Posted 2005-07-12 10:56 AM (#27959) Subject: Trailer axle grease
Member
Posts: 30 Location: Summerville, SC
Bought a used 2003 4H GN in the beginning of this year that had Zerk fittings in the center of the axle hubs for greasing the wheel bearings (like a boat). What an awesome feature. I finally got around to adding grease this weekend. I pumped grease into the hub zerk fitting untill it just started to come out the front of the bearing as specified in my owners manual. It took 1/2 of a 14oz tube of grease for each wheel . Obviously this must have been the first time it has been done in a very very long time. My question is how often should I add grease? Obviously it is based on how far the trailer is towed but is there a magic numer like every 3,000 miles or something?
Posted 2005-07-12 12:19 PM (#27962 - in reply to #27959) Subject: RE: Trailer axle grease
Expert
Posts: 2958 Location: North Carolina
Careful ... with that grease gun ... The grease has to go somewhere. I believe ... If it blows out the back seal, that grease is going into the brake drum area.
Kay ... would you elaborate on this issue.. I remember you commenting on this before.
Posted 2005-07-12 1:04 PM (#27963 - in reply to #27962) Subject: RE: Trailer axle grease
Expert
Posts: 2828 Location: Southern New Mexico
I asked about this last time. I was told that the grease comes out the front around the grease fitting (it did) and with a manuel grease gun it will be hard to blow out the seals. It was the power guns that were blowing seals. my trailer also used half a tube for each tire. I kept putting in new grease until the grease comming out was clean.
Posted 2005-07-12 3:25 PM (#27971 - in reply to #27959) Subject: RE: Trailer axle grease
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Posts: 1416 Location: sc
Originally written by FordLvr on 2005-07-12 11:56 AM
Bought a used 2003 4H GN in the beginning of this year that had Zerk fittings in the center of the axle hubs for greasing the wheel bearings (like a boat). What an awesome feature. I finally got around to adding grease this weekend. I pumped grease into the hub zerk fitting untill it just started to come out the front of the bearing as specified in my owners manual. It took 1/2 of a 14oz tube of grease for each wheel . Obviously this must have been the first time it has been done in a very very long time. My question is how often should I add grease? Obviously it is based on how far the trailer is towed but is there a magic numer like every 3,000 miles or something?
technically you should not "have to add grease". if the grease is escaping past the seals during use of the trailer, they need serviced. i would try to locate an owners manual for the axle type you have, that way youll know the service intervals. dexter and alko are both on the web.
Posted 2005-07-12 3:35 PM (#27972 - in reply to #27963) Subject: RE: Trailer axle grease
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Posts: 2689
Originally written by Terri on 2005-07-12 1:04 PM
I asked about this last time. I was told that the grease comes out the front around the grease fitting (it did) and with a manuel grease gun it will be hard to blow out the seals. It was the power guns that were blowing seals. my trailer also used half a tube for each tire. I kept putting in new grease until the grease comming out was clean.
It is GENERALLY true that most of us can't put out enough volume at enough pressure to blow out rear seals. You would need an incredibly FAST and STRONG grip and even then the gun wouldn't recover for the next stroke.
There is a lot of fun stuff to get lost in on greases, don't let terms like "drop point" scare you, or the claim that certain greases are incompatible with each other. First time take the whole hub apart and WASH the old grease out, then stick with one grease type - another advantage of DIY, no grease type mixing.
Note to buyers of used trailers: Take your grease gun with you when you go trailer shopping, leave it in the trunk initially. Ask if the trailer you're interested in has been well maintained (like they're going to TELL you if it wasn't). Produce your grease gun and try just ONE hub, if it takes more than three strokes of a small gun - you were lied to. WALK (-:
PS I have a preference for moly greases and oils.
This is a bit controversial, but nothing worth getting rabid about - like the synthetic vs mineral oil issue (-:
Posted 2005-07-12 5:19 PM (#27975 - in reply to #27971) Subject: RE: Trailer axle grease
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Posts: 2689
Originally written by chadsalt on 2005-07-12 3:25 PM
Originally written by FordLvr on 2005-07-12 11:56 AM
Bought a used 2003 4H GN in the beginning of this year that had Zerk fittings in the center of the axle hubs for greasing the wheel bearings (like a boat). What an awesome feature. I finally got around to adding grease this weekend. I pumped grease into the hub zerk fitting untill it just started to come out the front of the bearing as specified in my owners manual. It took 1/2 of a 14oz tube of grease for each wheel . Obviously this must have been the first time it has been done in a very very long time. My question is how often should I add grease? Obviously it is based on how far the trailer is towed but is there a magic numer like every 3,000 miles or something?
technically you should not "have to add grease". if the grease is escaping past the seals during use of the trailer, they need serviced. i would try to locate an owners manual for the axle type you have, that way youll know the service intervals. dexter and alko are both on the web.
Yes, if, as you say, it is escaping past the rear seal.
THAT is one of the things to check for when you take the wheel off - and again if you chose to test it with a couple of grease gun strokes.
A blown out rear seal will be very obvious once the hub is off, they're cheap, easily replaced and worth having on hand (worth carrying around?).
Also, I think the probability of completely FILLING a new or newly serviced hub with grease is low. Air spaces will probably be there and create the illusion that grease is being "consumed" when you next add grease.
I don't know what the schedule is, though I think it is 12,000 miles. I tend to do it in the early Spring and again before any scheduled "long" trip (over 1,000 miles) as a precaution. Just be careful when removing the rubber plug, don't pry it out with a small screwdriver, it is likely to tear and eventually let in water.
Posted 2005-07-13 9:28 PM (#28034 - in reply to #27959) Subject: RE: Trailer axle grease
Member
Posts: 23
Well, someone must be using those fittings, otherwise they wouldn't be putting them there. But me, I'm not one of them. I've blown out too many seals with manual grease guns to trust anything but direct lubing ever again. (And yes, I do it per the axle mfr's recommendations.) Even the shop that does the "heavy-lifting"-type service on my trailers NEVER uses the fittings--they ALWAYS pull the hubs. No exceptions, they say. They tell me they've seen too many blown seals, too many sets of grease-coated brakes, even cases of "grease churn & burn" because hubs were packed so tight with grease by a customer that the stuff began to whip up, overheat, and finally break down and take the bearings with it. An advantage of pulling the hubs is that you get to do bearing/brake inspections and re-set the hub nut (you may be shocked at what you find in there that you never suspected!). KS.
Posted 2005-07-14 11:52 AM (#28053 - in reply to #27959) Subject: RE: Trailer axle grease
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Posts: 2689
In the interest of avoiding such absolutes as "always", "never", "cannot", etc.;
I'd like to say that it is ALMOST impossible to blow grease out of a rear seal that is in good/fair condition with a manual grease gun on E-Z lube type fittings. IF your seals are in bad shape - REALLY BAD shape - then some grease could get past them, but it is probably getting past them anyway and you SHOULD be checking for signs of that and not just pumping grease in until it flows into your left boot. There is nothing but old grease holding the grease in at the outer bearing, there should be little/no pressure in the new grease to find it's way out through the rear seal. The old grease that you see coming at you is giving way long before the rear seal is yielding;
IF the rear seal is still serviceable - - and if it isn't... ???
IF the old grease hasn't congealed into something resembling hard wax
IF - - Gee, the need to over qualify one's statements here is getting to be very Kerry'esq
As to shops and their "position" on this - of course they want to disuade customers from DIY.
I really DO NOT believe that grease can be packed too tight in a hub, even in those spring loaded bearing buddy automatic devices that maintain a positive pressure in the hub.
Trailer axle grease
. Obviously this must have been the first time it has been done in a very very long time. My question is how often should I add grease? Obviously it is based on how far the trailer is towed but is there a magic numer like every 3,000 miles or something? 
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