Having trouble figuring out the GVW for my new truck from the WSDOT website. I work in a rural area with no scales and never see "the man" otherwise I would ask him. It has 11R24.5's all the way around. The distance from center of axel to center of axel on the tandems is 4'6" and from the front drivers to the front axel is 15'6" giving a total distance of 20'0". Anyone out there have an opinion on this? Thanks!
It depends on the bridge law formula, try some trucking websites or google it. I know here in Illinois they change the laws more then they change politicians.
All you have to do is google, federal bridge formula and you get plenty of answers, but in answer to your question on any federally funded roads ie Interstate, your truck is good for 51,000. For the local roads you'll have to go to "the man" and ask them for a table or chart or booklet. http://ops.fhwa.dot.gov/freight/publications/brdg_frm_wghts/
Bridge for 20 foot wheelbase is 51,000 lbs Tandem can carry 34,000 You have 11 inch wide front tires at 600 lbs per inch, so 22 inches x 600 = 13,200. 34,000 + 13,200 = 47,200 lbs this is the legal weight you can carry since you are limited by the front tires and not the bridge. Here is link to Washington state commercial vehicle guide. http://www.wsdot.wa.gov/NR/rdonlyres/EE2D33C7-E6A0-4C58-9BD9-AE05C003B327/0/VehicleGuide.pdf Here is link to the bridge weight chart by itself. http://www.wsdot.wa.gov/NR/rdonlyres/46A25D5A-FE56-46BE-AEC6-47CB4BEC072D/0/Legal_Weight.pdf Also these laws, bridge, tire and axle weights are good for all public roads in the state. There is no difference if it is local, highway, etc. unless there is a sign posting a load/weight restriction. Don't know the weight of your truck, but I am estimating you can only carry 11-12 tons in the box legally. Which is 7.85 to 8.57 yards, not a lot. We have a Peterbilt with 11 inch front tires, but it has a lift axle so we can gross 55,500. Our Kenworth has 425 front tires so can legally carry 20,000 on the front axle, but we also have 2 lift axles so it can gross 60,500. Ways you can up your gross is to put on a lift axle or put larger tires up front. If you put on 365 or 385 tires you can get to the legal bridge of 51,000 and carry another 2 tons, but make sure you also change the axle it has to match or exceed the tire weight limit. With a lift axle you can carry another 4 tons.
Kgmz, Thanks for your input. Sounds like you got a real handle on it. Unfortunately, my front axel is only rated at 12k. From what your saying I can only have 34k for the tandems and 12k on the front which is only 46K. Is that right? I was hoping for at least 48K.... Do you know the most cost effective way add more gross? In other words, would it be easier and cheaper to add a new front axel or a drop axel? Do know on average what these costs might be? I think I am going to need some work done on the front-end anyway as my leaf springs are a little shifted and the steering is a little sloppy (if that makes any difference). Also, if I change the front axel do I have to let the DOT know? otherwise, If I get pulled over and the axel wt is different from the tag on the door are they going to believe me? Thanks for everyone's imput, Jon
First it doesn't really matter what the tag on the door says if the truck has been modified. DOT doesn't treat big trucks like they do with light trucks. But the axle better have a tag on it if it is modified. As for costs it depends on what you can get components for. To get to the legal bridge of 51,000 you would need to change the axle, springs, wheels and tires. If you go the lift axle route you would need the the lift axle, air kit for axle, and wheels and tires. And could then gross 55,500 With lift axles there are basically two types, a lift assembly that uses a standard 12,000 lb front axle, and the lightweight models that have a tube type axle integrated with the assembly. Then you just need some 10 x 20 tires and rims, you could save some money and get steel instead of aluminum rims. The best prices are usually around $3,800 for a lift assembly with a rebuilt front axle and around $4,900 and up for a lightweight. I usually buy this kind of stuff from Anderson Brothers in Portland, they also have distribution warehouse in Everett and Kent now. Looking at their ad in "My Little Salesman" they have a lift axle assembly with rebuilt axle or $3,795 and a Composite Lite ST for $4,795, both Hendrickson brand. I also see they have a rebuilt 18,000 front axle for $3,450 plus you would need springs, etc. So looking at these prices the lift axle is the way to go and the most bang for the buck. And the prices aren't going to be that much different, because those big 365 or 385 tires and wheels are not going to be cheap if you went the front axle route. Here is link to My Little Salesman Truck and Trailer February 2010 issue, and Anderson Brothers ad is on page 52. http://truckandtrailer.mylittlesalesman-digital.com/truckandtrailer/201002#pg1 Also if you want to look at different months issues, just change to year and month. When you go to the link look at the URL web address and you will see the number 201002, that is the year and month 2010 year and 02 month. The March issue is already out and if you change that last 2 to a 3 you will see the March issue. I didn't link it because there wasn't a Anderson Brothers ad in that issue.
Thanks again Kgmz. This is all very valuable info. The question is do I really want to put this kind of money into this old of a truck? I'll keep looking into it.....
I would put that kind of money into that truck, besides being able to haul more legally, you will get it back when you sale the truck, just something to consider.
Red Bank is right. Just compare prices out there for 3 axle and 4 axle trucks, you will get the money back down the road if you sell plus you will get more money now for each load you haul since you can carry more legally. Most people will expect at least a 10-12 yard load depending on the weight of your truck. By adding the cheaper lift axle you will add about 1400 lbs to the truck, but gain 8300 lbs in carrying capacity. So another 2.46 yards you can carry bringing you to 10.31 to 11.03 yards compared to my estimate in earlier post. Conversion is 1.4 tons to yard which is average for materials in this state.