Tag axels... why?

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scottydl

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In my quest for a used MH, I've run across several models (usually Holiday Ramblers) that have tag axels.  What's the point?  Keep in mind these are on units under 30'.  Seems like all a tag axel would do is require me to buy 8 new tires instead of 6.  ::)  They look kind of cool but I can't see any other advantage.  Please educate me!  :)
 
A tag axle is usually used on larger motorhomes to keep the weight on the drive axle to 20,000# or less, the legal limit in most states.  On smaller motorhomes, the only reason I can think of is the coach manufacturer is trying to put more weight on the chassis than it was designed for.
 
Scotty:

RV manufacturers add tag axles to increase the GVW of the chassis. An additional benefit of the additional axle is to shorten the rear overhang, distribute  weight forward, and to stabilize the "tail-wag" of RV.

All this has a cost, more cost, maintenance and less storage.
 
In addition to what Jeff says, a tag axle rig will also ride a bit better, because a side effect is to reduce fore & aft pitching when you cross RR tracks or bumps.  They don't put tags on for that reason, but its a side benefit.

All that said, a tag on a 30 foot RV is simply to add weight capacity to the chassis.  My guess would be these 30 footers you mention are built on "stretched" light truck chassis, possibly stretched in length and surely stretched in GVWR. When coach builders cannot get a hefty enough chassis for the size body they are adding, at a priced they feel is  reasonable, they sometimes start with a lighter duty chassis and add a tag and perhaps extend its length too. This happened often in the late 80's and early 90's, when coach sizes were growing faster than the available chassis.
 
Just adding a tag axle doesn't mean a safe increase in GVWR.  The chassis manufacturer designed the chassis to carry a specific gross weight based on a lot of factor besides the drive axle.  If the suspension, brakes, and drive train aren't designed for the additional weight, adding the tag axle is dangerous.
 
You gents are all right in all aspects \With that said I have a 37 1/2 ft MH with tag and love the tag for it's stability and ride in comparison with other units appoxinmately the same size.  Especially in the mountains and pulling a trailer.  Works for me others it may not. 
 
My old mh was a 27' class c. It handled and drove extremely nice. I was glad the tag was there. The only time i could of done with out the tag was in mud. The tag will take some traction away from the drive tires. If you have good drive tires it's not that bad.
 
One common misconception is that the addition of a tag axle to a chassis that did not have on originally will increase the load carrying capacity.  Adding a tag axle does not increase the GVWR.  To increase the rated GVWR would take authorization from the chassis manufacturer after they coordinate with their vendors for the affected components that are affected.  This effort is not easily achieved or accomplished very often.

However it is true that adding a tag axle may, but not always, improve vehicle stabilization
 
I'm certainly no expert on this subject but I do have an observation to pass on.? ?I drive a '97 Bounder 34V on the F53 chassis.? The coach has a 208" wheelbase with a tag axle.? The newer 34's, 35's and 36's DO NOT have the tag axle but do have a longer wheelbase chassis.? They also have a wider front wheel stance (remember they went from a 96" to 102" standard back then).
My coach is 102" wide on the older narrow chassis.? (Don't you just love transition years ?)

My observation:? (I have driven several older coaches)

With the tag axle, my coach handles as good as (maybe not better than) the newer units in heavy traffic at highway speeds whether towing or not.? I credit this handling to the tag axle since some of the older narrow coaches without tags seemed squirrely in these situations.? Am I wrong?
 
If you get a coach designed around a tag axle that can be lifted, you get the best of all worlds.  You can raise the tag to gain traction in mud and since the drive axle is usually more forward, raising the tag shortens the wheel base and make maneuvering in tight spaces easier.  All that being said, I'd stay away from tag axle coaches that don't have the ability to lift the tag axle.  Its a good way to get hung up if you jump a curb and end up taking the load off your drive axle...most embarrassing to have to call a tow truck for a 6 inch tow.
 
I've taken our tag into places that you couldn't believe and never got hung up.  Maybe it's the driver and not thr tag. Beside I tow  24' enclosed trailer that makes it more difficult.  Not saying I haven/t had problems,but not due to the tag.  That theory don't fly with me.
 
Not all RV owners are as perfect.  Its not a theory, it is a fact that you can take the load off the drive axle with a tag.  Ask some tow truck operators what they have seen.  If you never make a mistake then ignore all advice.
 
Oh  I make mistakes but when you've invested big $ in an RV why risk damaging it or abusing it.  Sometimes it takes a little common sense when usinf equipment, knowinf your ab ilities and units ability.  There's always someone that won't abide by common sense.
 
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