Covert a class 8 tractor to straight truck

guido4475

Not a Member
What are the pro and cons of coverting a class 8 tractor to a straight truck??

There are so many opions on this as to what is better.I actually think it should be what is better for the application and drivers needs.

I have always had single-axle straight trucks(T-300, FL-70,4900,etc) And did just fine with those single axles.I went and bought a class 8 tractor stretched and it was the biggest waste of my money.Here is why:

In the 4 years I have owned it,Only 6 loads warranted that extra axle in the back.(it was a tandem).So imagine the cost of higher rated license plates,tolls, extra set of tires and brakes,loss of fuel economy,etc all over 6 loads in 4 years.It did not even pay for itself, but cost me.The only reason that the tandem axle helped me was in the terms of empty weight.It was an extremely heavy truck,At 29,000 # empty weight, full of fuel.(400 gal cap).So I needed that extra axle to be able to haul any amount of respectable weight.

The only way I would do a class 8 straight stretched tractor is if it were a single axle.With a smaller Cummins or Detroit in it, around 350 hp, with an autoshift, and gears in the back that will let it run 65-70 right in the engines sweet spot.Too many people buy the wrong spec'd truck for their application and wonder why they are maxed out at 2,500 rpm running 60 mph, getting 8 mpg.Yes, I think a class 8 will outlast a class 7 anyday,but it comes with higher parts and maintenance, in most cases.I do have freind that has over 1.5 million on his Ford L-8000 and still looks and runs new with the 5.9 cummins and allison automatic in it.In a nutshell, it depends on how you take care of a vehicle as to how long it will last faithfully.Kinda sounds like marriage !!
 

x06col

Veteran Expediter
Charter Member
Retired Expediter
US Army
I've stretched some. They can be a good thing if you avoid some rookie mistakes. Find an exceptional frame shop, stay away from large engines and more than a 10 speed, don't start with a truck that will finnish too heavy, don't try to convert a 28 ft semi pup for a cargo body.
 

moose

Veteran Expediter
Call your carrier of choice , and ask them if they have a use for this truck , & if so , for what payload .
then take phone #'s of a few contractors already leased on to that carrier with such a truck , and ask them how they will outfit their next truck to better serve the carrier needs .

the Freightliner Dealership in Rochester M.N , is stretching trucks weekly & have many repeating costumers over the years.

O'h Yah ...
400 GAL. !! ???
on a truck that gets ...what ? ...10MPG ???
 

bluejaybee

Veteran Expediter
I have never had a tractor stretched, but have had a straight truck stretched to make a cattle truck years ago. I have driven two others that belonged to other people that had been stretched. Mine was done by an outfit in Nashville and came out an OK truck. It drove good and ran the road straight. The other people had a small repair shop do their's and it ran down the road sideways and kept the tires wore off. Plus, one of them had an incurable whine in the drive train. So my thought is this. If you gonna do it, make sure you get someone who knows how and will stand behind their work.
 

geo

Veteran Expediter
Charter Member
Retired Expediter
US Navy
why do it that way when you can order the truck from dealer and get it from start

when i had my western star order it from the dealer with it fit 16' box
 

Andrew0580

Seasoned Expediter
I have a 2002 FL century twin screw, N14 cummins, 10 spd autoshift. it weighs 24000 with 200 gallons of fuel, 2 drivers, and a tripak hangin on the side. I LOVE this truck! It leaks nothing, it burns 1/2 gallon of oil in 15000 miles, gets an average of 9.12 mpg ( I have gotten as much as 10.46 ) and gives me NO trouble. I also own a class 7 that I would make more money if I just opened a repair shop and paid myself to work on it! As far as a twin screw goes I would agree that it is not needed, but due to the extra weight of a class 8 I would at least get a drop axle, because even though you can register the single axle at 33,000 most states only allow 12,000 on the front and 20,000 on a single rear axle.
 

guido4475

Not a Member
To answer the fuel capacity question: It was a Sterling Silver Star and it was a tractor that, yes, had 2-200 gallon tanks on it.With the way I used to run renegade,that was a blessing as I could run almost coast to coast without fueling,which helped me make the logbook work to accomodate non-stop runs like this.It got around 7.5 mpg with the c-15 550 hp engine, 10 speed trans.Not the most fuel efficient, but it sure would get the job done fast, NEVER drop out of 10 th in the moutains,and it would move weight like it wasnt there.

As far as the front axle weight was concerned, the empty, full of fuel weight of this truck on the steers was 14,200#.I put new springs, added a leaf, which gave me an 18,000# front suspension on it, and upgraded the front tires to 16-ply, which have a better weight carrying capacity than the standard 14-ply that most use.The next step up from that would of been a 12-inch wide tire, which requires a rim 1" wider than a standard, which is also known and used mainly by bus/coach manufactureres such as Prevost.I have only had 1 incident where I was given a hard time with the weight on the front, and that was in Oregon.The DOT Guy there was cool, and ended up with a warning ticket, and a nice freindship that we talk to once in awile.I was on a secondary highway which has different weight limits than that of a regular highway.Check your road atlas, and look at the axle weight and capacity page located towards the front, and it would surprise you how many states allow over 12k on the front axle.I ran it for 4 years this way, and believe me, if there was a problem, they woulld of got me on it.
 

Tennesseahawk

Veteran Expediter
Pros:
- Nicer ride
- More allowable weight = higher rate, IF you get with a company that'll utilize your truck when they can.
- More power
- Doesn't cost more to tag than a 2 axle, in most states
- Last longer with decent care, than a class-7

Cons:
- 4 extra tires
- Watch your front end weight.

Unless you had a newer tractor to stretch, I would buy one already built. They are low priced right now. You could start out with a 2000-01 model for around $15k, and still should be able to get a few years out of it.
 

Andrew0580

Seasoned Expediter
To answer the fuel capacity question: It was a Sterling Silver Star and it was a tractor that, yes, had 2-200 gallon tanks on it.With the way I used to run renegade,that was a blessing as I could run almost coast to coast without fueling,which helped me make the logbook work to accomodate non-stop runs like this.It got around 7.5 mpg with the c-15 550 hp engine, 10 speed trans.Not the most fuel efficient, but it sure would get the job done fast, NEVER drop out of 10 th in the moutains,and it would move weight like it wasnt there.

As far as the front axle weight was concerned, the empty, full of fuel weight of this truck on the steers was 14,200#.I put new springs, added a leaf, which gave me an 18,000# front suspension on it, and upgraded the front tires to 16-ply, which have a better weight carrying capacity than the standard 14-ply that most use.The next step up from that would of been a 12-inch wide tire, which requires a rim 1" wider than a standard, which is also known and used mainly by bus/coach manufactureres such as Prevost.I have only had 1 incident where I was given a hard time with the weight on the front, and that was in Oregon.The DOT Guy there was cool, and ended up with a warning ticket, and a nice freindship that we talk to once in awile.I was on a secondary highway which has different weight limits than that of a regular highway.Check your road atlas, and look at the axle weight and capacity page located towards the front, and it would surprise you how many states allow over 12k on the front axle.I ran it for 4 years this way, and believe me, if there was a problem, they woulld of got me on it.

I can relate with the DOT, somewhere on my truck is a sign that reads " Please pull me in and inspect me" and I have not been able to locate it so I can take it off! 550HP sure would get it done in a hurry! LOL even my 400HP is too much you can set the cruise and it too never slows down. I think like you said before 350 is ideal anything more than that is overkill. I once saw a KW W900 600 cummins and an 18 speed with a 22' box now that is crazy!
 

guido4475

Not a Member
I can relate with the DOT, somewhere on my truck is a sign that reads " Please pull me in and inspect me" and I have not been able to locate it so I can take it off! 550HP sure would get it done in a hurry! LOL even my 400HP is too much you can set the cruise and it too never slows down. I think like you said before 350 is ideal anything more than that is overkill. I once saw a KW W900 600 cummins and an 18 speed with a 22' box now that is crazy!

The K-W W-900 with the 600 Cummins and the 18-speed. I saw that truck at Freightliner of Knoxville.It was a beautiful truck, well equipped with the finest options, Willis generator, liftgate, etc.I seriously considered that truck, but 2 things killed that idea really quick.The 18-speed stick, and the salesman.Treated me like ****,If he only knew what he didnt.Now I see he's a recruiter for Celadon.Go figure.
 

greg334

Veteran Expediter
guido,
I am confused.

You are 14.2k on the axle, put another leaf in and now 18k?

What about the axle, you swap out the axle?

Putting another leaf in means really nothing if the axle is rated at 14k, right?
 

guido4475

Not a Member
I feel honored that I confused you-LOL.

For some unknown reason, the truck was setup with 44k rears, and a 20k front, even though the alignment shop (a very reputable shop right in your neighborhood)said the front taperleaf spring setup was rated for only 12k, according to the Ford dealer,(Bi-State).We dont know why this was the way it was, or why the truck was spec'd so heavy to begin with, even though it was just an otr tractor.Everything was spec'd heavier than normal,according to my freind at Ford once I gave him the vin and he looked at how it was setup.
 

guido4475

Not a Member
I don't remember if it said excactly that or not, but I do remmeber the Ford dealer telling me that.Why, is this something that is difficult for you to believe?
 

jaminjim

Veteran Expediter
The W900 you are talking about was Leo's. (LBD) It was/is the finest looking expediter trucks to hit the highway ever. The main problem with that truck was the fact that it was about a foot and a half to long in the wheelbase.(To heavy on the steers) and the eighteen speed. other then that it was outstanding.
 

greg334

Veteran Expediter
No not really Guido but the guy doing the level 1 may look at your sticker and wonder about it too. It's the sticker that seems to rule.
 
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