At the beginning of the season and every 5000 miles. My preference.
I flush out the bearings using the Zerk fittings during de-winterization and every 2,500 miles. I also remove, inspect, and hand pack every three years (refilling the hubs after assembly. (I know the manufacturer says yearly - overkill if you flush the hubs with grease every 2,500 miles)
Last time I checked them they looked brand new and hubs can easily be held in the hand after 4 hours of highway driving.
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Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
I flush out the bearings using the Zerk fittings during de-winterization and every 2,500 miles. I also remove, inspect, and hand pack every three years (refilling the hubs after assembly. (I know the manufacturer says yearly - overkill if you flush the hubs with grease every 2,500 miles)
Last time I checked them they looked brand new and hubs can easily be held in the hand after 4 hours of highway driving.
Could you define "flushing out"? I probably need to do some bearing work but but have been nervous of blowing out a seal or overfilling and getting grease into my brake drums from over pumping at the Zerk. I probably have 2 1/2 years and 4k miles on my current bearings with nothing other than added grease.
Could you define "flushing out"? I probably need to do some bearing work but but have been nervous of blowing out a seal or overfilling and getting grease into my brake drums from over pumping at the Zerk. I probably have 2 1/2 years and 4k miles on my current bearings with nothing other than added grease.
Added grease is what I was referring to. I use a hand grease gun (no air or electric) and slowly pump just until the black grease is replaced by the clean red and then stop. (This is just the dirty grease from the OUTSIDE bearing initially. It will be a short push until the INNER bearing's dirty grease works its way through to the outside; then there will be quite a bit of dirty grease as the hub's outer race flushes out till fresh red shows up again.) See the graphic.
It should go in easy. If it squirts out the side or won't take grease with an easy pump, the Zerk is plugged and needs to be removed and cleaned or replaced. Trying to force grease into the Zerk will over pressure the hub and you risk seal damage.
Removing the hub to repack the bearings by hand can actually increase the risk of a damaged seal if the seal surface comes in contact with the axle's threads; scoring it.
I have found that using the EZ-Lube (or Ultra-Lube) system regularly, reduces the risk of seal damage and increases bearing life. Obviously, your experience may differ. Not promoting it; just saying you paid for it when it was shipped with the trailer, so you might as well use it.
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Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
Herk thanks for that description. I was trying to figure out how to hook my air compressor up and envisioning a big greasy mess in my pole barn. I did that this spring. Pumped the new red high temp (don't have brand right now) in black old came out when red was coming out figured I was good. Leaving next week for maine from Michigan so I may give a quick squirt before we go as I did take one 50 mile trip last week.
Hey Herk, do I need to remove the wheel to lube from the zerk and will the grease come out the front by the zerk or out the back toward axle?
No, in fact leaving it on will help you spin the wheel. While not "required," it is an accepted technique to jack each tire till you can spin it and slow pump the grease while it is spinning. The idea is the new grease will fill the rollers better.
As to the grease coming out, it had better come out the front around the axle nut. That is how the system works. See the graphic. Messy I know, but so is packing the bearings.
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Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
Perfect, thanks Herk. I am always afraid of getting grease where it shouldn't be. I typically have the bearings repacked every 2 yrs because I typically have low mileage.
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2012 F350 Lariat CC SRW 6.7L Powerstroke
Perfect, thanks Herk. I am always afraid of getting grease where it shouldn't be. I typically have the bearings repacked every 2 yrs because I typically have low mileage.
Much past that and it will certainly need a repack. The grease used in the EZ/Ultra-Lube systems tend to solidify over time if not regularly pushed out.
Once it cakes up it is almost impossible to push through the bearings. Most stories of blown rear seals are folks trying to use the system LONG after the bearings need to be cleaned and inspected.
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Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
Hey Herk, do I need to remove the wheel to lube from the zerk and will the grease come out the front by the zerk or out the back toward axle?
Some of the newer models are coming with a center cap held on by the wheel. Mine is one of those so the wheel needs to come off to access the zerk. If you're not 100% sure I'd remove the first tire to check before attacking it with a mallet & screw driver.
Some of the newer models are coming with a center cap held on by the wheel. Mine is one of those so the wheel needs to come off to access the zerk. If you're not 100% sure I'd remove the first tire to check before attacking it with a mallet & screw driver.
MTB
Picture please. Mine uses the center rubber insert to access the Zerk.
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Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
Picture please. Mine uses the center rubber insert to access the Zerk.
First off, thanks Herk for the info! A couple questions though before a run out and get some grease. How much does this usually take to get to new grease and how are you getting the old grease out? I assume you are just pulling it out with your finger as its filled with new grease.
Thanks again!
First off, thanks Herk for the info! A couple questions though before a run out and get some grease. How much does this usually take to get to new grease and how are you getting the old grease out? I assume you are just pulling it out with your finger as its filled with new grease.
Thanks again!
DO NOT use your finger! That hub is sharp! (Don't ask how I know)
How much grease is harder to answer. It depends on whether the hub is full now, or they just hand packed the bearings and left the hub empty. (My case)
If empty, it may take several full pumps of a large tube manual grease gun to even get any motion at all. (In fact you may even worry it is going right into the drum!) But after a bit of slow pumping you will see motion at the bearing and the packed stiff grease (typically gray icky color) will start to ooze out. keep going until you see the red (if you use red) new grease come out. Now your hub and bearings are filled.
If they are already filled and you are just flushing the bearings, only a pump or two is needed to completely push the outer bearing dirty grease outside; and you can stop. (The inner bearing grease will be pushed into the hub).
Since you will continue to do this several times, there will eventually come a time when that dirty inner bearing grease will contact the outer bearing when you pump, so it will take a long while to push all the dirty grease out and see new red grease.
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Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
Linear Mode
