just bought spare hub 4 1/2x5 with all bearings and grease seal at red neck trailer supply for $78.16 including tax.Good to have a spare.

Mystic JT-6 Hi-Temp red.

I have just finished reading this entire post. Very interesting info, however, I have a 2000 Ranger w/dual axle Rangertrail trailer with the Cool Hub system. Although there were several posts mentioning them, no one offered any advice as to service, replacing the oil, seals, etc. I have owned the rig for over 6 years and have never changed oil or serviced them in any way. I could call Ranger boats for help but thought others on this sight may have experience and perhaps could offer some suggestions. I also have brakes on the rear wheels on the trailer and have never checked them either. Should they be replaced periodically as with vehicles? My normal trips are 45 to 65 miles (one way) and fish 10-12 times per season. Any suggestions would be appreciated.

Where can you purchase Mystic grease?

Can one of you guys explain what the cool hubs are? I've got a 07 Triton 21X2. The sales rep told me as I picked it up to just look at the clear hubs and if the color was anything but black, to bring it in immediately. Unfortunately if I get a wrench or screwdriver in hand, somethings usually about to break

Cool hubs are filled with oil versus grease. I am not sure what kind of oil. The problem that I see with them is if you ever have a seal blow than you will lose all lubricant.

i bought my first bass boat about a year and a half ago (used) i was so excited, my dad owned a boat shop for 10 years and before i left for the lake he said you need to check those bearings. being 22 years old i didnt listen to him and just left. Drove about 3 hours away and when my buddy bumped my boat into the water and pulled up i looked down and my wheel was floating in the water. the bearings were in pieces and the only thing holding the wheel on was the weight.. it was a sunday in a small town and i had limited tools. needless to say i learned my lesson and my bearings are checked every 6 months

Walmart and Academy carry bearings made in china. I learned my lesson the hard way using cheap bearings made in china. Never again for me. I only use Timken or NSK bearings and Mobil 1 synthetic grease with double lip seals. I have been hand packing my own bearings over 25 years. I have learned to never trust anyone that says, "the bearings have been packed recently..." on any trailer I buy. Always pack your bearings yourself or watch someone pack them for you.

Great information in this post. A few years back, I had the bearings packed on my Ranger Boat trailer at a reliable shop. After traveling a very long distance, I realized within a few hours from home that one of the wheels was coming off my trailer. When I inspected the situation, the bearings, hub, spindle were welded together. Had to have the boat and trailer put on a wrecker to take it to a shop two miles away. They had to replace the axle. I was lucky the wheel did not come off while on a major interstate highway. The shop paid my expenses with no problems. I used to pack my own bearings. I have had the various shops pack them since this incident. However, after reading this post, I am going back to packing my own and carry a spare hub with me.
Thanks for all of the valuable information. This is a subject that needs to continue. Very worthwhile information.
And, by the way, the hand packing procedure from the person in San Marcos is the procedure my Dad taught me.

I have seen plenty of good advice in this thread, but also plenty of anecdotal evidence to support claims that aren't really based on science. Just because your trailer didn't fail yet doesn't mean your methods are sound. If you used your methods on 100 trailers, how many would fail over a given time period... that's the measuring stick. I could say I have never worn a seat belt and I am fine after so many years, but then that would not prove that wearing a seat belt isn't conducive to staying alive.

I don't think bearings or spindles get hot enough to generate steam when submerged, at least healthy ones do not. That doesn't mean that they don't contract when cooled, but the degree difference between a 120 degree instant cooling and a 20 degree instant cooling is substantial. Still, there's no reason to not allow the hubs to cool. I have found that my hubs are never as warm as my tires, even in the Summer (especially in the Summer).

I have had bearings fail, and what I have found is that, at least for those two events, it was more about the relationship between the spindle and the races than the grease. There was still plenty of grease, it flew all over my fender and wheel, but the bearings were gone. Grease will not stop incompatible parts from coming apart, and compatibility is tolerance. Some of the brands mentioned are more compatible to precision spindles than others that are just mass produced in China.

I think we all know someone who has lost a hub or spindle with a relatively new trailer. I know I do. You have to wonder what happened there, was it a lack of grease or did the trailer get assembled improperly? Or was it just a tolerance issue between the parts on that wheel, luck of the draw if you will. Then again, how did the owner treat the trailer on the road? Did he slam across tracks, speed bumps and pot holes? All that can be rough on spindles, since all we have are leaf springs (unlike our trucks that have shocks and a much better suspension than our trailers).

I am going on 4 years without opening my hubs. I do use the Bearing Buddies, but I don't add grease to them since I haven't seen any grease leaving them and the seals are intact. Is that the best way? I don't know, but my last trailer had two failed hubs and I was religious about the maintenance on them. Probably just more anecdotal evidence.

You know even if it doesn't show that you are loosing grease, I found the best way to make sure your trailer is safe to roll anywhere is to repack and inspect the bearings by hand every year in the off season when you are not using it so much. My rig rolls every month of the year, it never sits so inspection is important and hand packing is very important, always inspect for pits and wear. Also in a good note is to run your motor every month weather you use it or not and use stabil treatment for ethanol.

I just completed frying my bearings on the right side. If a fellow hadn't flaged me down I'd be on the side of the road with one wheel on.

I just bought a new axle and was told by the wholesaler that they didn't recomend bearing buddies. Said most folks keep adding grease til they push out the seal. Said to have the bearing repacked each year or two. I have no idea if he's correct but I'm pretty sure I was one of those that kept adding grease when I didn't need it. And had new seals and repacked 6mo. before the failure.

No sure if I'll put BBs on this axle or not, but it's sure hard to know what to do with these buggers.

On Bearing Buddies, I think they can led to a false sense of security. Just add grease and go. Had a boat shop owner tell me he sees it all the time. Guy puts to much grease in with the Bearing Buddies, it heats up, expands and blows out the rear sell. I hand pack mine for now on. Messy, but doesn't take long once you've done it a few times.

Had a fellow come out and put on my new axle, he is a hub and spindle expert and he said the same thing that Southwest said, you should repack them every year or so. He also agrees that the BBs give a false sense of security and beg you to put to much grease in them eventualy forcing out the back seal.

after reading this on bearings I realize I'm a dummy on bearings. My trailer has BBs and I always pump grease in every time I go to the lake ( 280 mile round trip once a month ) , the removeable insert ( cover ) is cracked or blown out and my wheels are drenched with dry grease,thanks for the info.