SO a dealer recently told me while I was looking at a 2014 Providence that the tag axles no longer dump their airbags when put in reverse as in previous years.I did a little searching here and could not find a thread on it so I am asking. Is this true?

I would call the chassis mfgr directly and ask them.

I know there are new rules being phased in some jurisdictions that require all lift axles to be steering units, not fixed. Maybe eliminating the lift function is a way around the steering requirement.

Last week I watched Freightliner (they claim they make 80 percent of motorhome chassis) try and load their 45' bare chassis on a rollback trailer. The hitch would not have been dragging in the dirt if the tag axle had not deflated and the drive axle would have spun even sooner if it was inflated. A manufacture could spec a tag axle without the more expensive ride height valve and wiring that lets it dump the tag axle air in 1st, 2nd and reverse. In looking at new, really heavy, big motor homes recently,I was surprised how many had steerable tag axles. Actually I should not have been surprised as taking the weight off a tag axle that has up to 17,000 pounds on it would severely overload the rear axle.*Even though my tag axle lifts, I really raise it unless I'm doing multiple hard turns. In 80,000 miles I have not seen any extra wear on the tag tires plus they age out before they wear out. One that did not release the tags air pressure would not be a dealbreaker for me.

Some will dump in reverse. Others you hit the "Tag" button on the dash to dump giving you the option. Doug

This dealer told me that freightliner was seeing higher than normal failures in drive axles and they felt it was due to the dumping of the air suspension on the tag axle while backing up. This does not pertain to tag axles that can turn.

Dealer says: Tag axles dont dump anymore. | Good Sam Community

moisheh
Explorer
Feb 13, 2017
Thanks; Your image in that last post does not show.

Moisheh
Ivylog
Explorer III
Feb 12, 2017
Once you can back up while towing it's hard to go back to not being able... reason for building a wheel lift for the Prius. Since the Prius runs it was easier to use ramps to put it into the lift instead of having it raise/lower hydraulically. I already had three receivers so making something that is cantilevered off the back was fairly easy. There are two small wheel to hold it up when going through dips and it does fold up against the back of the MH when needed for a tight site.
Ventureman
Explorer
Feb 12, 2017
Thanks for the explanation
moisheh
Explorer
Feb 12, 2017
Ivylog:

Can you explain that setup on your Prius?

Moisheh
Ivylog
Explorer III
Feb 12, 2017
Dumping let's all the air out of the two airbags on the tag axle. Lifting does that plus there a two air chambers at inflate and lift the tag off the ground. Even though mine lifts, the 1500 lbs the tag axle and tire weight is not enough to cause any appreciable tire wear if it does not lift. I only lift if I'm going to make several sharp turns.
diplomatdon
Explorer
Feb 12, 2017
On the gravel trucks I have driven with drop not tag axle, should work the same way they were ale steerable, however if you didn't lift them when backing up they cocked hard one way or the other and skidded the tires. Probably wouldn't wear them out however could leave small flat spots. One of the questions I plan on asking at the Good Sam RV Show in Phoenix in two weeks.
Ventureman
Explorer
Feb 11, 2017
Dumb question...new to DPs. What IS the difference between dumping air and lifting? Trying to learn...!
two-niner
Explorer
Feb 11, 2017
Our 2012 Tour (freightliner chassis) dumps the air but there is NO LIFT.
dons2346
Explorer
Feb 11, 2017
Dealer doesn't know what he is talking about
Mile_High
Explorer
Feb 11, 2017
My Freightliner has auto and manual dump, but no lift. Lift and dump are two different things.