I’m not really talking about packing the bearings themselves, but how much grease do you pack into the hub or put on the spindle when you’re putting the hub back on? I’ve heard guys say everything from almost none to pack it full, and I’ve heard arguments for both sides. Just looking for a bit of an informal poll.
I just pack bearings very little extra grease, but some extra.
I Pack them full.the more the better.
More grease is never the right answer. Overgreasing can actually cause the rollers/balls to slide over the bearing surface rather than roll over them. Also too much grease creates a churning effect which raises operating temps and cooks the grease allowing the thickeners to separate from the oils leaving only the non-lubricating thickener where lubrication is needed.
Packing the bearing and coating all the races in a thick coat of high quality grease is what is prescribed for every greasable bearing on the market.
My trailers have all had the spindle with the zerk on the end. What has worked for me is when starting with new set of bearings/races is to pack the bearings, coat the races and add a thin layer of grease to the spindle. Once everything is assembled before the final torquing of the nut, I pump the hub full of grease until it’s being forced to the outer side of the hub. I then adjust the nut to the proper torque and install the dust cap.
Again, this is what has worked for my style of spindles.
I pack them as full as I can. I’m not trying to totally fill the inner hub, but I really coat the bearings and then pack grease against the outside of the hub as much as I can.
I’m NOT doing this to try to get more grease on the bearings for lubrication. I’m using grease as a barrier to keep dirt, water, and grit away from the bearings themselves as much as possible.
You can certainly go the minimalist route and those that do are correct in that only a little bit of grease is strictly required as a lubricant. The problem is that boat trailer bearings IME almost never fail from lack of lubrication. They fail because they are immersed in rust-causing water that contains sand and dirt. It’s these contaminants that cause the bearings to fail, NOT lack of lubrication. Anything I can do to keep the contaminants at bay is worth the extra grease.
I’ve taken apart utility trailer bearings that hadn’t been serviced at all in 20 years and they looked BETTER than my boat trailer bearings look when I overhauled them every 2-3 years. It’s the immersion in water and grit that kills trailer bearings. If we didn’t get our trailers wet, the bearings would last forever.
Grouse
Im with Grouse, use grease as a barrier. Grease is cheap.
Service bi-annually, repack, new seals and maybe bearings if needed.
Full but not packed to the brim full. Exactly like Grouse says and it’s worked great. Everyone has their opinions and not a single one is necessarily wrong. There are positives and negatives to each preference…
So, what do bearing buddy’s do????
None. My trailer has greaseless bearings.
December 4, 2018 at 8:40 pm#1815135
More grease is never the right answer
Munchy hit the nail on the head. Too much grease causes excessive heat. If you are driving 2 miles to the lake and back its no big deal. On a longer trip you could have issues. Using grease to keep water out isn’t the answer. Any water and all of the grease is contaminated and will cause the bearings to rust and or corrode. Using quality parts –especially the best seal you can buy to keep water and dirt out is the key. As is periodic inspection to check for grease that is discolored by water. My trailer hubs use oil instead of grease. They have a clear cup that holds it so you can see if its contaminated. This type runs much cooler.
I have a Shorelander trailer with the grease zerk in the end of the spindle. You pump in grease till it starts to come out around the nut washer. I give it a couple pumps a year and good to go. I learned this the hard way and smoked a bearing on a trip because I could never get any grease in the hub due to a bad end on my grease gun. New grease gun and Amsoil boat grease, good to go.
So, what do bearing buddy’s do????
They keep grease packed into the hub.
More grease is never the right answer. Overgreasing can actually cause the rollers/balls to slide over the bearing surface rather than roll over them. Also too much grease creates a churning effect which raises operating temps and cooks the grease allowing the thickeners to separate from the oils leaving only the non-lubricating thickener where lubrication is needed.
Packing the bearing and coating all the races in a thick coat of high quality grease is what is prescribed for every greasable bearing on the market.
You clearly have some technical knowledge of bearing and lubrication. I am also familiar with this concept but I think it applies to more so to high speed applications. Wheel bearings are relatively slow speed. The viscosity of the oil will have a bigger impact on temperature than over greasing.
I think the only risk you run by packing them full is the seals blowing out from thermal expansion. Otherwise, packing bearing cavities full of grease is a common practice to displace water.
Where I work, we pack bearings in our parts 100% full in -40 environments to displace water so it cannot freeze in the bearing cavity causing high torque.
<div class=”d4p-bbt-quote-title”>roger wrote:</div>
So, what do bearing buddy’s do????They keep grease packed into the hub.
Bearing buddies maintain a positive pressure in the hub so water doesn’t come in. This all goes to hell if the pressure is lost or if the bearing buddies are overpressurized.
Don’t know right answer but 20 or so trips to Flin Flon packed bearings as full as can get, never had a problem.
There is really no wrong answer here, everyone has their own technique and if it works, it works.
The important thing with boat trailer bearings is regular maintenance. No matter how well your hub is sealed, or how much grease is in it, regularity putting it in the lake will eventually lead to contamination.
I personally put a lot of miles on my trailer (240 miles one way to the cabin) so I pack them each spring and check them before each trip.
The biggest issue I’ve had is putting my boat away in fall with a small amount of water in a hub and having rusted bearings come spring.
So I now do them twice a year, fall and spring, grease is cheap.
If you pack your bearings in the fall and store it you won’t have to pack them in the spring. Did this for at least 25 years and never had a bearing/axle problem. Made many 6 to 16 hour trips too.
If you pack your bearings in the fall and store it you won’t have to pack them in the spring. Did this for at least 25 years and never had a bearing/axle problem. Made many 6 to 16 hour trips too.
It works for me. My boat doesn’t necessarily sit all winter either, usually make a few trips to pool 2 and 4 in February and March.
Like I said everyone has their own system, maybe I over due it, but I’m not gonna be “that guy” if I can help it.
I hadn’t looked at my boat trailer bearings till last year. That’s at least 7 years without a look, is that right Iowaboy1? Makes me a believer in my setup.
Oil bath hubs! Lol!
You betch’a baby! I’ll never go back on a boat trailer.
Ranger – oil bath hubs! I carry a seal, tools, oil on long trips, trailers with old school grease , repack yearly, give a shot or two mid year
I can attest to putting (way) too much much in. Fortunately I saw the grease on the inside of the fender right away (courtesy of a blown inner seal) before any real damage occurred.
Now I inspect them each spring (my longest drive with it is going to Kab for opener) and repack then put in grease just till I see it start to push out the outer bearing, out right replace them every third year. Maybe overkill but a bearing set is a lot cheaper than fixing one one the road I figure. I rotate the tires each spring too (both and spare), mostly so the spare actually gets used, I’m sure it extends their life some too.
I hadn’t looked at my boat trailer bearings till last year. That’s at least 7 years without a look, is that right Iowaboy1? Makes me a believer in my setup.
me first then Denny ha ha.
I fill the hubs on my trailer,biggest reason being as has been mentioned is keeping water out.
if the bearing pre-load is done properly the hub will never get hot enough to push grease or the seal out.
that said,even if the pre-load is done correctly and there is overloading,excessive brake drag for whatever reason,misalignment issues,bent axle or over/under inflated tires,improper grease,these things can cause overheating of the bearings and cause failure and the over filling of grease will be blamed.
grease is a very heavy substance that takes a tremendous amount of heat to cause enough expansion to push out past a seal or blow a seal out its bore,hot as in almost red hot.
bearing buddies,I have used them for years with no issues,now,I have seen where people pushed the seal out of its bore by over greasing,this was accomplished because the wrong seal for the application was used,ie,an oil seal instead of a grease seal,there is a large difference between the two.
a grease seal allows air out,just enough that grease will weep out of them when a bearing buddy is over used.
a grease seal will not let water back in,if a bearing is loose where the seal is not sitting square on the shaft,then yes,water will creep back in.
an oil seal most often is spring loaded to keep constant pressure on the seal face and it will also hold a bit of pressure,this is where a bearing buddy will build enough pressure to push it out when the two are combined and someone gets over zealous with a grease gun.
an oil seal also has a second sealing lip that keeps debris of whatever origin away from the primary sealing lip to protect it for long life service.
for those of you that do your own bearing service,check the bottom of the axle where the bearing rides as it can be undercut and the bearing will not pull up square with the axle when its tightened up,this causes misalignment issues between the inner and outer bearing and the seal wont ride true on its surface.
this is especially true with the inner/larger bearing.
if you have redone your bearings and still leak grease past the seal or the bearings/hub run warm this is most likely the issue.
use a good grade of grease designed for wheel bearings and dont use the cheap sh!t either.
if new bearings are in order,dont buy cheap sh!t bearings,timken if you can find them for your axle,so what if they cost six bucks more,a tow truck service will cost way more than that when you are broke down on the road !!
make sure you have the correct seal for your hub and axle.
pre-load the bearings properly once greased,spin the hub as you creep up on the pre-load to push excess grease out from in between the roller and race,and remember a tiny bit loose is better than a tiny bit tight if the keeper/cotter pin doesnt line up exactly as it should.
I hope I covered most of it !!
Denny O
that set up on your trailer is really slick,literally,its not often you have to put grease in the freezer to make it solid enough to pack the bearings.
the grease in that type of axle is semi-fluid at room temperature for those that dont know or have never been around it,perfect for cold weather service!!
the biggest reason we had to service them was one,it was at the recommend interval,and two,grease was escaping a seal.
this was due to a disc brake caliper that had seized causing enough heat to be transmitted from the rotor to the hub and melting the seal lip,
an extreme case if I ever saw one.
it had caused enough force to be applied to the caliper bracket that it had egged the brackets bolt holes out!!
a bit of welding and re-drilling of the holes took care of that in short order.
then there was all new brackets,calipers,brake pads,bearings and seals for all four corners !! what a day we put in !!
I still savor the bottle of thanks that day Denny !! Jack single barrel,first bottle I had ever tried,ssssmmmmmooooooooooootttttthhhhhh !!
now if I could wave a magic wand to get it to refill itself every other week,sigh.
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