2 sets rear axles ?

Some bus conversions that used to be Crown 40'school buses had two rear axles that were geared. Buses were ten speed.
Tags of any kind are for more carry capacity. Not sure about the previous post about a sway bar. My coach has a sway bar and it does not have a tag.

RetiredHoser wrote:
Hi,

while browsing for a Class A unit I have seen some that have 2 rear axles. Actually I have seen this on a couple of C class units.Is there any real benefit of this setup. Are both axles drive axles ?

thanks

When you see two rear axles on a class A only one is a drive axle. On a class C (I assume we are talking truck conversions) sometimes they are both live axles.

Bill,

Actually both statements are correct.

There were some gas coaches where the limit was pushed by the addition of a tag axle. Both Workhorse and Ford addressed this in the late 1990's by increasing GVWR's to accommodate heavier coaches.

But, those early gas coaches are really unrelated to the larger diesel coaches that were designed from the ground up with a tag axle.

Would I own one of the early tag axle gas coaches-- NO. Would I rule out a diesel because of a tag-- NO. On a diesel it is often a tag or inadequate CCC.

trop-a-cal wrote:
Many times it's because the factory unit is under designed for the length and weight of the built living area. It does have advantages, as most tax axles have separate braking systems which add to stopping and towing ratings. It also eliminates any lateral sway as the tag has an equalizer sway bar.

Not sure where you get the info that somehow the factory unit is under designed. Ever seen a tour bus headed down the road? Think they were all "under designed" so someone add a tag axle?
It nothing more or less than a way to provide additional load carrying capacity which is designed into the chassis when built.
If one rear axle can carry 15,000 pounds, a tag axle can generally add 1/2 again that carrying capacity. The down side to a tag axle occurs when you drive on a toll road! If you have a tag and you are towing, you have the same number of axles that an 18 wheeler has and you will usually pay the same toll. Ouch!
I just came across the Tacoma Narrow bridge a couple of days ago and it cost me $13.50.

Thanks ! Now that I know the answer, that was probably a dumb question.

Just take a ride in one and feel the difference.

Many times it's because the factory unit is under designed for the length and weight of the built living area. It does have advantages, as most tax axles have separate braking systems which add to stopping and towing ratings. It also eliminates any lateral sway as the tag has an equalizer sway bar.

More axles=more tires. More tires=greater weight carrying capacity.
Usually, one of the rear axles has single tires and is not a drive axle.
It is called a "tag axle"; it just tags along.