Converting a class 8 3 axle to a straight truck

terminus · Jun 25, 2004

Hey All,

I've been lurking your site and have some questions I haven't seen yet. Currently I have 5 class 8 tractors and run under my own authority. I've been thinking about converting one of them to a straight truck. Why? I have customers that give me freight that's only 8-12 pallets and under 12k lbs. These I should be able to do, easily, in a straight truck.

I've pretty much decided to leave the thrid axle in place and obtain a 26' box. The truck I plan on using is an FLD112, which is a very light class 8 truck.(16.9k w/fuel and a 48" condo).

My questions are:
1. What wheelbase would I need to axle out to max wgt? I figure I could gross 52.5k (20+20+12.5) so that leaves about 35 or so for the box and freight.
2. How much do boxes usually weigh?
3. Swing or roll up doors?
4. Has anyone here gone through this process, and what sre the pitfalls, if any?

Please, by all means, offer any advice you might have.

Thanks
Wesley

Glen Rice · Jun 25, 2004

RE: Converting a class 8 3 axle to a straight truc

Hey good question! Try centering the tandem on your box. Or better yet get with your dealer and run a water weight calculation with the setback of your front axle, fuel tank capacity, driver and co-driver weights, liftgate, and personal belongings including equipment you may be carrying. The wheelbase could be anywhere based on these findings. You need to know the numbers [lbs] and plug them into the formula. Again, quessing at it would put you somewhere in the middle of the freight box. Take the time and run it by your dealers program. They will give you a closer number than just quessing at it.

silverdollar · Jun 26, 2004

RE: Converting a class 8 3 axle to a straight truc

You might also want to think about overall length,about all states limet straight trucks to 40ft.

Doggie Daddy · Jun 26, 2004

RE: Converting a class 8 3 axle to a straight truc

terminus, i am pretty sure that you are wrong about the total GVW of this setup. while the rating of the rear axles may be 2x #20,000 ithink you will find that a majority of states will restict you to #34,000 on the tandems. it's possible that i could be wrong, it's happened before. DD

terminus · Jun 27, 2004

RE: Converting a class 8 3 axle to a straight truc

You are absolutly right. I don't know how I overlooked that!

I have been using 34k in all of my calcs, thanks for pointing it out.

Wesley

terminus · Jun 27, 2004

RE: Converting a class 8 3 axle to a straight truc

Glen: I was thinking about centering, but got confused! Uh, where was I...oh, yeah...centering over axles. My thoughts were...if I did center the box, wouldn't that naturally dictate the length of it? No, it would only center it. The length should be dicated by the max overall length, weight distribution and, wheelbase. Does that sound right to you?

Wesley

X1_SRH · Jul 8, 2004

RE: Converting a class 8 3 axle to a straight truc

About the doors.... I have always loved roll-up doors just for the convenience factor, but they are historically prone to falling apart after a few years. Knowing what I know now, I would definitely go with barn doors and avoid future headaches. This is just based on my own experience.(for what it's worth...).

davekc · Jul 8, 2004

RE: Converting a class 8 3 axle to a straight truc

Barn doors were great until the wife decided she didn't like getting out in the rainy or cold weather, so we went to a roll up door. Ours has held up pretty well. Only item that required repair was the replacement of the cables. Seem to last only a few years. Other than that, they are great, plus you can open and close your door right on the dock.

bluebird · Jul 9, 2004

RE: Converting a class 8 3 axle to a straight truc

making a class 8 into a straight truck is the way to go. the bigger engines get more miles then those smaller ones with out alot of more miles to the gallon. just my two cents lol

davekc · Jul 10, 2004

RE: Converting a class 8 3 axle to a straight truc

I would agree that a class 8 should get a longer life span, however if a class 7 is speced right it will achieve simular or better milage. We have a class 7 and it is in the 10 to 12 mpg range. I am not aware of any class 8's doing better than that. Certainly not any of the ones we have had in the past.