High Inner Drive Tire Temp

[Paul J A]

You do BURN weight as you travel. 

What does #2 diesel weigh per gallon?

       7.09 pounds per U.S. gallon.                 

Diesel 4D: 8 pounds per U.S. gallon.

EN 590 Diesel: 6.96 pounds per U.S. gallon.

[Jdw12345]

4 hours ago, Ivylog said:

A Highway bill in 2013 made 24K axles legal on MHs and Buses. Yes there’s so toll roads in the BE that have a 30 K limit. I turn on the “ truck must enter sign at some weight stations that weigh you on the fly as I blow bye.

I have too, and after 40+ years of trucking I have a grin on my face like you can’t believe!!! 😎

   One other thing I do is actually put my hand on the tires on the drive axle, you can feel if there’s a significant temperature difference!

[96 EVO]

2 hours ago, Paul A. said:

You do BURN weight as you travel. 

What does #2 diesel weigh per gallon?

       7.09 pounds per U.S. gallon.                 

Diesel 4D: 8 pounds per U.S. gallon.

EN 590 Diesel: 6.96 pounds per U.S. gallon.

Absolutely you do (Just watch a Formula 1 race, they do their quickest laps at the end of the race, cause they are light!).

But, in our case, we need to set tire pressures, and axle loading, for max weight!

Edited June 12, 2023 by 96 EVO

[Paul J A]

27 minutes ago, 96 EVO said:

Absolutely you do (Just watch a Formula 1 race, they do their quickest laps at the end of the race, cause they are light!).

But, in our case, we need to set tire pressures, and axle loading, for max weight!

Absolutely

[Tom Cherry]

Partial update.  Frank and I have been working with Moe and getting more insight and talking and such.  He ran the “pre trip” brake and air check that is in the files.  I attached it as a reference for folks.  Nothing abnormal that would have caused a dragging brake issue.

The 2005 Sigs were the transition year for the “disk brake” conversion on the upper ends.  He, therefore, does not have slack adjusters that could be “one of the usual suspects”.

Frank found an online calculator that actually does the same calculations as my spreadsheet.  I found a similar one.  They both returned the same answer.  Here is a link.

https://www.sensorsone.com/gay-lussacs-law-calculator/

you record the TP early in the morning, just after day break so the radiation from the sun has not started to heat up the tires.  Also, record the temperature.  Then drive for an hour or so….not necessarily immediately, but later on.  The tires will be at Thermal Equilibrium.  Record the TP.  Click on the “T2” BOX on the top.  Plug in P1, P2 & T1 and you will get the internal T2 temperature inside the tire.

Moe Will be verifying the individual corner weights…..or the three Axle “gross” or combined tires. As well as one sides data so he can calculate the exact weight that each tire or pair of tires is carrying.

Still some other things to verify and discuss…..and then the conclusions 

 

[Frank McElroy]

On 6/11/2023 at 9:05 PM, Jdw12345 said:

I have too, and after 40+ years of trucking I have a grin on my face like you can’t believe!!! 😎

   One other thing I do is actually put my hand on the tires on the drive axle, you can feel if there’s a significant temperature difference!

I have a TPMS so I don't feel the individual tire temps but I do use a thermal IR heat gun to measure axle hub temperatures at rest stops and as a post trip inspection.  Haven't found any bad axle bearings in over 35 years of driving motorhomes but old habits are hard to break.

[David Pratt]

Tires are a major concern to everyone, whether it be a motor-home, travel trailer, truck, aircraft or even a bike. All of us want to maintain and service our tires to get the most life from them.

I am most conscious about proper tire care, tire inflation, heat, load limits, speed ratings to name a few things of importance. Somethings about tire care are very simple and in most cases other things get more difficult because of lack of knowledge or experience.

Tire Maintenance and Tire Care is always a Discussion we have at the Gathering.

I learned a lot about tires mostly because of my experience in auto racing and maintaining my own aircraft. 

Tom Cherry and Frank McElroy mentioned Thermal Equilibrium. I would venture to say that most folks have never heard of it, let alone understand it. Thermal Equilibrium is the one most important issue we dealt with in our race cars. It alone can determine how the car handles and tire life/wear. Thermal Equilibrium sounds like it is more heat related but, the air pressure in the tire is what regulates it more unless some outside development was in play, such as overheated brakes, bearings, heat from the sun and road surface temperature.

Since I purchased my first Motor Home, my first project was always to weight the coach and establish the correct tire pressures. When TPMS came on the scene it made the job much easier.

One of the methods that is always discussed is to have the coach weighed on all corners and establish the maximum axle weights to establish the correct air pressure for each tire on that axle based on the heaviest corner on the axle. Tires should be inflated to the same pressure on that axle with a minor exception.

Once I have established the Load factors for each axle and the base line air pressure I will take it to the next step which does take time and some driving. This is where Thermal Equilibrium and how it effects tire performance comes into play. I take the coach out on the highway and at highway speed 60 - 65 MPH I travel one hour and log the tire temps, Then again at 1.5 hours and log the temps again at the 2 hour mark and monitor each hour after that.

Under most normal circumstance the one hour mark will be your tire blow up pressure.This is the point where the tire pressure has achieved Thermal Equilibrium. At this point forward your tire pressures should be stable with little change.

That one hour tire pressure(blow up pressure) will be different depending on what air you use to fill your tires. The blow up pressure will be higher if you fill your tires with just air and will be lower if you fill and maintain your tires with Nitrogen. The ideal Blow Up pressure should be no more than +/- 20% max.

The second step is to lower the tire pressures in each tire 2-3psi below the baseline tire pressure in step one and take it on the highway again repeating the first step and logging the temps.

The third step is to repeat the first step again but raise the tire pressure 2-3psi above the baseline tire pressure in step one.

Compare the one hour blow up pressures. If the blow up pressure is higher in step two it indicates a low base line temp. In step 3 If the pressure is lower that would indicate to much pressure. If your using Nitrogen to keep your tires inflated your average blow up pressure will be 12-14% above your base line pressure. If you fill you tires with just air the blow up pressure will be 14-20% higher than you base line pressure. Raise or lower the baseline tire pressure to where your blow up pressure is is with in the percentages and stays stable for the duration of your trip.

An Example; My baseline pressure in my Steer Tires is 115psi and the blow up pressure stabilizes at 128psi. Drive Axle tires baseline pressure are105psi and the blow up pressure is 118psi. The tag axle tires baseline pressures are 95psi and blow up pressures are 107psi. these pressures are consistent whether I am on the road two or five hours.

As noted in prior posts about the inner drive axle tires having a higher pressure than the outer drive axle tires this is not uncommon, there is a lot of heat generated by the engine and transmission being funneled through that area. but a 30% jump above the base line pressure is and indication something else is going on.

When I was doing the tire pressure tests I saw that the inner drive axle tires blow up pressure would be 3-4psi higher than the outside tires. So I started to adjust the inner baseline pressure down until the inner tires would be at the same blowup pressure. My base line pressure on the drive axle tires are; L/Outer-105psi, L/Inner-103psi, R/Inner-102psi, R/Outer-105psi. One hour Blow up pressure is stable at 118psi.

All the tires on my coach are filled and maintained with Nitrogen.

My TPMS also measures heat. I very rarely pay any attention to it. Your tire psi will warn you of a problem with the tire long before the temperature will.

With the race cars the only time we are concerned with the tire temps is when we changed the tires in the pits. We would measure the temps across the tires along with the tread depth. The tires temps would tell us how the tire was contacting the track surface(GRIP) and if we need to make any alignment/suspension adjustments.

[Mocephus]

1 hour ago, David Pratt said:

Tires are a major concern to everyone, whether it be a motor-home, travel trailer, truck, aircraft or even a bike. All of us want to maintain and service our tires to get the most life from them.

I am most conscious about proper tire care, tire inflation, heat, load limits, speed ratings to name a few things of importance. Somethings about tire care are very simple and in most cases other things get more difficult because of lack of knowledge or experience.

Tire Maintenance and Tire Care is always a Discussion we have at the Gathering.

I learned a lot about tires mostly because of my experience in auto racing and maintaining my own aircraft. 

Tom Cherry and Frank McElroy mentioned Thermal Equilibrium. I would venture to say that most folks have never heard of it, let alone understand it. Thermal Equilibrium is the one most important issue we dealt with in our race cars. It alone can determine how the car handles and tire life/wear. Thermal Equilibrium sounds like it is more heat related but, the air pressure in the tire is what regulates it more unless some outside development was in play, such as overheated brakes, bearings, heat from the sun and road surface temperature.

Since I purchased my first Motor Home, my first project was always to weight the coach and establish the correct tire pressures. When TPMS came on the scene it made the job much easier.

One of the methods that is always discussed is to have the coach weighed on all corners and establish the maximum axle weights to establish the correct air pressure for each tire on that axle based on the heaviest corner on the axle. Tires should be inflated to the same pressure on that axle with a minor exception.

Once I have established the Load factors for each axle and the base line air pressure I will take it to the next step which does take time and some driving. This is where Thermal Equilibrium and how it effects tire performance comes into play. I take the coach out on the highway and at highway speed 60 - 65 MPH I travel one hour and log the tire temps, Then again at 1.5 hours and log the temps again at the 2 hour mark and monitor each hour after that.

Under most normal circumstance the one hour mark will be your tire blow up pressure.This is the point where the tire pressure has achieved Thermal Equilibrium. At this point forward your tire pressures should be stable with little change.

That one hour tire pressure(blow up pressure) will be different depending on what air you use to fill your tires. The blow up pressure will be higher if you fill your tires with just air and will be lower if you fill and maintain your tires with Nitrogen. The ideal Blow Up pressure should be no more than +/- 20% max.

The second step is to lower the tire pressures in each tire 2-3psi below the baseline tire pressure in step one and take it on the highway again repeating the first step and logging the temps.

The third step is to repeat the first step again but raise the tire pressure 2-3psi above the baseline tire pressure in step one.

Compare the one hour blow up pressures. If the blow up pressure is higher in step two it indicates a low base line temp. In step 3 If the pressure is lower that would indicate to much pressure. If your using Nitrogen to keep your tires inflated your average blow up pressure will be 12-14% above your base line pressure. If you fill you tires with just air the blow up pressure will be 14-20% higher than you base line pressure. Raise or lower the baseline tire pressure to where your blow up pressure is is with in the percentages and stays stable for the duration of your trip.

An Example; My baseline pressure in my Steer Tires is 115psi and the blow up pressure stabilizes at 128psi. Drive Axle tires baseline pressure are105psi and the blow up pressure is 118psi. The tag axle tires baseline pressures are 95psi and blow up pressures are 107psi. these pressures are consistent whether I am on the road two or five hours.

As noted in prior posts about the inner drive axle tires having a higher pressure than the outer drive axle tires this is not uncommon, there is a lot of heat generated by the engine and transmission being funneled through that area. but a 30% jump above the base line pressure is and indication something else is going on.

When I was doing the tire pressure tests I saw that the inner drive axle tires blow up pressure would be 3-4psi higher than the outside tires. So I started to adjust the inner baseline pressure down until the inner tires would be at the same blowup pressure. My base line pressure on the drive axle tires are; L/Outer-105psi, L/Inner-103psi, R/Inner-102psi, R/Outer-105psi. One hour Blow up pressure is stable at 118psi.

All the tires on my coach are filled and maintained with Nitrogen.

My TPMS also measures heat. I very rarely pay any attention to it. Your tire psi will warn you of a problem with the tire long before the temperature will.

With the race cars the only time we are concerned with the tire temps is when we changed the tires in the pits. We would measure the temps across the tires along with the tread depth. The tires temps would tell us how the tire was contacting the track surface(GRIP) and if we need to make any alignment/suspension adjustments.

David thank you for that. Great info!!

[Frank McElroy]

5 hours ago, David Pratt said:

Tires are a major concern to everyone, whether it be a motor-home, travel trailer, truck, aircraft or even a bike. All of us want to maintain and service our tires to get the most life from them.

I am most conscious about proper tire care, tire inflation, heat, load limits, speed ratings to name a few things of importance. Somethings about tire care are very simple and in most cases other things get more difficult because of lack of knowledge or experience.

Tire Maintenance and Tire Care is always a Discussion we have at the Gathering.

I learned a lot about tires mostly because of my experience in auto racing and maintaining my own aircraft. 

Tom Cherry and Frank McElroy mentioned Thermal Equilibrium. I would venture to say that most folks have never heard of it, let alone understand it. Thermal Equilibrium is the one most important issue we dealt with in our race cars. It alone can determine how the car handles and tire life/wear. Thermal Equilibrium sounds like it is more heat related but, the air pressure in the tire is what regulates it more unless some outside development was in play, such as overheated brakes, bearings, heat from the sun and road surface temperature.

Since I purchased my first Motor Home, my first project was always to weight the coach and establish the correct tire pressures. When TPMS came on the scene it made the job much easier.

One of the methods that is always discussed is to have the coach weighed on all corners and establish the maximum axle weights to establish the correct air pressure for each tire on that axle based on the heaviest corner on the axle. Tires should be inflated to the same pressure on that axle with a minor exception.

Once I have established the Load factors for each axle and the base line air pressure I will take it to the next step which does take time and some driving. This is where Thermal Equilibrium and how it effects tire performance comes into play. I take the coach out on the highway and at highway speed 60 - 65 MPH I travel one hour and log the tire temps, Then again at 1.5 hours and log the temps again at the 2 hour mark and monitor each hour after that.

Under most normal circumstance the one hour mark will be your tire blow up pressure.This is the point where the tire pressure has achieved Thermal Equilibrium. At this point forward your tire pressures should be stable with little change.

That one hour tire pressure(blow up pressure) will be different depending on what air you use to fill your tires. The blow up pressure will be higher if you fill your tires with just air and will be lower if you fill and maintain your tires with Nitrogen. The ideal Blow Up pressure should be no more than +/- 20% max.

The second step is to lower the tire pressures in each tire 2-3psi below the baseline tire pressure in step one and take it on the highway again repeating the first step and logging the temps.

The third step is to repeat the first step again but raise the tire pressure 2-3psi above the baseline tire pressure in step one.

Compare the one hour blow up pressures. If the blow up pressure is higher in step two it indicates a low base line temp. In step 3 If the pressure is lower that would indicate to much pressure. If your using Nitrogen to keep your tires inflated your average blow up pressure will be 12-14% above your base line pressure. If you fill you tires with just air the blow up pressure will be 14-20% higher than you base line pressure. Raise or lower the baseline tire pressure to where your blow up pressure is is with in the percentages and stays stable for the duration of your trip.

An Example; My baseline pressure in my Steer Tires is 115psi and the blow up pressure stabilizes at 128psi. Drive Axle tires baseline pressure are105psi and the blow up pressure is 118psi. The tag axle tires baseline pressures are 95psi and blow up pressures are 107psi. these pressures are consistent whether I am on the road two or five hours.

As noted in prior posts about the inner drive axle tires having a higher pressure than the outer drive axle tires this is not uncommon, there is a lot of heat generated by the engine and transmission being funneled through that area. but a 30% jump above the base line pressure is and indication something else is going on.

When I was doing the tire pressure tests I saw that the inner drive axle tires blow up pressure would be 3-4psi higher than the outside tires. So I started to adjust the inner baseline pressure down until the inner tires would be at the same blowup pressure. My base line pressure on the drive axle tires are; L/Outer-105psi, L/Inner-103psi, R/Inner-102psi, R/Outer-105psi. One hour Blow up pressure is stable at 118psi.

All the tires on my coach are filled and maintained with Nitrogen.

My TPMS also measures heat. I very rarely pay any attention to it. Your tire psi will warn you of a problem with the tire long before the temperature will.

With the race cars the only time we are concerned with the tire temps is when we changed the tires in the pits. We would measure the temps across the tires along with the tread depth. The tires temps would tell us how the tire was contacting the track surface(GRIP) and if we need to make any alignment/suspension adjustments.

Dave - Great information.

On my coach as part of my pre and post trip checks, I typically take pictures of my custom TPMS screen at the start and end of each trip.  The line chart to the left is a graphic of tire pressures from the start of the trip.  On this trip it did take almost 2 hours of driving for tire pressures to stabilize but there was about an hour of low speed back roads before getting on the interstate.  One other observation I've seen is that rain will cool the tires and I'll see that on the line chart graph.

On this trip I'm seeing about +11 psi increase on the steer axle, +7 on the outer drive, +8 on the inner drive and +8 on the tag.  The toad was about +2 psi on all tires.  That's pretty typical for my coach unless outside temps are a lot hotter in which case all pressure on the coach go up about 4-5 PSI higher.

In case someone is wondering, the gray pressure reading on one of the toad tires means that there wasn't a received pressure reading within the last 5 minutes (I think pressure-pro sends out an alarm if readings are lost for over about 10-15 minutes).  Typically this gets resolved in the next few minutes and the block turns green.  Green means all pressures are OK - a red block would alert me to a problem and the pressure-pro display would send out an alarm.

[96 EVO]

What brand tires you running Frank?

I see a much higher psi increase with my Toyo's!

[Frank McElroy]

5 minutes ago, 96 EVO said:

What brand tires you running Frank?

I see a much higher psi increase with my Toyo's!

Was running Michelins but that was in May going from Ohio to NJ so outside temps would be cooler.  My typical rule of thumb is about +15 on steer, +10 on drive and +8 on tag.  But if it's really hot outside (high 90's), I've seen steer +20 and then I'll slow down.  Years ago, I used to run 65-70 mph - I'm now run 60-65.  Tires run a lot cooler and MPG went up!

[96 EVO]

I've never driven the coach in the hi 90's, but I've seen +20psi on the steers!

Recall reading on IRV years ago that Toyo's increase pressure a bit more than some other brands.

[Frank McElroy]

Here is another set of pictures from July.  Steer +15 PSI, PS drive outer +10, drive inner +11 (but on DS the inner was lower than the outer), tag +9 and toad about +3.  Pretty typical for me.

I just changed to Toyos.  Will be interesting to see what I now get for tire pressures.

[96 EVO]

3 minutes ago, Frank McElroy said:

 

I just changed to Toyos.  Will be interesting to see what I now get for tire pressures.

Yes. I for one will be interested to see if you notice a difference!

[Tom Cherry]

11 hours ago, 96 EVO said:

Yes. I for one will be interested to see if you notice a difference!

@96 EVO

EDITED to add more info and comment….

Go back to my post with my temperatures.  I THINK this was on a really hot day and I can also tell you pressures will increase around 2 PSI on asphalt versus concrete.

I am seeing up to a 13% or 15 PSI in the steers and 16-18 PSI (or %) in the rear.  Frank is running a few PSI higher of the steers, but with the tag, he can run about 10 PSI lower.  I typically run mine close to or at the plate data….remember I have a NON Tag.  Bottom line, I know that the Bridgestone ran lower (psi/%) than the factory GY. I don’t think that the Toyo’s are any higher….

As long as the ranges, and like David, I am a fanatic at watching the TP as I drive, don’t go crazy and are consistent and meet my …..hey….got on the brakes….and you can see the rise….I just monitor them. 

Ben, you may have the two ambient and bay  sensors.  I sort of check them.  I have noted on a long drive that there will be a 3 or more deg F increase on an interstate when you go from relatively new or clean white concrete to pure black asphalt.  As says, the ambient or reflected temperature does make a difference as well as in the early and late PM when the sun’s angle changes.  The outers and steer on one side will go up a few PSI and the front will be definitively higher on the sunny side.  Yes, I occasionally look at the road….  LOL.

I quit all my recording after I learned the characteristics of the Bridgestones.  Frank’s data screen is pure genius that he and the late “Hotrod” developed.  Taking a picture before and after for the files is great.

As an UPDATE to the original.  Here is a screen shot of the Tire INTERNAL calculation.  So a 20 PSI increase, rather the upper end 15 is getting close to a worry point (I chose 165 deg F).

This explains the relationship….

[Mocephus]

FINAL UPDATE - So, what caused the high temperature alarms on our inner drive axle tires…well that remains a mystery.

BUT the process of eliminating the possibilities has been pretty insightful and educational with Frank and Tom’s guidance.

Improper Tire Inflation? Nope, all pressures were acceptable with no cold pressure variances from one morning to the next and no major unacceptable pressure changes after a couple of hours on the road.

Taking the advice of Tom and Frank, today during our drive day, I asked my wife to record tire pressure and temperatures every hour. We did this so we could learn what is “normal” for our tires so that any significant variations in the future, will grab our attention. I’ll be crunching those numbers later to identify our “norm”.

Brakes dragging? Nope. The comprehensive air brake test that Frank and Tom provided, proved that the brakes were not the cause of the excess heat. Confession: I have a less comprehensive air brake test that I printed and laminated and placed in the pocket by the driver’s seat…and there it stayed but for once a year at the beginning of each camping season. If the brakes were dragging, I would not have known it and the potential damage could have been disastrous. 

Bad Bearings? Nope. Not likely since the inner tires on both ends of the drive axle dispatched temperature alarms. It would be a real long shot for both sets of bearings to fail at the same time.   Following Tom and Frank’s advice I purchased a laser thermometer and checked wheel temperatures during a fuel stop today. All good. Drive and tag temps were right at 125 F and the steers were right at 110 F. The rear end (aka “pumpkin”) was 202 F.

Overloaded drive axle? Nope but not perfect. A visit to the CAT scales showed the following:

Front - 14,100 (15,160 rating)

Drive - 23,140 (23,000 rating)

Tag - 6260 (10,000 rating)

After adding 5 PSI to the tag via the pressure regulator:

Front - 14,200

Drive - 21,860

Tag - 7,380

Still room for a little more tweaking of the tag pressure.

So, while the cause of the alarms is still a mystery it has been a great learning experience courtesy of our forum’s moderators. The depth of their knowledge and their scientific approach to sorting out issues is amazing.

 

Frank and Tom…thank you for helping me and thank you for all that you do to make this forum so valuable!

 

 

 

[Tom Cherry]

13 minutes ago, Mocephus said:

FINAL UPDATE - So, what caused the high temperature alarms on our inner drive axle tires…well that remains a mystery.

BUT the process of eliminating the possibilities has been pretty insightful and educational with Frank and Tom’s guidance.

Improper Tire Inflation? Nope, all pressures were acceptable with no cold pressure variances from one morning to the next and no major unacceptable pressure changes after a couple of hours on the road.

Taking the advice of Tom and Frank, today during our drive day, I asked my wife to record tire pressure and temperatures every hour. We did this so we could learn what is “normal” for our tires so that any significant variations in the future, will grab our attention. I’ll be crunching those numbers later to identify our “norm”.

Brakes dragging? Nope. The comprehensive air brake test that Frank and Tom provided, proved that the brakes were not the cause of the excess heat. Confession: I have a less comprehensive air brake test that I printed and laminated and placed in the pocket by the driver’s seat…and there it stayed but for once a year at the beginning of each camping season. If the brakes were dragging, I would not have known it and the potential damage could have been disastrous. 

Bad Bearings? Nope. Not likely since the inner tires on both ends of the drive axle dispatched temperature alarms. It would be a real long shot for both sets of bearings to fail at the same time.   Following Tom and Frank’s advice I purchased a laser thermometer and checked wheel temperatures during a fuel stop today. All good. Drive and tag temps were right at 125 F and the steers were right at 110 F. The rear end (aka “pumpkin”) was 202 F.

Overloaded drive axle? Nope but not perfect. A visit to the CAT scales showed the following:

Front - 14,100 (15,160 rating)

Drive - 23,140 (23,000 rating)

Tag - 6260 (10,000 rating)

After adding 5 PSI to the tag via the pressure regulator:

Front - 14,200

Drive - 21,860

Tag - 7,380

Still room for a little more tweaking of the tag pressure.

So, while the cause of the alarms is still a mystery it has been a great learning experience courtesy of our forum’s moderators. The depth of their knowledge and their scientific approach to sorting out issues is amazing.

 

Frank and Tom…thank you for helping me and thank you for all that you do to make this forum so valuable!

 

 

 

You are more than welcome…i get a lot of personal satisfaction from helping others, especially those that are wiling to do the hard work in the field….despite their concerns and apprehensions.  It is especially rewarding to help folks truly understand and learn.  They then become more resources for the group.

I also always learn a lot from a complex problem like yours as I depend on Frank to monitor and keep us focused.  He’s the real guru….and i just keep expanding my knowledge so i can help others and allow him to fix the “really tough ones”.

Safe Travels…

SURE GLAD it worked out and you will be a better MH owner and also have a safer rig…

[Ivylog]

On 6/11/2023 at 2:02 PM, 96 EVO said:

I wouldn’t add 5 psi to the tag. I liked these weight’s better:

 

Front - 14,100 (15,160 rating)

Drive - 23,140 (23,000 rating)

Tag - 6260 (10,000 rating)

[Mocephus]

2 hours ago, Ivylog said:

I wouldn’t add 5 psi to the tag. I liked these weight’s better:

 

 

Front - 14,100 (15,160 rating)

Drive - 23,140 (23,000 rating)

Tag - 6260 (10,000 rating)

Hi Dick, what are your thoughts about those weights?

[Tom Cherry]

2 hours ago, Ivylog said:

I wouldn’t add 5 psi to the tag. I liked these weight’s better:

 

 

Front - 14,100 (15,160 rating)

Drive - 23,140 (23,000 rating)

Tag - 6260 (10,000 rating)

Dick, no offense, but the DRIVE is over the limit. The advice that we gave Mo was to increase the Tag to the same ratio (% or percentage loaded) and get the axles balanced. He was loaded like this…

Steer is 93% of max.  Drive is 101% of max.  Tag is 63% of max.

Kicking up the load on the tag will shift  and balance them more.  He was then….

Steer 94%…. Drive 94% ….Tag 74%.

The dilemma was that going up 2 more PSI would add a smidge more to the front steer….but would or should have reduced the drive substantially. We discussed, off line, a minor tweak to add more weight…maybe closer to 9,000 pounds to the tag…but being cautious of getting way closer to 100% on the steer….a balancing act…. 

His issue is heat and stress or “running near max rating” on the drive.  An additional 100 pounds up front and knocking off 1,000 on the drive would probably lower the temps on the pumpkin or axle cover…radically or barely was the question….

He is also looking at the “gas law” calculator to see what the internal tire temps are.  That is the logic of balancing all your loads….we KNOW (ok…99% suspect) his excessive heat came from a max or smidge more overloaded rear axle…just don’t want to over react…as kicking up the weight on the tag DOES have an influence on the steers…the “wheel barrow” principle…

That’s our logic as well as following what Monaco says or intended to imply…

[dl_racing427]

I agree 100% with Tom.  Balancing the load with all axles under their limit is best.

I do something similar with the load bar adjustments on my equalizing hitch.

Edited June 17, 2023 by dl_racing427

[Jdw12345]

I realize this is a older post but this is the first time I’ve had a chance to do some testing.

 On our way to Wyoming, ripping our way across South Dakota, it’s hitting *90 and I’m running 65 mph for a steady 2 hours, pull into get fuel and did a tire temp reading with my laser temp gun, tires on the passenger side were 115-117, inner and outer were the same, tires on the driver’s side were 124-126 inner and outer were the same. I’ve never weighed my coach side to side but in my opinion the reason the drivers side was warmer was due to the wind blowing from the NW and the sun was on the drivers side, once again, jmo.

 I didn’t see any difference between the inner and outer tire temps on either side of the drive axle.

Edited July 22, 2023 by Jdw12345

[jacwjames]

42 minutes ago, Jdw12345 said:

I realize this is a older post but this is the first time I’ve had a chance to do some testing.

 On our way to Wyoming, ripping our way across South Dakota, it’s hitting *90 and I’m running 65 mph for a steady 2 hours, pull into get fuel and did a tire temp reading with my laser temp gun, tires on the passenger side were 115-117, inner and outer were the same, tires on the driver’s side were 124-126 inner and outer were the same. I’ve never weighed my coach side to side but in my opinion the reason the drivers side was warmer was due to the wind blowing from the NW and the sun was on the drivers side, once again, jmo.

 I didn’t see any difference between the inner and outer tire temps on either side of the drive axle.

Which side of the coach was the sun hitting.  My temps run higher on the sun side.

[Jdw12345]

Sorry, I should have made it more clear, yes, sun side was warmer.

[jimc99999]

My drive axle inner and outer usually run within a couple psi on the highway. On secondary roads in higher temps (e.g. the southeast summer) the inner tires trash 5-10 psi higher than the outers. I’m not sure whether it’s related to different loading with more turns, braking, road crowns, but it’s pretty consistent. 
 

Tread temps are usually 140F+  according to my infrared temp gauge, but road surface temps are 130F+ in direct sun. 

Edited July 23, 2023 by jimc99999