Now he’s getting a Jeep and stinger

No, you really need the shim at the deck to level the trailer bogie. You can raise the neck some to do it but that’s not ideal. With a distributed load it’s possible but with a concentrated load you need yo shim.

 

Ok got it. Something super heavy would require more shims to even the axle weight out

 

Yeah kinda. You take something big that’s sitting on tracks it’s distributing the weight over the length of the tracks or an RT that’s blocked at the front and rear vs something setting in the middle like a crane or excavator without the tracks where the weight is concentrated you have to shim differently even though they may weigh the same.

 

On an east coast trailer you have to shim so that when you’re loaded your bogies are level. For this excavator before I loaded but after I shimmed with the air deflated the front trailer axle was off the ground. That’s 125,000 setting in 10 feet.
Here are the weights on the DOT’s portables.
I was pretty close with my shims. I could have pulled some spacers out of the gooseneck and that would have easily brought 6 and 7 more equal but it would transfer weight from 8/9 to 6/7 and lower the front of the trailer. I could also have pulled a 1/4” out of the deck shims which is difficult with a load on. If I pulled a shim on the booster it would have helped equalize 6/7 with 8/9 but I was fine on my permits. Had that been on tracks where the weight was distributed the shims would have been wrong. It’s as much art as science.

 

The guys that work with modular trailers have to carry lots of extra shims, one or the main reasons for different shimming on a same weight load is that a concentrated load will change the arch in the deck and therefore the shimpack will change to level the axle set while maintaining deck height.

 

Yep that’s what I just said, I’ve pulled a modular trailer most of career.

 

I see that a lot of the older west coast 2+2+2 set ups had air jeep and booster, but walking beam on the trailer. To a degree that would alleviate having to be so precise on shimming the deck wouldn't it?

 

Shimming the deck isn’t critical at all on a west coast for weight distribution because no matter what you put on the deck the weight ends up on the trunion between the bogies. The only reason I shimmed my west cost was to get ground clearance.

You should help jack a big load off of a 19 axle. It’s incredible how far they come up before the trailer is free.

 

6

Well, I feel kinda stupid now. I should have concluded on my own that the west coast design acts like a walking beam in and of itself.

Thanks

 

And I bow to you sir.
I was expanding on what you said to explain to someone who has not worked with a modular trailer and may not understand the concept. the first time I moved a load with a modular I had to stop and think about it before shimming to understand the why if it.
If i can make someone understand the why of shimming I may have made their first day of modular a bit easier. Of course there is so much witchcraft in our branch of trucking that they will still screw-up in any of a multitude of ways.