Tag Axle

[farmerl]

We bought a Coachmen Royal and need to find out about the tag axle. According to the owner's manual it could be air. We don't know? It appears to not be carrying any weight. Help!

[Nick-B]

Hi farmerl and

First we are going to need some additional information.

What year and chassis make is your motorhome?

[ga traveler]

Originally Posted by farmerl

We bought a Coachmen Royal and need to find out about the tag axle. According to the owner's manual it could be air. We don't know? It appears to not be carrying any weight. Help!

Some tags are fixed. You raise the main axel to add or subtract weight to the tag.

[Gary RVRoamer]

And how did you conclude it is not carrying any weight? Are the wheels not touching the ground?

The tag on a gas chassis motorhome is usually fixed in position and the weight it carries depends on the relative air pressure sin the drive axle tires vs the tag axle tires. Less air in the drive tires lowers the rear onto the tag, forcing it to carry more weight. More air pressure in the tag causes it to lift a bit and carry more weight.

[farmerl]

Originally Posted by Nick-B

Hi farmerl and

First we are going to need some additional information.

What year and chassis make is your motorhome?

I am sorry, I just sent a thanks to you with more info. I will figure all this out soon. It is a Ford F450 or 550 - 1994. Has disc brakes on the steer and the drive, but the tag has drum brakes - if that helps - I don't know much!!!

[farmerl]

Originally Posted by Gary RVRoamer

And how did you conclude it is not carrying any weight? Are the wheels not touching the ground?

The tag on a gas chassis motorhome is usually fixed in position and the weight it carries depends on the relative air pressure sin the drive axle tires vs the tag axle tires. Less air in the drive tires lowers the rear onto the tag, forcing it to carry more weight. More air pressure in the tag causes it to lift a bit and carry more weight.

Thank you for responding!!! My husband parked on a tarp and was able to pull the tarp out from under it. It was hard, but still he was able to get it out. The tires aren't bagged at all on the tag. The drive axle tires are very bagged. The air pressure response makes sense, thank you!

[farmerl]

Originally Posted by ga traveler

Some tags are fixed. You raise the main axel to add or subtract weight to the tag.

Thank you for responding!!! How in the world do you do that?

[Nick-B]

Originally Posted by farmerl

I am sorry, I just sent a thanks to you with more info. I will figure all this out soon. It is a Ford F450 or 550 - 1994. Has disc brakes on the steer and the drive, but the tag has drum brakes - if that helps - I don't know much!!!

Its OK, we will work with you on this but your information is still kind fuzzy - at least for me. Your profile says that the motorhome is 39' in length but that would not be correct if you have an F450 chassis. The F550 is not even a motorhome chassis but a medium-duty commercial truck.

I'm going to take a stab in the dark here and guess that you actually have an F53 "Class A" chassis with the 460 gas engine.

Does your motorhome look like this one?



If so, then it is similar to mine and there is no adjustment for the tag axle. However, IF the driven axle has air adjustment (as you mention the drive axle is bagged) then there is too much air in it and some should be let out. I do not have any air bags on my chassis so unfortunately, I cannot advise how that would be done on your coach.

Let us know if the picture looks like your motorhome (which would make it an F53 chassis) and maybe someone has more specific info on the air adjustment.

[farmerl]

Originally Posted by Nick-B

Its OK, we will work with you on this but your information is still kind fuzzy - at least for me. Your profile says that the motorhome is 39' in length but that would not be correct if you have an F450 chassis. The F550 is not even a motorhome chassis but a medium-duty commercial truck.

I'm going to take a stab in the dark here and guess that you actually have an F53 "Class A" chassis with the 460 gas engine.

Does your motorhome look like this one?



If so, then it is similar to mine and there is no adjustment for the tag axle. However, IF the driven axle has air adjustment (as you mention the drive axle is bagged) then there is too much air in it and some should be let out. I do not have any air bags on my chassis so unfortunately, I cannot advise how that would be done on your coach.

Let us know if the picture looks like your motorhome (which would make it an F53 chassis) and maybe someone has more specific info on the air adjustment.

Yes! That is our motorhome!!! My husband said that he can't find any airbags either, but when he said the tires on the drive axle were bagged, he meant that the tires had a lot of weight on them. The tag axle isn't bagged. However, we do have an air horn (we think, maybe it is electric, but it looks like an air horn) and he can't find a compressor to figure out how or why we have the air horn. Thank you again for all of your help!

[Gary RVRoamer]

Your "air horn" is electric, since there is no air supply in your chassis, which is indeed an F53 Ford. The F53 is a derivative of the F550, but is not identical to it and you should always specify F53 when looking for chassis parts. A tag axle is not standard or even optional on the F53 - the coach builder added it when he chose to build a larger, heavier motorhome than the F53 chassis was originally designed to carry. The F53 doesn't come from Ford with air bags over the leaf springs either, but sometimes the coach builder adds those too.

First we need to establish how much air pressure is currently in each tire, tag and drive axle. It sounds as though the tag may have little or none, since the drive axle appears to be carrying the entire load. You should also have a rating plate somewhere that gives the axle capacity (GAWR) of each axle - we really need to know that too. There may be a sticker on the sidewall next to the driver seat. It will also give the max total weight (GVWR), another important number.

See if you can get this date and report it back here.

Typically in a rig like yours, the tag would carry about 3000-3500 lbs of the total weight.

[ga traveler]

Originally Posted by farmerl

Thank you for responding!!! How in the world do you do that?

Your airbags should have a height sensing valve. It adds or subtracts air to the bags. You will have to get with your motorhome manuf. to find out how to adjust the valve. Every manuf. is different. only adjust for your manuf. specs.

[farmerl]

Originally Posted by Gary RVRoamer

Your "air horn" is electric, since there is no air supply in your chassis, which is indeed an F53 Ford. The F53 is a derivative of the F550, but is not identical to it and you should always specify F53 when looking for chassis parts. A tag axle is not standard or even optional on the F53 - the coach builder added it when he chose to build a larger, heavier motorhome than the F53 chassis was originally designed to carry. The F53 doesn't come from Ford with air bags over the leaf springs either, but sometimes the coach builder adds those too.

First we need to establish how much air pressure is currently in each tire, tag and drive axle. It sounds as though the tag may have little or none, since the drive axle appears to be carrying the entire load. You should also have a rating plate somewhere that gives the axle capacity (GAWR) of each axle - we really need to know that too. There may be a sticker on the sidewall next to the driver seat. It will also give the max total weight (GVWR), another important number.

See if you can get this date and report it back here.

Typically in a rig like yours, the tag would carry about 3000-3500 lbs of the total weight.

Thank you so much for all of your sharing of your knowledge. Can you tell this is our first motorhome?!? My husband just went out and checked for the GAWR. The label was under the steering wheel and it said the front axle has 6,000 lb and the rear axle is 11,000 lb. However, if there was something about the tag axle - it is gone. My husband thought he remembered seeing a tag with info on it beside the driver door on the paneling, but my 2 year old grandson was helping us gut it and that was his area. It is gone if it was there. Anyway, Ronnie (husband) went out and looked under the tag axle and he thinks that the two large rubber bushings have turned loose from the steel plates. He thinks that is it! Again, thank you for your help!

[ga traveler]

Originally Posted by farmerl

Thank you so much for all of your sharing of your knowledge. Can you tell this is our first motorhome?!? My husband just went out and checked for the GAWR. The label was under the steering wheel and it said the front axle has 6,000 lb and the rear axle is 11,000 lb. However, if there was something about the tag axle - it is gone. My husband thought he remembered seeing a tag with info on it beside the driver door on the paneling, but my 2 year old grandson was helping us gut it and that was his area. It is gone if it was there. Anyway, Ronnie (husband) went out and looked under the tag axle and he thinks that the two large rubber bushings have turned loose from the steel plates. He thinks that is it! Again, thank you for your help!

It sounds like you have a Mor/Ryde suspension system on your tag. Mor/Ryde vulcanizes rubber pads to steel plates. They have had problems in the past with the rubber seperating from the plates. You MUST do something about this. Your axel is overloaded at this point. Contact Mor/Ryde at 219-293-1581 or 219-294-4936

[Nick-B]

Hi farmerl,

ga traveller has it right. Those are called "rubber shear springs" and if they have separated, as it sounds like, then definitely replace them as soon as you can.