consider a synthetic version. As you mentioned though a good quality lithium base should work ok, part of this equation I think would include a regular maintenance check of the hubs.

The other part of this is consideration of compatibility with the grease already in the hubs from the mfg. Back in the earlier posts, Greaser had noted his observations with many hubs - he indicated that the Kendall looked the same as what had been used, with no mention about any failures related to using it, meaning mixing Kendall with what was already in the hubs. I don't know enough to say if a full synth is ok added to the hubs. It probably is fine , any info is appreciated.

Very interesting topic.

[booster]

Originally Posted by TX-Trek

That's great info, thanks.

I've got the 2 greases here but not out of the question to still consider a synthetic version. As you mentioned though a good quality lithium base should work ok, part of this equation I think would include a regular maintenance check of the hubs.

The other part of this is consideration of compatibility with the grease already in the hubs from the mfg. Back in the earlier posts, Greaser had noted his observations with many hubs - he indicated that the Kendall looked the same as what had been used, with no mention about any failures related to using it, meaning mixing Kendall with what was already in the hubs. I don't know enough to say if a full synth is ok added to the hubs. It probably is fine , any info is appreciated.

Very interesting topic.

The mixing of the greases is a concern, but I haven't heard of any issues with the hubs because of it to this point.


One of the biggest concerns is that at some point the greasing may not do much good because the bearings are dead ended in the hubs so the old grease can't get out to allow new into the bearing. It has been discussed about putting a grease zirk into the sheet metal cover on the inside of the hub and through the face of the outside of the hub, but my concern would be with keeping any drill shavings out of the hub and bearing as that can be a quick death for a bearing.

[TX-Trek]

Agreed that trying to install a zerk may be a very bad idea. I think for this purpose, the nominal addition of the Kendall L427 should be ok to hopefully extend the life of the bearings. The hub operating range is within the grease working range, fingers crossed that as existing and new grease heat up they will both combine to provide more available lube to the bearings.
Wish I could see the internal operation and lubrication at road speed lol.

[TX-Trek]

Well this may be heading into an infinite detail rabbit trail, but I'm very curious about what grease is actually used in these SKF hubs. I snagged a bit of it and it's sort of a greenish yellow color. Looking thru the types of SKF greases there's one with green color that's lithium based but shows as biodegradable. No way I can say that's what's in there so I decided to contact SKF to ask.i doubt that they would use that type for sealed hubs.
I think the Kendall and Valvoline grease would be fine, especially for the oem hubs that will be replaced and kept as spares. I'll see what I can find out.

[TX-Trek]

Upon further investigation, per SKF they commonly use their GHG series (or updated equivalent) in automotive series wheel hubs/sealed bearings. This a mineral based/lithium compound grease with overall NLGI #2 rating.

Interestingly enough, the oem delco hubs are cast with "SKF GU" in the ID numbering, so safe to assume they are SKF hubs. They were not dry, and the grease did have a blue-green hue to it. The new hubs have "SKF DE" cast into the numbering and are also stamped with a mfg date of 4-1-2022.

There is a good amount of data published by SKF on the type of grease and the mount used for different bearings. For the wheel hubs they typically use a 30-50% fill, I suppose based on the hub bearing specifications, which can be an entirely other story.

As mentioned before, the Valvoline Cerulean #2 has almost identical specs as the Kendall L427 grease. Since I still had almost a full tube of the Valvoline, I decided to use it and return the L427 as I didn't want to have a tube sitting in the gun forever.

I did 4 pumps per side of the reluctor wheel on the removed oem hubs (8 pumps total for the hub), using the small oil tube gizmo per the pic in a post above. I could definitely feel a slight additional stiffness turning when I did this but smooth turning. No grease seeped out from the seals. I suspect that as Booster mentioned, there will be an initial turning resistance followed by a decrease as the grease is worked into the bearings. Remember these oem hubs are just going to be saved as spares, they seemed to be ok. This is just preventive maintenance since it's my "free" labor, just the cost of parts. And I'm prepared to change one on the road if needed.

I did the same grease addition on the new hubs, just adding 3 pumps per side of the reluctor (6 pumps total for the hub). I didn't really feel much of a change in turning resistance. I thought this was a safe amount to add without risking heat expansion of the grease through the seals. There was plenty of space left in there, nowhere close to the top of the reluctor. Obviously this is a trial to see what happens - in this case nothing happening will be just fine.

Without trying to sound like an SKF salesman, I liked the high-quality finish machining of the hubs, front and back. Threading is precise and well cut. Wheel studs are coated oem quality. Of course the real story is how well they will work.