greasing trailer wheel bearings

tawilson · Apr 27, 2005

I've got 4 trailers(boat, snowmobile, dump and equipment) and would like to get up to date on greasing the wheel bearings. First, some of them have the zerc's on the grease caps. Is that adequate for lifelong greasing or do you still need to pull the wheel and get your hands dirty? Second, anyone care to give a quick run through. I used to do it at my dad's trailer sales 25 years ago, but could use a refresher. Is it necessary to pull and replace the back grease seal, or is just pushing the grease in with the fingers enough?

Bird · Apr 27, 2005

Tom, I guess it depends on where those trailer hubs have been and for how long. One of my brothers had a 17' boat on a trailer in Alaska; used it both on fresh water lakes and in Resurrection Bay out of Seward. I think it was 4 years old when he moved back to Texas and brought it with him. It had the bearing buddies, so he could just hit them with the grease gun. However, when it was about 6 years old, we decided to take it to the Texas coast to go fishing and decided we might ought to pull the bearings first to see what they looked like. Good thing we did, too, because all the bearings and races were in bad shape, so we replaced everything. Personally, anytime I repack wheel bearings, I use new seals. You can't get the inside bearing out to properly clean and inspect it without removing the grease seal. You might replace the old seal and be OK, at least if the trailer doesn't have brakes, but if it does have brakes and the seal leaks, then you have a brake job to do, too.

So . . .,

1. pry off the cap (if it has bearing buddies, tap lightly around the outside with a rubber or plastic mallet to loosen and remove them),

2. then remove the cotter pin (I like to use a new one when I put it back together),

3. unscrew the castle nut, pull the wheel, or hub, outward a little bit, then push it back, and you can easily remove the outer bearing and washer,

4. I usually put the washer and castle nut back and jerk the hub off (that lets the washer and castle nut knock the inner bearing and seal out of the hub (some prefer to just pull the hub off after step #2, then pry the seal out),

5. Clean everything thoroughly in solvent, dry it all, and inspect for pitting or other damage, (if there is any, buy new ones),

6. Pack grease into the bearings,

7. Put the inner bearing into the back side of the clean hub,

8. Press or drive the seal in, being careful to keep it straight (I sometimes use a clean wooden block on it, being careful to not get any splinters or sawdust in the hub),

9. Finish installing in the reverse of the disassembly.

And, yes, it's a dirty job. /forums/images/graemlins/frown.gif

RedRocker · Apr 27, 2005

I'd do a repack like Bird said regardless of the bearing buddies. One of my trailers has them and after a few years it was due for a good repacking.

tawilson · Apr 27, 2005

Thanks Bird. Neat trick for getting the inner seal out. I figured prying it out would probably damage it.

Darellk · Apr 27, 2005

As a car mechanic in a former life I've packed thousands of wheel bearings. I found the greatest invention since sliced bread for doing it. It is a plastic bearing packer readilly available from a tool truck or maybe napa parts. Fill the container with a good quality bearing grease drop in the plunger. The top is cone shaped so you just wipe off the old grease on the bearing,place it in the packer, install the cone top and press down untill you see new clean grease coming out of the bearing. It is a huge time and mess saver. I can pack 4 bearings in less than 5 minutes and hardly get my hands dirty. I think the manufacturer is Lisle Tool.

tawilson · Apr 27, 2005

I remember that. My dad had a metal one. Thanks for the advice guys. As a reward, here's a link to one of the funniest clips I've ever seen. reptileattack

Bird · Apr 27, 2005

You mean sorta like one of these? I gave mine away when I moved back to town.

Alan L. · Apr 28, 2005

Since I have not had time to fix my trailer I took it to a trailer dealer where they are rewiring it, putting on all new lights, new boards, welding on a new bulldog coupling, and repacking the wheel bearings.

The trailer is 6 years old and I have never repacked the bearings, so I wouldn't be surprised if the bearings are shot. The mechanic told me they take them off, clean them up, and spin them with air. If they survive they keep them, bad ones will fly apart he said.

RedRocker · Apr 28, 2005

( Thanks Bird. Neat trick for getting the inner seal out. I figured prying it out would probably damage it. )

You need to replace it anyway, so pry away.

Egon · Apr 28, 2005

( Clean everything thoroughly in solvent, dry it all, )

Bird:

Many years ago we were given a talk on lubrication by a company representative. He specifically said not to use air to dry any bearing cleaned in varsol as it would affect the grease's ability to stay attached or coat the metal.

Egon

dullpain · Apr 28, 2005

Anybody that dry spins a bearing with air pressure to test I would be suspicious of the quality of their work, or of their knowledge of mechanics.

em14 · Apr 28, 2005

Well said!
Leo

tawilson · Apr 28, 2005

I don't have a problem putting in a new seal, but how do you know ahead of time what one to get? I figured I'd have to take the old one to NAPA to get the right one.

midlf · Apr 28, 2005

While you are getting the seal, get a spare one and a spare bearing, race, grease cap and a small tub of wheel bearing grease. Take the bearing, race and seal out of their packages and sink them in the tub of grease. You now have everything you need if you have a problem on the road. Oops - cotter key, washer and nut also. Write down the seal and bearing numbers so you can get them ahead of time the next time you need them.

leaddog · Apr 28, 2005

I saw a guy spin a timken bearing once with air. It will hit about 30,000rpm in a hurry. The race came off and it spun on his finger. Cut it all around down to the bone. They almost didn't save it.
Never never never spin a bearing with air aftercleaning it as you will scratch the rollers and the bearing is ruined. Every bearing manufacturer will tell you that and any grease monkey that does it isn't going to work on my stuff.
Leaddog

Jagmandave · Apr 28, 2005

I was going to relate a similar story, a buddy a work did a similar stupid stunt after I warned him not to. It not only tore up his finger but it flew off and went thru the windshield of an old Rolls Royce - cost the owner hugely to replace it. We were just glad it didn't go thru someone's head...... Moral - don't ever spin a bearing with air, it can hurt you real bad!

Junkman · Apr 28, 2005

I take this one step further and purchase a complete spare hub, which comes ready to be installed. I have found that buying the hub complete at the trailer sales yard is quite inexpensive. I had a new bearing and hub self destruct on the road, and it was only the fact that it happened in front of a salvage yard, that saved the day. They came out with a cut off wheel and cut the old race off the axle shaft. Hunted around town until we were able to find a bearing to replace the one that seized. They didn't have the seal or the other bearing. Repacked everything and tied a rag around the axle to act as a seal and drove home with no more problems. After that, I decided that a cold chisel, hammer, and the tools to install the new hub were in the tool box with the trailer. This happened to a new axle that made it 600 miles one way, and seized up 30 minutes into the return trip. I have no idea to this day, why it didn't happen on the original trip. Murphy's Law??????

Alan L. · Apr 29, 2005

Maybe they all fly apart when they spin them with air, so they get to replace them.....

I'm supposed to pick up my trailer tomorrow. Hopefully they haven't screwed it up too bad. Now I will be worrying that the bearings held up but are ruined by the air spinning trick /forums/images/graemlins/frown.gif /forums/images/graemlins/frown.gif.

JimR · May 1, 2005

Most parts stores carry bearing kits for trailers. They carry 3 different kits. One is the 1" inner and outer, 1 1/16" outer and 1 3/8" inner and 1 1/4" inner and outer. All these kits come with the seals. One kit does one wheel. The cost is around $14.95 - $19.95 per kit. I just did my dual axle 24' trailer for $80.00.

Bird · May 1, 2005

( not to use air to dry any bearing )

I think that recommendation has existed since before my time. However, I've used compressed air a lot to dry bearings, but not to spin them, because you really could get some tremendous RPM that way. And as someone else has said, that sure ain't the way you inspect one for damage. I do that by turning them very slowly by hand and visually inspecting them for any pitting, chipping, etc.