Moving Tandem fro weight

Always push the tandems toward the heavier weight!

 

10-4 brothers truckers... ))) Yes I've found on page A16 - thank you - some notes referring to weight and size limits in different states... Not all but there are some and from what I see it looks like on average you can move 3' forward to make 38' cent. point and 2' back to 43' cent. point... Am I right ?

 

Some states do not have a limit. This is why they are not in there.
All the states that have legal limits will be on those pages.
You can basically move them forward as far as you like, it is when moving them back that you can get issues with the states.
Though it is a real pain to back a trailer with the tandems to far forward. You will have way to much swing.

 

I've always found it easier to back with a shorter wheel base on the trailer! The longer the trailer or tandems to the rear the harder you have to swing the tractor to move the rear. The over hang when the tandems are forward can be a pain but once you get backing figured out you can work the swingout to your advantage. I prefer a shorter WB on the trailer.
You don't work as hard with the tandems more forward.

 

There is a simple formula to determine how many holes to increase the trailer wheelbase.

Take the trailer tandem weight and subtract the drive tandem weight. Then divide by 500. The answer is how many holes to increase the trailer wheelbase. The weight will be evenly distributed between the trailer tandems and the drive tandems.

Now if the answer is a negative number [the drives are heavier than the trailer tandems] shorten the trailer wheelbase that number of holes.

If you are going to slide the tandems anyway, try it for yourself and see if you notice the difference.

 

Doesn't it depend on the spacing between holes?...I've seen differences...We were taught, as a rule of thumb, 1'=850lbs, is that a fair guestimate to use?

 

If the holes are about 2-3 inches apart, then moving one hole will move APPROXIMATELY 250 pounds. In the above formula, you divide by twice the amount that each hole moves.

For example: if each hole moves approximately 250 pounds then divide by 500. If each hole moves approximately 500 pounds then divide by 1000.

 

depends more on how the trailer is loaded !!!!

 

There is NO set formular for deciding what weight is moved for each hole.
There are several things that will change this "formular" of 500 pounds!
Weight of freight, how long the load is or how many pallets . Is it all one product or a mix of different products each weighing a different weight.

The distance between holes on the rail really does not matter.

The ONLY way to tell what each holes "change of weight" figure is will be to use "rough math when you need to slide the trailer.

First you have that scale ticket in hand and you see that you're say 1234 pounds over on the tandems so you do the math at that 500 pound number thrown out there earlier. You come out with 2.468 holes so you slide the thing 3 holes and wow! You're now say, instead of the target weight of 34,000 youre at 757 pounds less or 33,243 and you wonder WHY? It turns out that the weight was 350 pounds per hole!

The only thing you can do is gestimate everytime you slide the tandems! THEN after the first slide you do the math per each hole you slid and you can refigure the weight and sldie and forget the extra dollar or go ahead and be pretty much where you want to be on weight!

If you pull the same freight from the same place you'll pretty much figure where to pre set the tandems OR know what the weight per hole is.

There are a few different trailer manfacaturers and they are all different. Yes some have 3" hole distances and some 4" but due to the differences of how the trailer was build and if it a dry or reefer and the manfacature has a plate that says each hole is so and so pounds per hole just guesstimate and go from there!

I finally got to where the 350 pound figure worked better than the 500 pound did.

When loaded look at the BOL for their perceived weight. You'll be surprised how many companies have no freaking idea as to what their product weighs! If you have that weight gauge on the dash and you've gotten it figured out to where the needle is at 34,000 you can guess where and what weights are and how far to slide. Now I have to admit I've got 32 years at this and can almost look and slide before I waste money on a scale but still, Look at the BOL. Look at where the load comes to in the trailer, look at the tires and look at the gauge and then count holes and make a decision.

That $9 scale ticket will save you a lot of headaches!

 

4" on center holes = 250lbs per hole
6" on center holes = 400lbs per hole
Fifth Wheel = 500lbs per hole