Freightliner M-2 112

HoosierHllyBlly

Seasoned Expediter
I have a 06 M-2 112 Freightliner with a 94 condo sleeper and 22 ft box. This is a white glove unit on with Fedex. Truck was put together by Alumi Bunk. Truck has a 300 inch wheel base with tag axle. TRuck also has the MBE 4000 engine. Here is my problem I have to much weight empty on the steer and cant take any off when i use my tag axle. The tag hurts me more than helping me. Right now the most I can care is 5000#. Does anyone else out there have this problem or anyone know of a fix solution to my problem.. Looking for any suggestions here.

Thanks and Be Safe
HoosierHllyBlly
 

NEVERHOME247

Veteran Expediter
Charter Member
Just a suggestion. Might want to move the tag and make it a pusher. It will take the weight off the steer. When you have it down.
 

HoosierHllyBlly

Seasoned Expediter
Rowe Truck out of Otterbein In installed the tag..I think it does need the push axle instead of the tag. They are talking about moveing the drive axle up and the tag too. But I dont see how this will help.

Thanks for your imput
HoosierHllyBlly
 

ATeam

Senior Member
Retired Expediter
In general, the shorter the wheelbase, the less weight the front axle will have to carry. Wheelbase is usually expressed in inches. It is the distance from the center point of the front axle to the center point of the rear axle. In the case of tandem axles, it is the distance from the center point of the front axle to the center point between the tandem axles.

Regarding weight distribution, envision a playground teter totter with two kids of equal weight on each end and the pivot point at the center. The teter totter will sit level unless the kids get it moving. If you move the pivot point to the left, the kid on the right will "out weigh" the kid on the left, though each kid's actual weight stays the same. The weight distribution of the entire assembly (the kids, the board, and the pivot point) changes such that the kid on the left becomes "lighter" than the kid on the right.

So too with a rear axle. Imagine viewing the driver's side of a straight truck with the front of the truck pointing left and the rear pointing right. Moving the rear axle forward shifts the weight of the entire truck off the front axle and onto the rear axle. In the case of tandem axles or a deployed lift axle (tag or pusher), moving the axles' center point (sometimes called the "bogey") forward reduces the weight carried by the front axle.

On a straight truck, dropping a tag axle (lift axle behind the drive axle) increases the wheelbase. When the lift axle is on the ground, a bogey is created that did not exist when the lift axle was in the air. The bogey is behind the drive axle, which increases the wheelbase. Dropping a pusher axle (lift axle in front of the drive axle) decreases the wheelbase by creating a bogey forward of the drive axle. Most expediter trucks that use lift axles use pusher axles because shortening the wheelbase reduces the load on the front axle.

Some 53-foot trailers have adjustable rear axles. At truck stops, and especially around scales, you can sometimes see tractor/trailer drivers repositioning their trailer axles to achieve legal axle weights on a heavy load. As one driver once told me, "Move the axle toward the problem."

You can experiment with this in your own truck to better grasp the concept. Next time you get a load of say 5,000 pounds or so, and if the freight is compact enough, position the freight such that most or all of it is behind the drive axle. Then go to a scale and weigh your front and rear axles with the lift axle up. Then weigh the truck three more times, each time with the lift axle down, once with a light lift-axle pressure setting, once medium, and once heavy. Write the pressure settings on the corresponding scale tickets and review your results. Compare the results to your truck's weight when empty. If possible, weigh the truck empty at the same scale you will weigh it loaded. Using the same scale for all readings will give you the most accurate results.
 

davekc

Senior Moderator
Staff member
Fleet Owner
Rowe Truck out of Otterbein In installed the tag..I think it does need the push axle instead of the tag. They are talking about moveing the drive axle up and the tag too. But I dont see how this will help
=====================================================
If you are running smaller loads, put more weight towards the back. In many cases, that may not be an option, especially if you don't know exactly what you are picking up and just know the weight. Many times a customer will add something at the last minute, and you could potentially lose your load.
If a load takes up most of your floor space, and or is unstackable, you may not have the option to move the weight around to compensate for the front axle weight.
You would be better suited to run a pusher because you can control the freight end weight. Just adding 30 lbs of pressure into the axle can change the front end weight considerably with a average 4000lb load. Tags are cheaper and easier to install, but it seems the pusher would suit your needs better.




Davekc
owner
21 years
PantherII
EO moderator
 

DocRushing

Expert Expediter
Here's a copy of a discussion on this subject which I contributed in December 2004:

This principle is very useful in loading a truck:

If the driver loads the cargo in such a way that the center of mass (center of gravity) is directly above the drive axle (or halfway between the tandem drive axles), then the entire weight of the cargo bears directly onto the drive axle(s).

If the driver loads the cargo in such a way that the center of mass is somewhere forward of the drive axle(s), then some of the weight bears onto the steering axle, and less of the weight bears onto the drive axle(s).

The farther the center of mass of the cargo is forward of the drive axle(s), then the more of the weight bears onto the steering axle.

Conversely, if the driver loads the cargo in such a way that the
center of mass is behind the drive axle(s), then all of the weight of the cargo bears onto the drive axle(s) -- and some of the weight on the steering axle shifts onto the drive axle(s)!

The farther the center of mass of the cargo behind the drive axle(s), the more of the weight on the steering axle shifts onto the drive axle(s).

How much weight goes on or comes off the steering axle?

That's easy -- with a simple calculation:

If the center of mass of the cargo is 5 feet forward of the drive
axle(s) or behind the drive axle(s), and if the wheelbase is 25 feet, then 5/25 of the weight moves.
5/25 = 1/5 = 0.20 = 20%.

In this same example, if the cargo weighs 5,000 pounds, then 1,000 pounds (1/5 of 5,000 pounds) shifts onto the steering axle or off it -- depending on whether the center of mass of the cargo is 5 feet forward of the drive axle(s) or 5 feet behind the drive axle(s).

If the center of mass of the cargo is 5 feet forward of the drive axle(s), then 1,000 pounds of the cargo bears onto the steering axle, and 4,000 pounds bears onto the drive axle(s).

In the other direction, if the center of mass of the cargo is 5 feet behind the drive axle(s), then all 5,000 pounds comes to bear on the drive axle(s) -- AND 1,000 pounds come off the steering axle and shift onto the drive axle(s), so that 6,000 pounds altogether come to bear onto the drive axle(s).

To picture this, imagine a seesaw on a playground.

Imagine what happens -- imagine the action of the seesaw -- as two or more children take different positions on the seesaw.

Now imagine that your truck is a seesaw with its fulcrum at the drive axle(s).

Then imagine what happens as your cargo occupies different positions -- fore and aft -- inside your cargo box.

This is not empty speculation; it really works.

Note this well:

If a driver wishes to avoid adding more weight to the steering axle, load the cargo in such a way that the center of mass of the cargo is nowhere forward of the drive axle(s) -- either directly above the drive axle(s) or behind the drive axle(s).

How can we determine where the center of mass is?

A careful eyeball estimate often works fairly well.

Maybe we could even measure the cargo.

Try this sometime!

By the way, this principle is one very good reason to avoid loading cargo all the way into the nose of the cargo box unless necessary.

Many loaders tend to shove the cargo all the way into the nose -- even if the cargo is rather small.

Many drivers also tend to do so.

By controlling the position of the cargo, we can control not only the loading of the axles but also the quality of the ride and the handling of the truck.

As always, best wishes to all,

Doc.

PS. For those who dislike math and physics, please feel free to disregard this whole thing.
 

RichM

Veteran Expediter
Charter Member
Steer tires will also last longer if you follow Doc's advice,but make sure you secure that cargo so it cannot come forward in the event of a sudden stop.
 

DocRushing

Expert Expediter
Amen on the securement!
I use -- depending on the size and shape of the cargo -- usually at least two or three shoring beams at the forward end of the cargo -- plus usually at least two straps on the after end of the cargo.
Proper securement is an indispensable part of avoiding cargo claims.
Doc.
 

simon says

Veteran Expediter
Charter Member
The only way this will ever work right is, unfortunately, to bite the bullet and pay to install the pusher. You may also have to move the rear axle, probably forward, as well. Do not move the rear forward and leave the lift axle as a tag. A-team is correct, but here is a precise way to guage what must be done.

1) Get a tare (empty) weight of the vehicle as it is now. You want to know what the front and rear weight is. One scale weight is close enough, at any reputable scale. Any vendor that has a scale as you leave will tell you also, if you ask.

2) Here is a formula I learned a long time ago, when I learned how to spec trucks before the advent of computer programs at dealerships. Any good older truck salesman can tell you this...
Bear with me! First some terms you need to know involving dimensions. Get a decent tape measure.
FA: distance from front of truck bumper to front axle(38inches?)
BBC: distance from front of truck to front of box (203 in.?)
CA: distance from front of box to Rear axle (in your case,
probably only 135 in.)
WB: wheelbase (300 in.)
WL: Water level load- consider your box as a vessel holding water. Let's call this the distance that payload is loaded in the box. I use 20 ft, 240 inches. YOU WILL NEED 1/2 OF THIS TO COMPUTE; 120 inches.
Payload: maximum weight you can carry. Use single axle for now.
WF: weight on front axle loaded, (truck fully loaded.) This is a percent.

Here is the formula to compute how much the front steer will weigh with a load on. Two part formula...

WF = CA - 1/2 of WL / (divided by) WB (stay with me...)

Let's say your truck weighs 11,800 empty on the Front. Let's say your total weight is 23,000 fueled up with you in it. Tag up, you can only carry theoretically 9,000 lbs. (32 GVW)
CA 1/2 of WL WB
WF= 135 - 120= 15 divided by 300 = .05 (5%)

Now:: Percent x load you want to carry: .05 x 9000= 450lbs
Total weight on front axle is 12,250 lbs. You are not too bad.

You must distribute that 9000 up to 20 ft. If you load those heavy 5 skids (1800 each) in 12 ft of truck, you will be way overweight on the nose, about 13,500 lbs and you are O.O.S. at Jellico!

To figure weight with tag, use midpoint between the two axles. Everything above becomes much worse. No wonder you cannot carry any weight, unless you ##### load everything!
Sorry for the longwinded piece, no way to explain otherwise. Have trouble, send me a private note, and I'll figure it out for you
 

simon says

Veteran Expediter
Charter Member
OOPS I used a bad word. Meant no wonder you have to rear load everything! I assumed you have a 12,000 lb. steer axle. I drove a FL 106 with a Detroit series 50 for about 6 weeks. It had a pusher and 300" WB and only a 72" Bentz on it. I immediately found that it was very front heavy. I looked and found the tare weight slip, and it weighed 11,400 on the front, 22,700 total. I had to carry anything heavier than 5000 lbs. to the rear, using up at least 16ft. of the box. Anything over 5000, and I had to drop the pusher across the scales. I also used the pusher for wind and nasty snow-ice once. Heaviest load carried was 14,000 lbs. and used all the 22 ft to distribute it- leaving first 4 ft. empty.
I would configure your truck to haul maximum GVW weight of (is it 46000?) or payload of 21,000 lbs. with the PUSHER down. Then you can figure out what you can do with pusher up- max. payload. YOU may be o.k. with Rear axle where it is. I hope so- if you have to move it front or back, you better get Alumijunk to put it in writing that they wiil eat it. Moving a drive axle costs about $1000. x(
 

wallytrucker1

Expert Expediter
You may be able to increase the load bearing weight on your steer tires by going with a larger ply ( 16 ply ) and this should take your steer axle capacity( spelling ) to about 13000# I THINK....Help me out guys am I right or not.
 

HoosierHllyBlly

Seasoned Expediter
Just wanted to thank everyone for there input..think were going to change it to a pusher.

Be safe out there everyone
HoosierHllyBlly:D :D
 

Peace2All

Expert Expediter
Is tag axle mounted in front or behind the drives? Same princple as sliding tandems under the weight on a big rig. What is the weight on the front end? What gallon capacity are your tanks? Can you alleviate any cabinets and mount them in the rear of the cab? Are you weighing when your fuel tanks are full? Do you have a double bunk that is not needed?

If you fueled and then weighed, bad move. Do you have a water holding tank? Was it full? Just some things to ponder.
 

simon says

Veteran Expediter
Charter Member
Technically yes, without looking it up, may be more than 13000. I know Sterling and perhaps others, market spring capacity to 13,200 at least for a 12K axle for extra protection. But: still any truck is rated at lowest common denominator for each axle. Even with springs at 13200, or tires at 14000, you cannot exceed an axle rated at 12000: going over scales that is...
 

HoosierHllyBlly

Seasoned Expediter
Peace2all,

Tag is behind the drive. And empty weight on steer with full tanks ( 2 80 gallon tanks ) is 11,760.We also needed the top bunk since there is a team running it. I think moveing the tag to a push axle would be our best bet. But were still open for suggestions here.

Thanks for your imput
HoosierHllyBlly
 

ratwell71

Veteran Expediter
Hummmm, is the cost associated w/ making it a push axle worth it? Maybe you should just register the vehicle for what it can haul. We did and have never had any problems. It is actually cost effective, and you will get better fuel economy.

Your engine will love you too!

Have you called around to different shops to get an expert opinion. Sounds like you want to be able to use the hp of the engine, but it has been my experience that unless the load pays well to cover the amount of fuel, oil, and rubber that is being used it isn't worth hauling. I have never hauled more than 6,000 pounds in my truck and to haul that was unusual in this line of business. The majority of my loads weigh under 3,000 pounds and I like it that way.
 

Florida

Expert Expediter
:'(
The most you can tare out is 5000 pounds?? For a 22 footer?
Tells me that you are carrying around too much truck, sucking up diesel in the process.

Compare that to a regular Budget or Ryder 24' box truck (no reefer and no liftgate). That truck can load 12,000lbs or cargo for 26K GVW.

The major problem is focused on those sleepers. Dead weight far as I am concerned. Unless you like a quick snooze behind the cab of an idling diesel motor, use a cheap motel. $39.95 per day, and tax deductible, and has toilet facilities and food.

Those sleepers are dead weight. Dead weight costing you money in terms or payload capacity.

5000 pounds? I can almost carry that in a little 15' Isuzu NPR van which has those little 4 cyl turbo diesel motors. Not exactly dock height, but ECONOMY.

Those sleepers are only really useful in situations of TEAM runs where the truck practically NEVER stops. For a single driver situation, nah. Extra weight, costing you money to buy it, and tow it around America.

Depending on where you run the most, match your engine horsepower to the GVW of the vehicle and gear it to get the motor to operate in the "sweet range" of max economy. Nobody needs 50,000 horsepower motors. For a small box truck, 300 should be fine for 26K GVW.

Unless you climb mountains all day, you really don't need that fuel guzzling HP, or that sleeper.

Costs are high enough as it is, and rates are pathetic as they always have been - no sense in tossing out cash needlessly.

"Match the vehicle to the load" Be practicle, and drive sensible.
Stay out of Rush Hour situations - park it and wait, or pay for a bypass toll road.

30 years in the trucking business has taught me a few tricks.
One of those is watch out for those little old cow towns which drop the speed limit down to 25 or 35mph for a short stretch of raod, usually 1000 ft or less. That reads: SPEED TRAP.
 
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