Hub Seals

[chris_s]

Well the weather gods have finally smiled upon us and i didn't have to work today (sat) for a change, so it was arranged that myself and a couple of mates would head offshore.
All was planned and ready and we were on our way at approx 2am, UNTIL, 15 min into the trip i hear a strange noise from the trailer. "Bearings" i say to the others. And yes it was the bearings. Not much i can do at 2am in the morning and seeing that we were luckily not far from home it's decided to head back for a bit more shut eye and sort it at day break seeing that we all still wanted to go.
That short 15 min trip home took it's toll on the disc hub not to mention not winning any friends with the neighbours as it squealed it's way back up the street to home.
So anyhow i pulled it apart and replaced hub and bearings, but to my dismay i find that the hub seals on the BOAT TRAILER are only dust seals and no matter how much you regrease or use bearing buddies or the like, fatal damage is imminent. All four hubs are the same.
I know i know it's very hard to keep them totally water tight but it's even harder keeping them dry with only dust seals. So tomorrows job is to replace all bearings and seals, and to buy a spare hub to carry with the trailer.
It just makes me wonder how many others out there have the same or are unaware because they are out of sight, out of mind.
But by replacing the dust seal with water seals preservation of the bearings will be alot better.

[FNQCairns]

Do you mean it has automotive type seals? I have gone back to these due to the marine seals letting even water from the hose and even rain water inside. They give me good compression onto the axle and a solid fit on the seals outer into the hub.
I use a lot of grease, pack the seal real well inside and out, works for me at least better than the marine ones do. If the rain stays away will be doing my 6 monthly bearing check tomorrow (actually been 8 months), so will see what around 50 deep dunkings with up to a 25km trip each way has done to the bearings.

cheers fnq

[Poseidon]

I am no seal expert, but found the seals that came with my original bearings to be a pain. They sat in the hub with a spring arrangement to put pressure onto the axle. I didn't like them as they were difficult to remove from the hub to get the rear bearing out.
Have since replaced with the seals I have been use to in the past which has the stainless steel cup that you tap into the hub and the rubber seal sits on the axle and makes a seal inside the cup. I find the stainless cup easy to remove to get to the rear bearing.

I remove hubs,clean and repack with grease every 4 months or so and carry a spare hub and bearings for the just in case times. Grease is cheap and rainy days up here give you plenty of time for trailer maintenance. In both cases there was always a tiny bit of water evident in the grease however would imagine that it is near impossible to stop water entirely given the dunking that trailers receive.

Is the one with the spring arrangement called a 'marine seal' and the other one called an automotive seal??

Regards Cameron.

[dogsbody]

http://titanbrakes.com.au/index.php?page=accessories&acc_type_var=10&site=v2

Try these pressurized bearing protectors.


Dave.

[littlejim]

Like FNQ, I found once I started packing the SEALS with grease, as well as the bearings, I got a lot more life out of the bearings. (I'm just using the standard marine bearing kit where the ribbed seal goes into a metal cup on the hub.)

On mine, the bearings used to go at 6 mnths, always the big inner one near the seal. Now they last for years.

[FNQCairns]

Just finished checking the bearings they are in perfect health so the dust seals work very very well (better than any marine seals I have used) the trailer has done approx 4k on these bearing + the dunkings above, they will last 100k at this rate I could have been looking at car bearings with the same number of km up, there was 0 wear also, used waterproof grease.

The procedure is what makes all the difference it seems.

cheers fnq

[black runner]

There are seals and there are seals. Even in the marine style there are cheapies and good quality ones. My last set (bearings and seals) was Timken, and the difference in seal quality was significant.

It is really important to clean everything off the seal mounting surfaces. With the marine type seal you need to ensure that the stub on which the seal mounts is of a diameter that will expand the seal, so that the seal lip actually makes sufficient contact with internal surface of the stainless cup in the hub. If not the only thing keeping the water out is the outer flat lip. I also seat my marine seal onto the stub with a non hardening sealing compound. I also use the same compound on the dust cap. Never get water in. Lubricate all seal running surfaces prior to assy.

When I bought my previous boat the axle diameter where the seal mounted was to small and the seals never worked properly.

If using the automotive type try to press the seal into the stub. If you need to tap it in ensure you pack grease around the seal spring as this will keep it from popping off from the shock.

Cheers - Fred

[Dignity]

This topic pops up as regular as clockwork. Maybe we need a thread as a sticky with some pics or even video on the subject. I know I would appreciate it as I am finding it hard to picture some of the descriptions. Only ever used the marine style seals which is basically a large rubber seal that sit on the axle and presses against a SS hub insert. Never mucked around with cars, so what is an automotive type seal and where does the spring all fit - I am interested as I run a tandem axle and I've seen the way the leading tyres and hubs work on tight turns and it concerns me as to the impact this has on the seals and bearings.

[FrankFWM]

http://titanbrakes.com.au/index.php?page=accessories&acc_type_var=10&site=v2

Try these pressurized bearing protectors.


Dave.

I have got these on my Jetski trailer and am trialing them - They have been on for about 5 months nd so far - pretty good....

On my dual axle boat trailer, I have durahubs which have been on there for about 5 years - never had an issue with them either :)

[John_R]

I have durahubs on my boat trailer. Been on for over 2 years with cheapo chinese bearings. Been to 1770 from Brissie a couple of times, up to Rainbow beach several times, Waddy Point once so far and Mooloolaba a dozen times . Last trip I noted they got a little warmer than normal so it's time to go for new bearings.

Can't seem to find the back seals on the shelf anywhere so will contact durahub to get some new ones so I can change the bearings. The seals are on a spring steel carrier that you have to wreck to get back out of the hub.

Provided you can get a good seal at the rear, I reckon these are awesome. Never had a spoiled fishing trip due to bearings.

[FrankFWM]

You can get the seals from Durahub directly - order them over the phone and pay via credit card - I have done this and they deliver overnight...

Don't forget you will need the loctite from them also...

[FNQCairns]

This topic pops up as regular as clockwork. Maybe we need a thread as a sticky with some pics or even video on the subject. I know I would appreciate it as I am finding it hard to picture some of the descriptions. Only ever used the marine style seals which is basically a large rubber seal that sit on the axle and presses against a SS hub insert. Never mucked around with cars, so what is an automotive type seal and where does the spring all fit - I am interested as I run a tandem axle and I've seen the way the leading tyres and hubs work on tight turns and it concerns me as to the impact this has on the seals and bearings.


Hi Dignity, the dust seal is a one piece seal of more or less the same design used on virtually all motor crankshafts and any other mechanical area where the inner surface needs to seal a spinning shaft.

To fit to a boat trailer trailer hub the Marine seals SS insert is removed, the outer edge of the dust seal compresses into the hub proper and the inner surface compresses onto the axle so it is simply a 1 piece seal with a waterproof compressed fit on all surfaces that may allow ingress of water. The marine ones seem to me to work on the principle that one surface must remain a contact only (touch) fit.

cheers fnq

[station-rat]

Automotive type seals are designed to keep the grease or oil in, not the water out. In the marine seals the sealing area is also much larger and runs on a SS insert

[Dignity]

Station rat - I find that the SS seals don't seem to work on my trailer - I have a tandem and I notice that when reversing or taking sharp corners the front and rear wheels are often at opposite angles to each other. From this I would suppose that the seal itself would end up being pushed away from the SS mating surface, not much but enough to create a water leak. I don't understand the dynamics of how the 2 wheels work so my assumption is probably totally wrong. I will give the automotive ones a go as I have aset of them and will put them on just one wheel and see what the difference is.