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Inland RV Center, In · 04-22-2004, 07:52 PM

Tag axle motorhome owners should be aware that a regular check up is necessary, to insure trouble free operation.

The air bags should be extended to 10 1/2 inches. If they are lower than that, unusual loads could be placed on the tag axle, that can lead to failure.

Additionally, since the tag axle is a variation of the trailer axle, it uses 12 inch "ELECTRIC" brake assemblies, just like the trailer.

Therefore it is wise to check the tag axle brake assembly every 10,000 miles, and repack the bearings, and replace the grease seals. The magnets should last about 20,000 miles and the shoes about 50 to 60,000 miles, and be replaced as necessary.

Some owners are not aware that tag axles are "NOT" equipped with hydraulic brakes.

Andy

swebster · 04-22-2004, 08:49 PM

Ya know...just when I thought I could stop working under the RV and get back to the interior now Andy is coming up with things for me to do!

Andy,
Seriously, thanks for the notice. I've inspected, repaired or replaced most of the running gear on my MH chassis since purchasing it last July, but I haven't given those tags, or their brakes much thought at all - until now.

kerwooddr · 07-13-2004, 09:47 AM

Thanks for the head's up. I was inspired enough to drop the jacks and raise the tag axle wheels in the air. Gave them a good spin by hand and stepped on the brakes. Nothing - key on, key off, engine on and off. The wheels kept spinning. Looking underneath I found two wires to each brake hub, with the starboard wire disconnected. Reconnected, but still no brake action.

So, what safety features are in these electric brakes? For example, if one side is not functioning, will the other continue to function or are both wheels needed to make a complete circuit? Is there a mechanism that balances the braking force from side to side?

Thanks in advance.

Quote:

Originally Posted by Inland RV Center, In

Tag axle motorhome owners should be aware that a regular check up is necessary, to insure trouble free operation.

The air bags should be extended to 10 1/2 inches. If they are lower than that, unusual loads could be placed on the tag axle, that can lead to failure.

Additionally, since the tag axle is a variation of the trailer axle, it uses 12 inch "ELECTRIC" brake assemblies, just like the trailer.
Andy

thenewkid64 · 07-13-2004, 10:18 AM

Quote:

Originally Posted by kerwooddr

So, what safety features are in these electric brakes? For example, if one side is not functioning, will the other continue to function or are both wheels needed to make a complete circuit? Is there a mechanism that balances the braking force from side to side?

David,

There should be an electronic brake controller under the dash. It is what activates the brakes. Looks like a black box with an LED on it. If this does not have power, neither will the brakes. The only real way to test them is with them off the ground, spin the wheel and manually active the brake controller using the slide lever. The controller is inertia based so stepping on the brake pedal while stopped will usually not produce much current to the brake magnets.

If you still do not have brakes I would check the wiring to be assured that you have voltage coming to the brake assemblies by checking the wires with a meter while a helper slider the lever. Lastly this needs to be done with the key on. The brake controller is not on if the key is off.

Inland RV Center, In · 07-13-2004, 10:40 AM

David.

The motorhome brakes are not quite enough to properly stop the motorhome.

Therefore, the electric brakes on the "tag" axle augment the motorhome brakes.

Each side is wired in "parallel."

There could be several reasons your tag axle brakes are not functioning.

I would suggest that you start at the controller to check the entire system.

Andy

pillageTHENburn · 07-19-2004, 08:23 AM

On a similar note... I recently (yesterday) bought a '74 Argosy Motorhome... it has a tag axle and I was wondering if there is a good/easy rule of thumb as to how full to keep the air bags (driving/not driving)? Even a visual idea of what is "right" would be nice. I know that things change with the different weights that you have in the trailer...so I suppose I'm just looking for a ballpark...
Thanks for your help!
-Logan

87MH · 07-19-2004, 08:30 AM

Bag height should be 10 1/2", max weight on tag should be 1500 lbs on each tire.......

Yours may not be the same - there should be a tag located on the axel stating the max allowable weight (mine is located at the midpoint, on the rear horizontal face of the tag axel).

Did you find anything else wrong during the inspection?

Inland RV Center, In · 07-19-2004, 08:46 AM

Logan.

Argosy motorhomes never had a "tag axle."

The correct air bag specification for your motorhome, is 8 3/4 inches.

That is the dimension from the top to the bottom of the air bag.

The 10 1/2 inch spec is for 1982 and up motorhomes.

1981 and down is 8 3/4 inches.

These dimensions are per Airstream and Henschen.

Also, the front air bags, must be at 55 psi, no more, no less.

Andy

swebster · 07-19-2004, 09:41 AM

Andy,
Logan has a unique Argosy. It was extended and tags added (reportedly by Airstream in the early eighties).

Logan,
You may be on your own with this one as you have such a rare bird. Measure the pressure and height of the bags now. I think the measurements from a 325/345 would be "close" but you'll have to experiment. Obviously, you need air in those bags or you will destroy your rear suspension.

74Argosy24MH · 07-19-2004, 09:44 AM

Quote:

Originally Posted by Inland RV Center, In

Logan.

Argosy motorhomes never had a "tag axle."

Andy

This one does.

How much documentation did you get, any that gives a conversion date? If not you should be able to figure from the air bags, they stretch some but won't be able to go 2".

55 psi on the front bags is what GM filled at the factory and what they were aligned with. If you are heavily loaded you will need to have more than 55psi, but you should also get the front realigned as it will affect camber. Never less than 55 psi.

John

pillageTHENburn · 07-19-2004, 11:08 AM

Quote:

Originally Posted by 74Argosy24MH

How much documentation did you get, any that gives a conversion date? If not you should be able to figure from the air bags, they stretch some but won't be able to go 2".

None yet actually. So at this point I am not POSOTIVE that it was officially done by Airstream, I have not seen any PROOF. However the people who I have had take a look at it have said that it looks professionally done, I do not know if this means AS or maybe just a professional fabricator.

The good thing is that I was given the phone number to the original owner (well his son, being that the original owner is now dead). It has been in their family from the beginning and I am told that this guy has "before and after pictures with some from the actual modification process itself". Supposedly this guy is really nice and would love to share the story with me, I am looking forward to that phone call! If he has pictures I am sure he has more, so I'm hoping to get some documentation of some sort. If it ends up being a non-factory job I'll get what I can. Now that I own it (and it is efficiently blocking my view in front of my house) I can take some more picture (better pictures).

I will be sure to keep eveyone posted as to what this turns out to be.

No matter who did I am pretty happy right now. I'm gonna roll up my sleeves and prepare for a lot of work!

-Logan

swebster · 07-19-2004, 11:41 AM

Logan,
If you get those pics...please post them on the forum. I for one am very curious about your new ride and how it was done.

pillageTHENburn · 07-19-2004, 03:18 PM

ME TOO!!!

I will post them for sure!

-Logan

87MH · 08-06-2004, 10:34 AM

Andy:

I need to pose a hypothetical question.....

Let's suppose that a tag axel has been overloaded.....

a combination of overloads.....

too heavy a trailer, too much weight on the tag, imbalanced tires, etc....

What type of damage (other than ruining the rubber torque rods) could be anticipated.....and/or, more specificly, what type of damage have you actually seen.

ravi · 02-27-2013, 12:25 PM

Wanted to get my tag axle bearings repacked over at a Wingfoot. Any advice on seals etc? I have no idea about this but just wanted to do it so everything runs smoothly on the tag. Don't know when this was done last as I've only had mine about a year. Thanks!!!

Ravi

Inland RV Center, In · 02-27-2013, 01:28 PM

Quote:

Originally Posted by ravi

Wanted to get my tag axle bearings repacked over at a Wingfoot. Any advice on seals etc? I have no idea about this but just wanted to do it so everything runs smoothly on the tag. Don't know when this was done last as I've only had mine about a year. Thanks!!!

Ravi

The grease seals used in the tag axles are double lipped with a spring.

They are the same one's that came with the original tag axle.

Do not use the auto parts store cheapies.

There is but one new tag axle available in the US, so don't take any chances, as that new axle, is not cheap.

Andy

wvabeer · 03-18-2013, 09:40 AM

What is the seal number and in my manual it says to use lithium grease, which type of lithium grease?

Inland RV Center, In · 03-18-2013, 12:45 PM

Quote:

Originally Posted by wvabeer

What is the seal number and in my manual it says to use lithium grease, which type of lithium grease?

The tag axles are the same thing as used on the trailers, but with different types of hardware.

Bearings and grease seals are the same.

Andy

ravi · 03-18-2013, 12:59 PM

I went to Wingfoot and they simply squirted the lithium grease in the wheel hub zert. While they were at it, I had them lube the whole chassis. Man, I felt great about that. It seems to ride a lot smoother from that. And I definitely don't have the squeaks that I had before. Tested it out at Big Bend National Park!

Inland RV Center, In · 03-18-2013, 02:32 PM

Quote:

Originally Posted by ravi

I went to Wingfoot and they simply squirted the lithium grease in the wheel hub zert. While they were at it, I had them lube the whole chassis. Man, I felt great about that. It seems to ride a lot smoother from that. And I definitely don't have the squeaks that I had before. Tested it out at Big Bend National Park!

Tag axle condition, should never be assumed.

If their recent mileage is not known, the hub and drums should be removed, the bearings should be repacked and the grease seals should absolutely be replaced.

Then with the drums off the tag axle, what's the condition of the non self adjusting brake adjustment, the shoes and the brake magnets?

The brakes on a tag axle, are exactly the same as the 12 inch brakes on the trailers.

The magnets only last about 20,000 miles and the shoes about 40,000 miles. Without them being examined by eye sight, I would seriously doubt their condition.

There is but one new Airstream tag axle left in the world, and it is very expensive.

Seized bearings can destroy a tag axle very quickly.

Andy