Leaking Rear Seals

JimS123

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I have 3 boat trailers. Two singles and a tandem. Fresh water only. The singles had the dust caps replaced with Bearing Buddies when new before they even hit the water. When the tandem was 10 years old the bearings were repacked, new rear seals put in and BB installed. All 8 wheels have a few squirts of grease put in each fall, just till the springs move slightly.

The tandem only goes 3 miles to the ramp each time. Three of the 4 rear seals leak grease. The other 2 trailers travel a 500 mile round trip once each year and they don't leak at all.

First question - why the difference?

Secondly, if they leak, do they need to be replaced? I replaced one of the leaking ones and it still leaks. The seals are original equipment from the dealer that sold the trailer. Obviously, they aren't worn since they are practically new!

When you say "blow a rear seal" does that mean its bad, or just that its leaking?
 

NYBo

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Re: Leaking Rear Seals

i think you may be overloading the tandem. How many miles total is it used per year?
 

bruceb58

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Re: Leaking Rear Seals

Are you sure you have the correct seal size? There are some oddball axles out there that take a slightly different size inner diameter seal. Also, If there is any pitting on the surface of the axle that the seal rides on, it is going to leak.
 

JimS123

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Re: Leaking Rear Seals

They are definately the correct seals. The shafts are smooth with no corrosion.

Total mileage is probably 50 miles per year. I don't think I over pump them - only enough to make the plate just start to move.
 

109jb

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Re: Leaking Rear Seals

You say that new seals were installed, but you didn't say what the condition of the seal suface on the axle was. If it had any rust or pits it will ruin the seals in short order.

Edit: You must have hit the submit key a few seconds before me.
 

109jb

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Re: Leaking Rear Seals

BTW, when you hear someone "blew a rear seal" they are probably talking about the rear main bearing seal on an engine, not a trailer axle. A blown rear seal on an engine is where the seal fails and ALL of the oil from the engine gets pumped out on the ground.
 

NYBo

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Re: Leaking Rear Seals

They are definately the correct seals. The shafts are smooth with no corrosion.

Total mileage is probably 50 miles per year. I don't think I over pump them - only enough to make the plate just start to move.
You're adding extra grease every 50 miles. That's overkill.
 

109jb

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Re: Leaking Rear Seals

Are the seals single or double lip seals??
 

JimS123

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Re: Leaking Rear Seals

Its been awhile since I redid them, so I can't remember. I do remember that they has a small SS spring around the rubber seal, so wouldn't that be a double lip?

Overkill? Well, each fall when I do the winterizing I find that there is NOT excess pressure on the BB. If I give it one squirt and the hub moves, that's all i give it.

Just as a confirmation of my original post, three of them are leaking and 1 looks OK.
 

bruceb58

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Re: Leaking Rear Seals

What brand trailer is this? Reason I ask is that EZ Loader trailers use different size seals.

Also, single lip seals will still have a spring. If you are indeed using single lip seals, that may be a problem.
 

Bob's Garage

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Re: Leaking Rear Seals

In reference to the "blown the rear seal" it can also mean a problem on the trailer . Just depends on what is being talked about. If it is the trailer, then yes, it means the rear seals on the hub are leaking, or that there has be a major failure of the seal.

I would agree that you are over filling the BB's which is why the seals are leaking, which is why you have to add grease, which causes the seals to leak, which.......

Replace the rear seals with a double lip seal, verify the surfaces are good, repack the bearings, fill the BB's, and then you should be good to go.

I once read a post from someone that stated there should be no reason to have to refill the bearings unless you have a problem. This makes sense to me as the grease does not get used up, nor does it compact. It's either there or not, and if not there is a reason and you have to find it.

Bob
 
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