Axle weights

Most of the steer tires out there are rated for 12,500 lbs as a set. Most trucks are rated at 40K lbs, ie "40K rears" on the drives. If you look at a Rand McNally commercial drivers map book/atlas, they have all of the various weight ratings and king pin lengths that are legal for each state.

So in a nutshell, most trucks are structurally capable of carrying more than 12K on steers and 34K pounds on the drives and trailer tandems. So why are the legal weights low? My guess is that they don't want the roads beat to hell any more than they already are and they want the revenue from permits and fines.

 

I have been driving my 2000 Volvo 770 since I bought it in Sep 99, when they were really nose heavy. I was always over 12.5k on my steers when full of fuel and kept waiting for the tickets. People told me 'don't worry about it, the DOTs know the Volvos are nose heavy, you'll be ok. I gradually relaxed about it.

Even mounted APU under passenger door which put me at 12.9 to 13.2 or so, still no tickets. Sometimes suspected that I got Prepass red light because of it, but always cleared scale without incident.

I do run 16 ply tires, but if they ever looked at my axle rating, I'd have been in trouble.

 

You know about the allowable over on a axle if your gross is under a certain amount (late lol) that is good to go. Just a heads up

 

Wow, start with that and go on to give a bunch of misinformation.

The motor carriers’ road atlas is NOT a federal document. it is a private publication by Rand McNanlly and contains information from federal documents but has had misprints in some additions.

The weight limits listed in the atlas on the "National Weight and Size Provisions" page you seem to be referencing are only for the National Network (http://ops.fhwa.dot.gov/FREIGHT/infrastructure/national_network.htm) which consists of the Interstate highway system and designated Federal-aid primary highways. Other state highways and local roads are regulated by each state and those are shown in the atlas on the "State/Provincial Weight and Size Limits" page.

Nowhere I can find does it say they can only limit you by tire weight limits on the National Network. It contains a notation that says "States may limit the steering axle to the manufacture's weight rating if less than 20,000lb". This is talking about the steering axle rating, not the tire rating but the lesser of those two is what is enforced.

It also says“US states and Canadian provinces have the authority to adopt weight and size limits for some highways that may vary from those limits. Be sure to check the laws for those states and provinces in which you plan to drive“.

You can’t put tires rated for 10,000lb (20,000 total) on your steer axle and be OK for 20,000lb if your steer axle is only rated for 12,500lb. The axle rating is also considered and the lesser of the two is what you will be legal for on the National Network.

 

^^^2nd that. DOT did a crackdown here a few years ago. Lots of guys were running big rubber on a light duty steer axles. DOT said no matter how much the tires are rated for, the axle is the lighter of the 2 and therfore is the deciding factor. Just like in load securement. Weakest link determines the max load limit.

 

Umm... it would be best to just ignore this post in its entirety.

 

All states allow 20k per axle wether it's a streer tire or not fyi. Just 12k is the most common. Hell overweight permits you can do up to 25k or more per axle.

 

It's not dumb. It's rated weight at the factory that built the thing.

And yes you will be given a overweight citation for being over 34K on your drives.

Rated weights tell us that you can load it just so and it will be fine. As in safe.

Don't do what I did one fine day, decades ago put 137500 onto a 60's era mack. Just moving from the dock with the entire set of drives swaying side to side trying to break the lugs and fold or the axles flexing was not fun. But it did it. Probably totaled the thing because I never saw it again after that night.

 

Amen!!

 

Ive been driving for 18 years now and have had 2 overweight tickets. One when I got in a hurry to get home and slid the tandems in the wrong direction and one where I was loaded with wet cardboard with no scale between me and the nearest weigh station. You are welcome to your opinion but I stand by what I wrote.