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Tag axle pressure


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Had my coach weighed at the gathering, thanks to Scotty and his helpers, and it seemed very heavy on the front axle.  Weight is almost to the max recommended and I have nothing in the front bay.  The tag seemed to be heavier than I thought it should. Made me wonder if maybe the tag pressure was too high but I didn’t have any idea what that should be set on.  I knew the gauge was there but just figured it was set from the factory. Ask Dave Pratt during the round table and he said it should be 50-60 PSI.  Before leaving Lazydays this morning I checked and mine was set at almost 80 lbs.  I reduced the pressure and cycled, getting it down to just under 60.  May be my imagination but Seems like it may have softened up the front suspension some on the bad bumps.  I look forward to weighing it again now to see if maybe it took some weight off the front axle.  I know this may be elementary but maybe someone in the group can use this information.  I learned so much I at the gathering.  Thank you Dave for putting it together, Van for the suspension presentation, for the vendors who shared information and for all the members that were so generous with information.

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I run mine around 47. You really need to weigh it after adjusting regulator. When reducing tag pressure, more weight is transferred to drive axle. I prefer more percentage of the weight on the drivers than the steer axle. It is literally a balancing act, adjusting it back and forth until you get it where you want. Hope this helps.

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1 hour ago, Ivylog said:

What were your axle weights and 80 is almost double what I run. 

Ivylog

my steer axle is 14,890

drive axle 17,520

tag 11,400

have it down to just below 60psi now so will need to weigh it again

1 hour ago, Ivylog said:

What were your axle weights and 80 is almost double what I run. 

Those weights were with the gray and black tanks at least 2/3 full and 3/4 tank of fuel.

it would be nice if there were a guideline of what percentage of weight should be on each axle and try to work towards that 

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56 minutes ago, Frank Bergamo said:

I run mine around 47. You really need to weigh it after adjusting regulator. When reducing tag pressure, more weight is transferred to drive axle. I prefer more percentage of the weight on the drivers than the steer axle. It is literally a balancing act, adjusting it back and forth until you get it where you want. Hope this helps.

Does reducing the tag pressure take any weight off the steer axle?

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15 minutes ago, Daryl Ammons said:

Does reducing the tag pressure take any weight off the steer axle?

Yes. That’s why you need to weigh each time you adjust the regulator. Look at your placard to the left of your seat. Your axle maximum’s will be listed there. Using your actual  axle weights, determine the percentage of the maximum weights on placard. I prefer more percentage on the drive axle than the steer axle. The tag will be way under maximum, don’t pay to much attention to the tag, focus on the steer and drive axle. Hope this helps.

Edited by Frank Bergamo
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Previous owner of our Executive was told by the fine folks at Brazel's, that while sitting at the scale with the front axel only on the scale, run the tag up until you have ~14k lbs on the front axle (yours may be different) and leave it there unless you significantly change the weight/load in the coach. For me that's about 65 psi on the tag and I have no complaints with how the coach drives. I could keep it going straight down the road with one finger on the wheel (if I was so inclined). He also told me that before doing this, driving the coach was exhausting and the tag was set to about 35 psi.

Edited by turbochaz
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43 minutes ago, turbochaz said:

Previous owner of our Executive was told by the fine folks at Brazel's, that while sitting at the scale with the front axel only on the scale, run the tag up until you have ~14k lbs on the front axle (yours may be different) and leave it there unless you significantly change the weight/load in the coach. For me that's about 65 psi on the tag and I have no complaints with how the coach drives. I could keep it going straight down the road with one finger on the wheel (if I was so inclined). He also told me that before doing this, driving the coach was exhausting and the tag was set to about 35 psi.

Well, using that method, depending where Monaco installed the heavy appliances / tanks, you could end up with a overloaded tag axle, and your strongest axle with 4 wheels, carrying 16,000 lbs, when it's rated for 21,000 lbs!

My coach is slightly above 14,000 on the steer axle with 45psi in the tag axle bags.

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Well, like I say, this is all from memory (which has been known to let me down) and I don't have the coach nearby, but looking at the brochure, it says 15F, 23D and 10T. so I must be more like 9K on the tag. I know that last time I weighed it, it was all within the capacities and we haven't made any significant changes to the load.

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With a ISL your drive axle is rated 20K and tag 10K (23/12 with a ISM). Unfortunately all the big Monacos are heavy on the front axle and to take as much weight as possible off it you need to load the drive to its max (20K) by reducing the tag’s airbag psi. I would use 40 psi when you weigh next, based on 80K mikes on a 42’ Dynasty weighing many times. These things have a way of gaining weight so I would shoot for 19K on the drive.

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Yes

19 hours ago, Daryl Ammons said:

 Before leaving Lazydays this morning I checked and mine was set at almost 80 lbs.  I reduced the pressure and cycled, getting it down to just under 60.  May be my imagination but Seems like it may have softened up the front suspension some on the bad bumps.  

Yes, reducing the weight on the front will reduce the harshness of the ride. With 15K on the front you needed 120 psi in your 295s. Once you get the front below 14K (it’s rated 14,600) you’ll likely need 110 and 85 in the drivers, and 75 in the tags.

I run 315s on the front because I can reduce by 10 psi what’s need to carry the weight… softening the harshness. I run 11Rs on the rear but they require 10 psi more to carry the same weight as a 295… not a problem on the rear and they are the same diameter.

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This is the weighing process i was given at many FMCA Rallyswhile full timing 10 years. Be sure to keep your engine running to maimtain ride height. 

I had the Tag pressure so i had 15K on our 07 Executive, with 315's al the way around. As you burn fuel you reduse the steer axle weight. 

Weigh the coach. Four , or Six corner weight is the best, but single axle weights will be OK too. Fuel and water full. Black and grey tanks empty with your stuff on board. CAT scales at many truck stops. Tell the clerk you want to weigh a coach. There is an intercom at the scale so you can communicate with the clerk. There will be 3 platforms for3 axles. Steer axle on the  first, Drive on the second, and if applicable, Tag on the third. Keep the ENGINE Running, so you stay at Ride Height.Get the print out from the clerk. IF you have a tag axle, you may have to adjust your DOWN pressure to move weight as needed, and after adjusting your down pressure on the tag, REWEIGH the coach.  Now go to YOUR tire Mfg. inflation charts for the correct COLD inflation.

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7 hours ago, Ivylog said:

Yes

Yes, reducing the weight on the front will reduce the harshness of the ride. With 15K on the front you needed 120 psi in your 295s. Once you get the front below 14K (it’s rated 14,600) you’ll likely need 110 and 85 in the drivers, and 75 in the tags.

I run 315s on the front because I can reduce by 10 psi what’s need to carry the weight… softening the harshness. I run 11Rs on the rear but they require 10 psi more to carry the same weight as a 295… not a problem on the rear and they are the same diameter.

No problem with clearance with the 315’s?

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On 2/20/2023 at 7:00 PM, Daryl Ammons said:

Had my coach weighed at the gathering, thanks to Scotty and his helpers, and it seemed very heavy on the front axle.  Weight is almost to the max recommended and I have nothing in the front bay.  The tag seemed to be heavier than I thought it should. Made me wonder if maybe the tag pressure was too high but I didn’t have any idea what that should be set on.  I knew the gauge was there but just figured it was set from the factory. Ask Dave Pratt during the round table and he said it should be 50-60 PSI.  Before leaving Lazydays this morning I checked and mine was set at almost 80 lbs.  I reduced the pressure and cycled, getting it down to just under 60.  May be my imagination but Seems like it may have softened up the front suspension some on the bad bumps.  I look forward to weighing it again now to see if maybe it took some weight off the front axle.  I know this may be elementary but maybe someone in the group can use this information.  I learned so much I at the gathering.  Thank you Dave for putting it together, Van for the suspension presentation, for the vendors who shared information and for all the members that were so generous with information.

Basic physics.  Like lifting a wheelbarrow.  You kick up the tag.  You shift weight to the front.  NOT GOOD.  The untold story, and we have caravaned  with folks that made the same mistake….they overloaded their tag. Kicking up the weight also will accelerate failure of a tag tire as the drive is just cruising along and not carrying it’s weight.  One only got 100 miles from the dealership (almost new Imperial or Navagator)…  blew a rear and was “most distraught”.  Dealer bought the tire….

I personally would lower the pressure to what other Dynasty owners run.  Then find a CAT scale with no guard rails.  Make several passes so get weights on each axle….as in all three axles.  Then, you drive on where you only put one side on the scale.  Then subtract the single from the dual.  That gives you the corners,

The standard practice is to have a 3/4 or so full fuel and maybe 1/3 water if your fresh is up front,  my Camelot runs heavier as to the arrangement of the tanks.  Most Dynasty owners report lower weights.  No offense to the portable scales, but the most reliable and accurate weights come from CAT scales.  Many moving companies have scales on site.  

I run close to max in the front and maybe 10 pounds less in the rears…even lower if I had a Tag.

Many have experimented with 315.  Typically the Michelins run smaller as in a lower tread patch.  Some folks tried 315’s and found they did scrub.  Others, David in particular, ran them. Careful measurement is critical and you have to check at both ends….and many points in between as Monaco did some “unusual things”.  We had many folks, several years ago, that upgraded….sort of the “accessory of the year” syndrome.   Once someone bragged It, then others tried and said it was great.  But there were maybe 10% - 15%  that had to go back and downgrade.  Don’t know what they did about “gee….this don’t work….need my $$ back”.  Their experiences sort of soft pedaled the upgrades and the differences in ride quality were negligible.

Get HARD data….you might even back off 5 PSI or rewieigh and get your weights even and also balanced.

Just some feedback on the trends and the “weights” over the years….

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23 hours ago, Tom Cherry said:

Basic physics.  Like lifting a wheelbarrow.  You kick up the tag.  You shift weight to the front.  NOT GOOD.  The untold story, and we have caravaned  with folks that made the same mistake….they overloaded their tag. Kicking up the weight also will accelerate failure of a tag tire as the drive is just cruising along and not carrying it’s weight.  One only got 100 miles from the dealership (almost new Imperial or Navagator)…  blew a rear and was “most distraught”.  Dealer bought the tire….

I personally would lower the pressure to what other Dynasty owners run.  Then find a CAT scale with no guard rails.  Make several passes so get weights on each axle….as in all three axles.  Then, you drive on where you only put one side on the scale.  Then subtract the single from the dual.  That gives you the corners,

The standard practice is to have a 3/4 or so full fuel and maybe 1/3 water if your fresh is up front,  my Camelot runs heavier as to the arrangement of the tanks.  Most Dynasty owners report lower weights.  No offense to the portable scales, but the most reliable and accurate weights come from CAT scales.  Many moving companies have scales on site.  

I run close to max in the front and maybe 10 pounds less in the rears…even lower if I had a Tag.

Many have experimented with 315.  Typically the Michelins run smaller as in a lower tread patch.  Some folks tried 315’s and found they did scrub.  Others, David in particular, ran them. Careful measurement is critical and you have to check at both ends….and many points in between as Monaco did some “unusual things”.  We had many folks, several years ago, that upgraded….sort of the “accessory of the year” syndrome.   Once someone bragged It, then others tried and said it was great.  But there were maybe 10% - 15%  that had to go back and downgrade.  Don’t know what they did about “gee….this don’t work….need my $$ back”.  Their experiences sort of soft pedaled the upgrades and the differences in ride quality were negligible.

Get HARD data….you might even back off 5 PSI or rewieigh and get your weights even and also balanced.

Just some feedback on the trends and the “weights” over the years….

"The standard practice is to have a 3/4 or so full fuel and maybe 1/3 water if your fresh is up front

Tom could you elaborate on that statement. I have never heard of that before. All the Seminars i have attended , FMCA and M I. specified the formula in my prior post.  

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2 hours ago, Paul A. said:

"The standard practice is to have a 3/4 or so full fuel and maybe 1/3 water if your fresh is up front

Tom could you elaborate on that statement. I have never heard of that before. All the Seminars i have attended , FMCA and M I. specified the formula in my prior post.  

My standard practice.  I did the full fuel tank and full fresh tank.  Even shifting DW’s stash of food and canned drinks and water to the back bay.  Best I could come up with was I had maybe 5% pad or safety from the rated weight.  That is with the recommend. 115 PSI which corresponds to the axle rating.  However, 115 is a bit too harsh.  So, I rarely run with a full tank and full water and all the gear and food we take on long trips.  So I run about 3 PSI less.  But if I am going to a basketball tournament, where I need a full water tank, I usually let the fuel run down as we have 50A service.  When we did the ABQ, I used full 115….then dump the tanks and w3 have very little water.

So, my SOP IS the real world.  Knowing how engineers and lawyers require worst case scenario.  Since I run a Pressure Pro Pulse, I know what is going on….as well as watching the “run pressure” and knowing if I hit, on a hot day, a certain pressure, I back off on my speed.

One needs to assess how one will be loaded and then used common sense.  I typically cruise at 62.

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