Trailer Bearings

[rando]

Ive just finished replacing the bearings on my trailer(first time for me)
One wheel im pretty happy with, Right hand wheel,spins ok but pulls up after two or three revolutions. I completely filled the hub with grease,,,, Too Much???
Left wheel , full but quite as much!!!

Right hand wheel also had a bit of trouble getting the split pin in, I was sure I seated the bearing cup properly, but now I wonder if I did ,as the nut was 1/4 turn tighter than i wanted.

Can anyone offer me some advise please? as Im towing it to Iluka tomorrow?

[lippa]

http://www.ausfish.com.au/vforum/sho...light=bearings


have a look at this thread, it may help, there are a heap more if you do a search as well.

ya can also youtube it to find videos on bearings

cheers

lippa

[disorderly]

Ive just finished replacing the bearings on my trailer(first time for me)
One wheel im pretty happy with, Right hand wheel,spins ok but pulls up after two or three revolutions. I completely filled the hub with grease,,,, Too Much???
Left wheel , full but quite as much!!!

Right hand wheel also had a bit of trouble getting the split pin in, I was sure I seated the bearing cup properly, but now I wonder if I did ,as the nut was 1/4 turn tighter than i wanted.

Can anyone offer me some advise please? as Im towing it to Iluka tomorrow?

Had exactly the same thing happen doing my bearings today,though I couldn't get the split pin in at all...had to pull the wheel back off and the outer bearing back out and tap the bearing cup in a bit harder with hammer and screwdriver....First try I didn't want to damage it and subsequently had not seated it right in.(was only maybe a mm in it though)

I doubt you have too much to worry about though if you could actually get the split pin in and still spin the wheels...maybe just check it after the trip and see if it has loosened up.



Hope you get a few fish down there .

Scott

[ozbee]

Most wheel bearings fail new from over tightening not lossenes . The second most reason bearings fail new is because of too much grease not to little. My engineering handbook back from my apprentice days always said bearing housings should only be one third filled. Firstly if your wheel will not spin easily like a dozen turns you have actually preloaded the bearings. this means you have tightened the bearings by the nut to a point they have seated plus the small amount between the cone faces (both outer cone and inner cone) yes the wheel will still turn but you will feel a slight drag as it rotates. it is this tolerance where the grease has to lubricate. Unfortunately the further you drive the heat build up expands the distance between the bearings which speeds up failure.

(the two bearings not the two faces)

WHY IS TOO MUCH GREASE WORSE THAN LESS

grease is fundamentally made up of two major components one is oil which is the lubricant and secondly fat which is the carrier


Oil is pretty straight forward

The carrier is designed to hold the oil in contact with the bearing surfaces but most importantly that after a certain amount friction{heat generated} it will melt thus allowing fresh grease to be able to come in contact with the surfaces . also it has the ability to re solidify when it cools, so the cycle can go round and round . When you have excess grease it draws the heat out delaying the grease close to the bearing to melt so unfortunately the rotation of the grease is actually slowed right down between the bearing surfaces . hence less bearing life .

Turn the nuts back another quarter to a third turn would give you the ...005 thousand of a inch clearance to both bearings to enable proper lubrication .

Hope this helps also greases have come forward a hell of a lot with countless additional lubricants many which are fin ate solids designed to fit between those tiny wearing faces to lengthen bearing life .

[rando]

Ozbee
Thanks I had a feeling I had heard you can put too much grease in.
I was operating on the principal, that if it is FULL of grease the water wont get in.
Also. neither wheel had a flat washer between the nut and bearing,this might pose a problem if I add a washer I may not be able to put the split pin in.
This is sounding ugly!!!

[Roughasguts]

I don't know about putting to much grease in. Cause that's how bearing buddies work by removing any air pockets in the hub, therfore no water can get in and destroy your bearing races.

But if you put to much grease in you push out the rear seal, that's where to much grease will fail a hub.

My current bearings are 8 years old on gal hubs with bearing buddies fitted, mind you very low mileage.

On the other hand my Box trailer is 29 years old, hardly any grease in the hub and still original bearings.

[backlash08]

ozbee is on the money - tapered roller bearings should run zero end float and zero preload, definatly do not over grease, too much grease retards cooling, if grease is not on the bearing it is doing nothing to help as the nature of the lubrication is 'dynamic' lubrication and using the oil out of the soap to lube the bearings. bearing buddies do work and work well however use one evil (excessive grease) to over come a bigger evil (water) in the perfect world you wouldnt have excessive grease or water - personal choice in the end
cheers
Craig

[Roughasguts]

ozbee is on the money - tapered roller bearings should run zero end float and zero preload, definatly do not over grease, too much grease retards cooling, if grease is not on the bearing it is doing nothing to help as the nature of the lubrication is 'dynamic' lubrication and using the oil out of the soap to lube the bearings. bearing buddies do work and work well however use one evil (excessive grease) to over come a bigger evil (water) in the perfect world you wouldnt have excessive grease or water - personal choice in the end
cheers
Craig

Hi Craig, mate I still don't know can you over oil ? no you can't! so how can you over grease ? Sure grease doesn't dissipate the heat like oil will, but if it's there it's liubricating isn't it? grease will break down with heat, and turn almost to oil provided it's hasn't been there for years and already dried out.

Sure you have to clean the hubs out and replace with fresh grease, but you also have to do that with finely greased bearings as well,

Grease does dry out.

[disorderly]

Really interesting discussion guys.
Certainly never heard the "too much grease is bad" theory before but keen to hear more...
Wonder if it has come about because of different grades and types of grease....
Is it a problem to use a lower quality general purpose grease in bearings rather than a specified bearing grease?
What is the actual physical difference between a low quality and high quality grease?

Scott

[backlash08]

Guys,
Agree, interesting discussion. There are significant differences in greases, they have different base oil viscosity (like lubricanting oils) and different soaps. basically grease is like a oil in a sponge, the sponge is the soap in a grease, the type of the soap (lithium, clay, calcium etc) will influenece the drop point, the point at which the oil will freely drop away from the soap. Also the soap in the grease holds no more tasks than simply holding the oil in place, soaps have disadvantages such as not displacing heat, retaining water etc.
Now to the questions, grease will not lubricate even if it is in the hub but not in contact with the bearing, generally grease will not drop oil out until arounf 150c, wheel bearings wont run anything like that temp (assuming bearing are in good order and correctly adjusted) so grease that is not in the area close to the bearing will never 'bleed' down to the bearing and lubricate and will only hold the heat in, hence my point why too much grease is bad. In marine and dirty environemnt grease may be the better of two evils (keeping out dirt or water like a seal) but it is far from good to have too much grease apart from sealing purposes.
On the question of good quailty vs lower quailty greases - oils aint oils so they say, quailty is influeneced by the quaility of the base oils and polymers used and the type of soaps that are used, ability to withstand water washout, oxidation and tempurature stability are all very important characteristics of grease and a tribologist could write 10 books on this subject alone. the real trick with grease is using the correct product for the application, a grease that may be excellent for a high load low speed application could fail very quickly in a high speed application like a wheel bearing or electric motor.
The trick for us boaties, use a reputable brand wheel bearing grease something like an NLGI 2, lithium complex soap - I use Castrol APXT and have done for years

In my opioion use new seals and bearings every 12 - 18 months, dont over (or under) grease (bearing and a small palm amount of grease in the hub only), run no preload or endfloat and you'll never have an issue

http://www.castrol.com/castrol/gener...tentId=6008468

[rando]

Clee
Sounds like Ill have to take all that grease out.

Roughasguts...
Yes,when I fitted the front bearing I had grease expressed through the rear seal.
If I reduce the amount of grease and clean up the seal contact faces, I should be allright??????

And now to the question of the washer.
There was none fitted,
Should I fit one
If, when fitted, I cant get the pin in do I then not worry about a washer, or do I wait to leave till I can get an appropriate shim to fit????

Rando

ps
I used Evenrude marine wheel bearing grease.

[backlash08]

Rando,
you should have a washer, just dispalces the load a little better from the bearing onto the nut and stops fretting , but its not an absolute game breaker,
without looking at it, I would take a bit a grease out of the hub, if the seals were new (and im assuming they were) they'll be fine just put the hub on, fit the washer (if you can get one) tighten the nut up tight to make sure that everything is bedded in, back the nut off and adjust the wheel bearing, as far as the grease you used, dont know anything about the brand so i assume it would be OK
cheers - Craig

[Roughasguts]

Rando, yeah it should have a washer between the castle nut and the bearing.
If your having trouble fiting the split pin have you trimed it back to fit, it should be no longer than the last pin that was in. Trimming split pins and banging them tight up agains't the castle nut to get them inside the cap is aceptable practice.

[rando]

Thanks guys
Your info is great, Ive found a few washers that should do , but they are pretty heavy gauge.
The problem with the pin is that the hole is somewhat covered by the nut if i back it off say 1/2 turn from finger tight.
What im going to do, is, get some of the grease out, install the washer, then pinch it up hard with a spanner then back it right off, then tighten it, to a bit back from finger tight , and see if the pin fits.
I'm using the empty trailer to carry all our gear , bikes, kayaks etc etc. And i don't yet have a spare wheel ,so i cant afford to get this wrong with a three hour drive ahead.
Thanks again, the old "Ausfish brains trust", what a great bunch you blokes are.
rando

[rando]

Hi Guys
I got the grinder out and gave these washers a bit of a grind, reduced the
thickness buy about a mm, soooo, even with the thinner washers the pin wont go in.
Can I drive this without a washer. Possably explains why no washers were installed to start with.
rando