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Weight On Tag Axle

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I have had my 42' Country Coach with air bag supension weighed. It shows that I am overweight on the rear dual axle by about 3000 lbs but have only about 5000 lbs of weight on my tags. How do I get more weight on the tags?

Who told you that you are over weight? I also have a CC Magna with tag with a 8 bag system. My tag is rated for 12,000 lbs and so should yours. Have you had it weighed by a proffesional shop or person so you can get the info you need? I just had a complete chassis tune and that was part of the inspection. I loaded down when we travel (wife has ton's of stuff ... Rz

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Balancing the weight per axle on a tag axle coach is a little more complex than it might first appear.

Some tags are adjustable (i.e. have a separate control for their air bags). Others use a proportioning valve to air the tag and drive axle as a "unit". If it has a separate adjustment, clearly it is easier to adjust.

Also, adding weight to the tag/removing weight from the drive axle shifts weight TO the front axle. So you will need to verify that your front axle is enough underloaded to allow more weight to be added to it.

So, please post each axle's actual weights (individual wheel positions even better) as well as each axle's GAWR.

Then we can see what might be done.

Brett

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Balancing the weight per axle on a tag axle coach is a little more complex than it might first appear.

Some tags are adjustable (i.e. have a separate control for their air bags). Others use a proportioning valve to air the tag and drive axle as a "unit". If it has a separate adjustment, clearly it is easier to adjust.

Also, adding weight to the tag/removing weight from the drive axle shifts weight TO the front axle. So you will need to verify that your front axle is enough underloaded to allow more weight to be added to it.

So, please post each axle's actual weights (individual wheel positions even better) as well as each axle's GAWR.

Then we can see what might be done.

Brett

Sorry about that.

My front axle is rated for 14200 lbs. The rt front tire is carrying 6000 lbs and the left front tire is carrying 6050.

My dually axle is rated for 20000 lbs. The rt dual is carrying 11200 lbs and the left dual is carrying 11650 lbs.

My tag axle is rated for 11000 lbs. The rt tab is carring 2100 lbs and the left tag is carrying 2400 lbs.

My dually axle is over by 2850 lbs.

The air bag system is controlled by HWH controls.

The weighing was done this last July at the Good Sams Rally in Louisville, Ky by the RVSEF, the Recreation Vehicle Safty Education Foundation.

I hope this helps

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Excellent-- that is the information we need.

And yes, you can/should take more weight on tag, which will lighten the drive axle and slightly load the front axle (which is OK-- you have capacity on that front axle. THAT was the critical question!

Hopefully someone else with a CC Magna (what year is it by the way?) can tell you how to adjust the tag. If not, perhaps HWH can enlighten you.

And if you are going to another location where RVSEF will be weighing, if the adjustment is not too difficult, you might reweigh and perhaps, with Walter Cannon's permission, even put it on the scales and make the final adjustments. Worth contacting him-- he is good people (Walter and I along with Gary Bunzer were on the "Ask the Expert" panel at the Redmond FMCA): http://www.rvsafety.com/

Keep us posted on your progress.

Brett

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I do not own a tag-axle rig yet, so I am interested in knowing if the axles are more than or less than 40 inches apart. If they are less than 40" then the limit to an axle is 20,000 lbs. If they are more than, then the limit is 34,000 lbs. I found this information in the Federal Bridge laws defined here <http://www.ntda.org/LinkClick.aspx?fileticket=NiMFqXy27gw%3D&tabid=115>.

So, even thought your rig may be "rated" on the drive axle to 23,000 lbs, is it not limited to 20,000 on the federal highway system, and if you are overweight, you might have problems traveling on some toll roads (ie Ohio, etc) because they weigh you before you get on?

Please educate me.

Thank you.

//Karl

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I do not own a tag-axle rig yet, so I am interested in knowing if the axles are more than or less than 40 inches apart. If they are less than 40" then the limit to an axle is 20,000 lbs. If they are more than, then the limit is 34,000 lbs. I found this information in the Federal Bridge laws defined here <http://www.ntda.org/LinkClick.aspx?fileticket=NiMFqXy27gw%3D&tabid=115>.

So, even thought your rig may be "rated" on the drive axle to 23,000 lbs, is it not limited to 20,000 on the federal highway system, and if you are overweight, you might have problems traveling on some toll roads (ie Ohio, etc) because they weigh you before you get on?

Please educate me.

Thank you.

//Karl

This statement is confusing Federal Highway weight regulations with the carrying capacity of axle. They have no relation to each other.

Stu

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The tale of the Tag.

Recently visited manufacturer factory for updates on 43' Newmar Essex. During weight and balance check they found tag was carrying no weight and adjusted air bags to provide about 3,500 lbs on each tag wheel or total 7,000 on tag. In Missouri left tag melted the oil cap and lost most lubricant. Replaced oil cap, gasket and oil. Suspicious about excessive weight as this had never occurred in 60,000 miles. Gallup New Mexico melted left tag oil cap again. Called Spartan (K2 chassis). They said tags are really meant to run in the opposite direction but they build them this way so they look "good". apparently toe-in and caster is set up to run opposite direction so the drag causes the bearings to overheat and melt the oil caps. Spartan recommends loosening the bearings. Replaced oil cap, oil and gasket. Stopped in Hesperia, California to find left oil cap melted and now right oil cap leaking. Mobile mechanic replaced left oil cap, oil and gasket, checked outer bearing (OK) and adjusted bearing load by "feel". Redlands, California at Redlands Heavy Truck and RV.

Redlands checked weight. Way over 10,000 on tag, 15,000 weight on main. Removed tag wheels, checked all bearings (OK), replaced all seals, oil caps, oil and gaskets. Reset tag weight to 7,000. Found air dryer problem causing inconsistent air pressures.

Spoke with Essex owner in Pennsylvania who had similar tag weight problems and was stopped by Highway Patrol after going over scale on the highway that caught him overweight on the main. He found tag is adjustable with guage under front hood opening and added weight to tag, then had oil cap problems and overheating bearings.

I suspect Spartan knew of this problem and has been underweighting the tag to reduce overheating the bearings. The correct fix is probably adjusting toe-in and caster to reduce drag and sideslip on the bearings. Correct air pressure to bags. Correct bearing adjustment to allow some play and not overheat.

This coach has always had a porposing problem in the ride and with the tag correctly loaded it tends to keep the front axle from floating as it now has enough weight to hold it firmly against the pavement. All we hear is praise for the Spartan K2 ride but for us it has been a roller coaster.

Newmar needs to get with Spartan and get this fixed for all owners.

Calroadster

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Unbeleavable, A manufacturer knowingly selling units with design & manufacturing defects.

You should send a request for compensation for all your out of pocket to Spartan & Newmar. If they don't pay up then send request for help to RV magaxines and name names.

Isn't the RV industry just wonderful!

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Several issues could be at work here:

1. I have seen bearing end play improperly adjusted-- a dial indicator is needed to set it properly. If the tech just tightens the axle nut (setting end play to zero) it can overheat the bearings and damage the Stemco cap. Most tag axles as well as most front axles have end play specs of .003-.005". Spartan (number below) will be able to tell you the correct end play for your axles.

2. You need to insure that there are no bent or malfunctioning parts in the suspension control system-- ride height valves, their control rods, etc.

3. I strongly suggest you call Spartan customer support at 800 543-4277. Work through determining the proper weight distribution for your coach, the diagnosis and resolution of your issues with them.

Please keep us posted.

Brett

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If there isn't enough weight on the tag can it cause the drive tires to spin or not get the mileage out of the tires?

I think that is my problem.

Please advise.

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If there isn't enough weight on the tag can it cause the drive tires to spin or not get the mileage out of the tires?

I think that is my problem.

Please advise.

Welcome the the FMCA Forum.

This isn't something you (or anyone else) should be guessing at. You need to use scales to balance the loads between the axles-- individual wheel position scales are best, but even the scales that weigh each axle will get you close. Remember, changing the tag axle load not only affects the drive axle and tag axle, but also the front axle.

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Back to the saga of the tag axle sight-gauges leaking oil. After replacing both inner and outer left and right axle seals and adjusting the weight to specs as follows:

ADJUST RIDE HEIGHT TO SPECS TO ACHIEVE PROPER WEIGHTS

LEFT RIGHT TOTAL AXLE %

FRONT 6400 6600 13000 94.9 %

REAR 6800 6700 13500 67.5 %

TAG 4000 4350 8350 83.5 %

TOTAL 17200 17650 34850 79.7 %

We proceeded to travel about 1,000 miles returning to base in April, 2011. Preparing for trip on May 09 and found left rear tag oil sight-gauge distorted, bulging, strings of melted plastic material protruding from space between the outer hub plate that contains the plastic-windowed sight gauge and the axle hub itself. Right side oil gauge appeared unaffected. Not enough time to repair again so convinced mechanics at storage barn to adjust weight on tag to attempt to reduce heat on the bearings. Adjusted air pressure to tag axle to 80# and traveled 2,500 miles checking sight-guage and refilling as needed. The entire wheel and tire now greasy and filthy.

June 03 returned to Redlands Truck for another round of "fix the tag leak" game. Techs suspect when tag is lifted when for a sharp trun , it may be returned to it's "loaded" position with more weight than is applied when weighed in a static position. Pure speculation. Will again speak with Spartan in Michigan with these facts and request support. We are curious about other owner's experience and if anyone out there has found a solution to this recurring problem. Otherwise the coach is trouble-free except for the dozens of small squeaks, rattles and chatters.

Thank you,

CalRoadster

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CalRoadster,

Were this my coach, I would lessen the weight on the tag from the numbers you posted. As much to lighten the front axle and load the rear axle as to affect the tag itself.

Be sure they check the bearing end-play with a dial indicator gauge when redoing the tag bearings.

Brett

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I had my 42" Monaco Dynasty regal weighed July 08 in St Paul by RVSEF. He said your tag is way too light drive around and stop and turn up the tag air pressure valve in the rear about 5 lbs. I than reweighed and had 13,100 front 18,300 drives and 5,900 on the tag. 37,300 total on a rig speced at 44,600 GVWR

I just went in to Precision frame for new tires and alignment this week and they weighed it and now I have 13,900 front, 16,750 drives and 8,250 on the tag. 38,950 We have 1600 lbs more stuff in the coach but after he set the tire air pressure to match the loads and the tire mfg load spec sheets it handles a lot better with proper air pressures for the actual load carried. I was just taught that air pressure can be both too low or too high, it should actually match the load spec sheet and if you want you can add up to 10 lbs for safety above what is actually on the fact sheets.

My country coach had a procedure in the owners manual for adjusting the load on the tags.

Good luck I know when we work the seminars in Madison RVSEF will accept signups on Wed for weighing rigs there.

Don Updyke

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General tag principles:

Drive :tag ratio is usually ~60:40 eg 20,000:14,000 (which gives 34,000 combination max)

For a 45 ft coach adding 1000 lbs to the tag, removes 750-800 from the drive axle and adds 200-250 to the steer axle.

The DOT rules are -for RV's 20,000 maximum load on any axle. and 34,000 total for the drive + tag combo. . Having a rating over 20,000 is fine, just more robust and may be a result of using the same chassis for Transit buses (eg Prevost)which have some different limits. Also , having a higher capacity Drive is reasonable since the tag is often lifted resulting in more drive loading.

Ross

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Rmackillop:

Tha ratio would never apply to most of the units on the road. For instance: Any of the Monaco 42 ft. units will have about 8000 on the tag and slightly under 20,000 on the drive Setting the tag to 40% of the total would be about 11,200 on the tag. This would make the front axle so far overweight you would blow front tires! Most of the other 42 ft. units would be in the same boat. Are you the fellow with the Blubird? If so you know all about FA overloads!

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Moisheh,

Really, the ratio does apply to all the tag axles on the road. In that the manufacturer screwed up their engineering and have to lighten the tag to try to keep the unit safe (ie not overloaded on the most critical axle) is a serious shortcoming. If you read the CCC of these coaches, it includes the rated capacity of the tag so obviously to get to that tag loading , the owner would have to put most of the weight on or behind the drive axle.- good luck.

Note that the maximum allowed load for any axle (DOT ) is 20,000 and for a tandem (drive plus tag) the max is 34,000. Therefore the ratio is approx 60:40 to get full use of the combination.

Also see the great specs of the new Foretravel. Approx 4200 capacity without taking the drive over 20,000 ( rating is 23,000)

Rmackillop:

Tha ratio would never apply to most of the units on the road. For instance: Any of the Monaco 42 ft. units will have about 8000 on the tag and slightly under 20,000 on the drive Setting the tag to 40% of the total would be about 11,200 on the tag. This would make the

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