grease seal question

[Troutman3000]

Jack up the axle, pull your bearing buddy or dust cap, pull the cotter pin and remove the castle nut and thrust washer (if so equipped) then pull off the hub. Pull the old seal out and drive in another with the 2x4 method mentioned above.

Be sure to pack your hub full of grease and inspect everything before you put it back together.

That easy huh? How do you know if your hub is busted?

 

[Quackrstackr]

Look for cracks? They should be easy to see if you wipe the grease off with a rag where you think it may be cracked.

The only busted hubs that I have ever seen were catastrophic failures from extreme impact (and one on my current trailer after they strapped it down with too much side load when they put it on the hauler to bring it to the dealership).

I would be more concerned about the bearings needing replacement than a cracked hub.

 

[Troutman3000]

Look for cracks? They should be easy to see if you wipe the grease off with a rag where you think it may be cracked.

The only busted hubs that I have ever seen were catastrophic failures from extreme impact (and one on my current trailer after they strapped it down with too much side load when they put it on the hauler to bring it to the dealership).

I would be more concerned about the bearings needing replacement than a cracked hub.

How do you know if the bearings need replacement. I want to do it all at once if I can.

 

[russ010]

you pretty much have to take them out to know for sure to see if the bearings are bad...

look for pits (literally small pits) on the bearings. If you look through the thread of my Xpress, you can see the pictures I had of my bearings and the replacement process I did -- edit* yep, page 2 is where I have the bearings out - and they literally fell out when I got them off the spindle. If you look at each of the bearings, you'll see how they are all scratched up and pitted.

 

[WhiteMoose]

This thread also has a picture of bad bearings.
https://www.tinboats.net/forum/viewtopic.php?f=3&t=10092&start=10

 

[Troutman3000]

Thanks Guys....Seems easy enough

 

[longjohn119]

A buddy of mine who is a certified mechanic for fork lifts of all sizes told me you need to install the back seals **backwards** when using Bearing Buddies. Those seals are designed to keep water out NOT to keep the grease in so when you install the seals normally the internal pressure caused by the Bearing Buddies will blow out the seal. If you install the seal backwards then the internal pressure caused by the Bearing Buddies will actually make them seal better. To install them backwards I use a galvanized or black iron pipe coupling that the outer metal edge of the seal will just slip over, I think it was a 1 1/2" but I'm not sure because it's been awhile (And haven't gotten that far on my new boat and trailer) They use a similar aftermarket "autogrease" setup on some fork trucks and that's how they have to do it.

Also check the spindle where the seal is supposed to seat and inspect it for damage.

Also repack the bearing and put as much grease as you can get in by hand before you install and use the Bearing Buddy, otherwise the only way to get the air pocket out is to blow the back seal. Another trick is to pack it by hand, install the Bearing Buddy and drive the trailer around a bit to help spread the grease and get the air out, then add your grease to the Bearing Buddy as directed

 

[Quackrstackr]

I'm sorry.. but your buddy is dead wrong. The purpose of the grease seal is to keep the grease inside your hub and to minimize water intrusion. Your seals will most likely withstand less pressure, not more, if installed backwards.

(I work in engineering for an automotive sealing company)

If you still don't believe me, go out and pump your bb's full of grease and see if they don't leak. Seals leak because people just keep pumping grease into them and overfill/overpressurize them. Once installed, if it ain't leakin'... there is no reason to keep adding grease (unless you just want to blow your seals).

High pressure inside your hub from overfill not only causes blown seals, it causes the seals to wear more rapidly, which will also cause them to eventually leak. Most grease seals can only stand about 2.5-3 psi before you will start seeing problems. If you have a high quality seal, you can actually jack the entire thing out of the hub from the internal pressure before it starts leaking at the bead.

 

[KMixson]

There is a spring on the inside of the seal. If you install it backward the spring will be out in the elements and will not last long at all. If you bend the rubber part of the seal outward you will see the spring. It keeps pressure on the spindle.

 

[WhiteMoose]

Finally got around to replacing the leaky seal and was sure to keep the new one flush with the hub. After a couple short trips, the grease appears to be staying where it should. Thanks guys.