[Tom]

When you flip the switch you remove the load capacity from the tags and the load is shifted to the drive wheels. The bus will temporary sink until the leveling valves catch up with the air pressure needed in the drive axle air bags. Bob

[Bob]

thanks bob. just got back from holidays sorry i didnt reply sooner.

petar

[Roger]

Keep in mind that your going from 6 bags to 4 to keep the bus level, it takes more pressure. Your tanks could be on the low end right before the compressor kicks on. As long as it’s for turning tight corners, it’s fine.

[Archived]

Lifting the tag axle is over rated. I cannot remember the last time I lifted a tag axle.

It may shorten the turn radius by a small amount when it is lifted but I can’t say it does or how much. It would be a good experiment in a big, flat empty parking lot to test and quantify the benefit. I realize the effect is that of shortening the wheelbase, but in so doing weight from both the tag and the steer is transferred to the drive axle, so while the tag axle scuffs less because it is lifted, the steer scuffs more due to the small weight transfer toward the drive as a result of increased rear overhang.

Has anyone actually measured the change in turn radius?

[Bob]

I always lift mine when turning on my cement drive. Saves the wife from complaining about the black streaks!! 🙂

I did leave them down one time and stopped in the middle of the turn and I did not like the way the tag wheels were leaning to one side. It put a lot of pressure on the tire sidewalls so I know it is scuffing them. That is one complaint Eagle owners have with the bogie axles is the dragging of them on tight turns.

[AL]

when the ground gets wet or muddy and you find yourself off pavement lift it up first before moving and just might save yourself a tow bill. Also in snow. Actual experience. Bob ps puts the traction on the drive wheels where required. All the tags do is hold weight up.

[Archived]

I agree with Bob about lifting the tag if more traction is required. But when a tag scuffs sideways it is no different than what is happening to the steer tires when the steering wheel is turned fully. Except the steer tires are doing the scuffing with twice the weight on them in some instances. The drive axle is attempting to push the coach forward, the steer tires are resisting it except they aren’t perpendicular to the direction of travel, and the tags are also scuffing, except they are closer to perpendicular to the direction of travel.

My cars leave black marks on the driveway when I steer sharp.

But to the original question about the rear dropping and not raising when the tag is lifted no one of us can state the time it takes to raise the rear, or how much the rear drops because those pieces of information are dependent upon a number of things, not the least of which is the weight of the coach. On my first coach the tag axle weighed about 7000 pounds and the drive was about 19000. So in order for the four drive axle air bags to return the coach to drive height the pressures in the air bags had to increase enough to carry 1750 pounds of additional weight each.

On the second coach the tag carried about 11,000 pounds so the four drive axle air bags had to lift an additional 2750 pounds. Obviously the additional air pressure per air bag was much greater and therefore the time to pressurize was greater.

As a piece of junk information I was playing with air pressures when I added my shut off valves to the house air circuits. I found on my coach it takes approximately 80 PSI to bring the rear to drive height, and approximately 105 PSI to bring the steer axle to drive height. For those who want to set the aux compressors to pressures necessary to keep the coach level find your pressures and use that information to set the compressor cut in / cut out pressure.

[Davy]

On my last coach, a 42-foot Beaver Contessa, I always used my tag lift. On it, you could set it to automatically lift automatically when the coach was below 5 mph. That feature I did not use.

On my current coach I used it a few times at the beginning and haven’t since. The few times I did use it the coach lost too much height in the rear. I did wait a couple minutes once to see if it would return to normal ride height and it did not. So, for now at least, the tag lift switch gets no use.

[Bob]

On my 95/96 XL the tag pressure is eased a little automatically when I make a turn at slow speeds in order to shortent the turning radius. It does not completely “lift” the tag. In fact the manual says, “Note: The manual valve for tag UP or DOWN is independent of the “Tag axle automatic unloading system”.

I have a switch that can cancel that function and I often use it if there is a change in elevation in the turn and I fear I may drag the rear end if it drops any.

Jon, I do think it affects the turning radius a little but that may just be my perception because of what I read in the manual…

When I first bought the bus I asked my contacts in the entertainment industry about it and they said they had never seen such a switch. I found out when I read my manual that only the XL-45 has it. The XL-45E does not have it in that vintage.

Is this in the later coaches?

DKO

[David]

Mine has tag lift. dumps air bags on tags and lifts tag wheels . Bob

[Archived]

Sorrry, Bob, I should have been more clear. I suppose that most of us with a tag axle have the capability to lift it. I was asking who has the “Tag axle automatic unloading system” and the Cancel button.

DKO

[Fred]

I believe all 45 foot coaches automatically dump tag air (or can have that capability) by virtue of a “cam” from the steering linkage when the steering wheel is turned to the extreme in either direction. My 45 foot 97 had that feature, but in addition there were a limited number of coaches that had “stabilizators” that were actually hydraulic cylinders much like a shock absorber that supported the rear of the coach when the tag axle air was dumped. I know my 97 coach had that feature, Hector’s has that feature and possibly JIM’s coach has that feature.

I am not aware of any 40 foot coaches that automatically dump tag axle air when making sharp turns. The feature does not raise the tag but just dumps air bag air.

If anyone has a 45 foot coach and wants to see if the coach has the automatic tag air dump feature, drop the front bumper and look up infront of the area of the steering column. There is likely going to be a rectangular stainless steel component that travels when the steering wheel is turned from full left to full right. At the end of the travel the stainless steel part (either direction) the part contacts a lever arm on a switch which initiates the automatic dumping of tag axle air.

[Fred]

My 2000 CC didn’t have the auto dump, so I suppose it was an option.

[Dale]

How do you know. Not trying to break your chops, just to note the only way I know it is there is by looking for the switch and actuator “cam”.

It is not noticeable when driving the coach because with the noise of the engine you will not know it is dumping tag air.

[Don]

Not on this one I just re-did all the air system. Been all the way thru it! Hope never to repeat..Lines norgen,coils ,leveling valves,and airbags. I think 98 is first year it doesn’t dump tags when you hit level low. DKO said he dumps air on tags before leveling( Automatic?). I’m no Hector but did learn under fire. Bob