EZ lube spindle and bearing repack question

You dont even want to know this much about a seal. Interesting stuff and notice what it's says about the new seal riding in the old path and microasperities.

rjxj wrote:
The end of the dust cover is WIDE open when the rubber plug is removed. There is zero pressure in the cavity. The grease just keeps flowing out the hole around the grease gun fitting. If the seal is bad and bad means that the spring loaded lips have lost contact with the axle surface it could push grease past it. Just as it easily flows toward the dust cap hole it could easily flow past the seal if worn. The grease doesn't care which path it takes if nothing is in it's way. So if the lips are not in full contact it could be easier to go past the seal rather than move the weight of that glob of grease to the dust cap hole. Ez lube lets you freshen the grease between inspections and inspections automatically include replace the seal. Truck shop talk...."When you pull a wheel REPLACE the seal".

Precisely.

mike-s wrote:
So, you don't have any factual data to back your claim. Just as I suspected.

You're funny.

"Factual data" as you call it does not exist. What do you want from me? A video? A Process Specification signed by one of my Professional Engineer cohorts? Yeah right. You still wont believe it.

YOU build the "factual data" yourself by physically trying a procedure that a cave man could follow.

The end of the dust cover is WIDE open when the rubber plug is removed. There is zero pressure in the cavity. The grease just keeps flowing out the hole around the grease gun fitting. If the seal is bad and bad means that the spring loaded lips have lost contact with the axle surface it could push grease past it. Just as it easily flows toward the dust cap hole it could easily flow past the seal if worn. The grease doesn't care which path it takes if nothing is in it's way. So if the lips are not in full contact it could be easier to go past the seal rather than move the weight of that glob of grease to the dust cap hole. Ez lube lets you freshen the grease between inspections and inspections automatically include replace the seal. Truck shop talk...."When you pull a wheel REPLACE the seal".

RinconVTR wrote:

mike-s wrote:

RinconVTR wrote:
It takes more effort and pressure to push grease thru a zerk fitting than it does thru the EZlube system!!!!

So what? Either can exceed the pressure the seals can handle.

I couldn't find any good reference, but you claim to know. How much pressure does it take to push grease through the EZ-Lube system, under what conditions, and what's the source of your information?

Prove it to yourself

So, you don't have any factual data to back your claim. Just as I suspected.

mike-s wrote:

RinconVTR wrote:
It takes more effort and pressure to push grease thru a zerk fitting than it does thru the EZlube system!!!!

So what? Either can exceed the pressure the seals can handle.

I couldn't find any good reference, but you claim to know. How much pressure does it take to push grease through the EZ-Lube system, under what conditions, and what's the source of your information?

Prove it to yourself, in a very crude by feel method only.

- Operate the grease gun handle normally, nothing attached
- Attach an loose grease zerk to the gun, pump again
- Now pump the EZlube

Result...all the same.

Finally, something else I have tested and also made a mistake with on trailers (utility and boat) that have bearing buddies (spring loaded, holds a light constant pressure when loaded correctly) is I overfilled them. A couple times on purpose, but before that by mistake.

I mention this because in doing so, you will find for yourself how much grease gun handle force is required to push out an axle seal. Its uncomfortably high and you will quickly learn any more pressure than pumping thru a bare zerk is too much.

The EZlube flow thru hole is significantly larger than zerk fittings and there is no where for pressure to build up with the rubber cap removed. It is 100% impossible to blow out a good working seal via EZlube zerk.

RinconVTR wrote:
It takes more effort and pressure to push grease thru a zerk fitting than it does thru the EZlube system!!!!

So what? Either can exceed the pressure the seals can handle. The seals aren't made to withstand much pressure, they're there to keep unpressurized grease in place. The common "10-36" single lip seal, which Dexter specs for the 5.2/6k EZ-Lube axles, is only rated to 10 PSI (based on SKF specs for the seal they cross reference).

I couldn't find any good reference, but you claim to know. How much pressure does it take to push grease through the EZ-Lube system, under what conditions, and what's the source of your information?

plasticmaster wrote:
My TT axles have the EZ lube spindles with the grease fitting on the end. It's time for me to repack the bearings. Is it safe to hand pump new grease through the fitting while slowly turning the wheel, or do I need to remove, clean, and repack the bearings by hand? If so, what's the purpose of the grease fitting on the spindle? I bought my camper brand new a little over a year ago. Thanks.

Fact is, the EZlube zerks are not used by any OEM and has no relation to leaky seals.

If a seal leaks while adding grease thru the Zerk the seal was likely already leaking and is bad anyway thus needs to be replaced. It takes more effort and pressure to push grease thru a zerk fitting than it does thru the EZlube system!!!!

Good, working seals can retain significant pressure. The rubber cap for example, will relieve pressure in the closed system long before the seal ever will.

Now, in regards to using the EZlube system for maintenance, it is very handy to "refresh" the grease in between major overhauls which are supposed to happen every 12,000 miles. (Never-mind the 1 year addition LCI also adds, that's just foolish)

Westcoasting wrote:
Every trailer i have owned i originally checked/repacked the wheel bearings. Never needed more grease after that but i do check things out every four or five years or so. Do people repack the vehicle bearings as often?

I would never put a new or used trailer in service before completely servicing the brakes and bearings. These things are built on the cheap and I need to know what I have. I have had the cheap import bearings fail after just one long summer, and they would have not gone another 2000 miles.

I have repacked the bearings on my 1979 Chevy van three times and the bearings are fine, but they aren't the cheap junk used on trailers.

Every trailer i have owned i originally checked/repacked the wheel bearings. Never needed more grease after that but i do check things out every four or five years or so. Do people repack the vehicle bearings as often?