Class 8 truck conversions

[DKinWA]

Hi guys,

I'm looking for pros and cons of converting a class 8 highway truck to a dump truck. There are a lot of reasonably priced trucks out there that still have a lot of life in them. I've been looking primarily at trucks without sleepers since the conversion would be that much easier without them. I'm also wondering about the air bag suspensions vs spring suspensions for dump truck type work. Many of them also already have wet kits making the conversion even easier.

Most of work is around residential sites and involves foundation excavation, septic systems, driveway improvements, etc.

If nothing else, this should provide for some lively discussion

Thanks

 

[2004F550]

I don't know about these trucks, I've heard mixed reviews about them. Road tractors are built differently then a Construction/site truck. For one is the gearing, these trucks will most likely have high gearing made for over the road travel which is not good for off road work where you want slow steady speed. Another thing is the transmission, most of these trucks will have a transmisson geared towards over the road travel, ..ex. a 9 speed w/o a low range. You really want something along the lines of a 13 speed or maybe even a 18 speed for really rough work.

If the truck was going to haul asphalt from plant to paver over the highway these ex-tractors would be perfect,but for off road i think you would be better off w/ a real dump truck.

In interms of the suspension you would rather have something like a Chalmers Rubber block suspension for off road work or spring bundles, air bags and off roading could equal big problems if the ground is rough. In the worst cases it can lead to tip over especially if the operator is inexperienced w/ air bag trucks. The air bags shine in highway trucking w/ high speeds.

Anyway this is all JMO..hope it helps some:drinkup

 

[Steve Frazier]

I don't claim to be an authority on setting trucks up for construction, but I drove trucks both on and off road for 25 years. I think an inter-city hauler might be better matched to construction work than an over the road truck. I agree with the gearing, most over the road trucks have higher gears for better fuel economy in their hauling. This would sacrifice off road performance. You could always change the rear end gear, but on a ten wheeler you'd have to do it twice.

On the suspension for a ten wheeler, look for a Hendrickson walking beam suspension, stay away from Reyco, they tend to get hung up on uneven terrain. In the past 5 years, I've seen air suspension used on purpose built dump trucks, but I've never run one. You'll want a Power Divider too, kind of like a posi unit for tandems if that's what you are looking at.

I'd look for a Roadranger with at least 8 gears, but more would be better. Stay away from 6 speed Spicers, you'll tend to get gear bound.

This should be a good thread, I've been interested in doing the same thing, but I'll be using a 6 wheeler. There are plenty of good used trucks with the right specs out there, you've just got to be patient.

 

[DKinWA]

Virtually all the dump/log trucks around here seem to have spring suspensions (hendrickson/chalmers). I figured there must be a durability issue, since most of the trucks around here spend a lot of time off road. I hadn't given a lot of thought to the axle gear ratio, but figured I'd look for an 18 speed roadranger. The truck I have now has the 9 speed and it's a pretty forgiving transmission.

The idea of converting a truck actually came about after shopping for used dump trucks. I can't seem to find one (kenworth or peterbilt) that's affordable that isn't all beat to heck and needs a lot of work. I was thinking that a lot of road trucks are still in pretty good shape and only need the dump gear. Basically I want a truck that is mechanically sound and looks good. I'm not after showroom new, but I'm one of those folks that thinks image has a lot to do with getting work. The last thing I want to do is pull up to a customers place and leave half a dozen big oil spots on the ground where I parked my truck Or worse yet, the truck is always breaking down and putting me behind schedule and costing me more money.

 

[BKrois]

While it may seem like a great idea at first, think of the work involved in converting a tractor over to a dump.

I've looked at some Mack 6 wheeler tractors, but its just not worth converting one over based on the fact that you could buy a 6 wheeler dump for a little more than the tractor.

If the tractor say pulled a flatbed trailer, it probably didn't have a wetline. You might have to install a pto also, pump and other components to power the dump body. Then the cost of the dump body. Used bodies can be found for around $1k, new ones i'd say probably start around $4k. Then you have the installation/fabrication to mount them, painting them, etc.

The contractor i worked for over the summer bought a 10 wheeler tractor to make into a 6 wheeler dump. It's been a year since he started, and its still not done. I don't think he'd want to convert a tractor over again. Lots of little stuff adds up.

If you find a tractor for $5k lets say and a similiar spec truck but a dump for $8k, it might be worth paying more because it could save you money in the long run.

Just my opinion.

 

[Steve Frazier]

Brian, you can buy a 10 year old tractor with high miles but in VERY good condition for about $10,000. Installing a used or new dump body will run $4000 to $8000 depending on how hard you shop. For under $20,000 you can have a class 8 dump in good condition, try finding a used dump truck in good shape for that price.

The reason these tractors are so reasonably priced is due to the number available. Big trucking firms rotate their fleet out after so many years, usually 7 to 10. That puts a bunch of them on the market where the demand is light, so prices go down.

Dump trucks are usually used up by the time they are for sale, and still command a high price due to limited availability. Some of these used truck liquidators have seen the light, and are equipping these used tractors with dumps themselves to get a better price on the same truck.

DK, "Rock and Dirt", a used equipment listing magazine, often lists trucks like you are looking for. Another magazine I believe is called "WorkHorse" and lists both new and used trucks. I just cleaned up my office, these have gone to the trash or I'd have some links for you. When the next issues come, I'll post them for you.

Adelman's Truck Parts sells just about all you'd need to build your truck, the truck, used bodies and PTO pumps. In Rock and Dirt, there's also a hydraulics company that lists PTO pumps and valve units at very reasonable prices. Again, I'll post them when my next issue comes.

 

[digger242j]

It's real common around here to see six or seven year old six wheel dump trucks in the Truck Trader advertised with a "new 10' dump body". It's pretty obvious that some dealers are putting dump bodies on single axle tractors.

Making a dump out of a tandem tractor is probably a bigger challenge, but it's certainly been done. The builder I do a lot of work for has one. They bought it from an excavator who, I believe, did the actual conversion. One of our other members is responsible for the scheduled maintenance of that truck. We talked about it briefly today, and either he or I will try to post the particulars and maybe a couple pics here soon. As you'll be able to tell from the color scheme, it spent the first part of its life dragging trailer loads of Pepsi down the highway.

 

[will_gurt]

I am responsible for the scheduleing of maintence for my employers equipment. I know that the former owner did the conversion themselves. They did change the differential gearing to a steeper ratio. I can't recall what exactly that is at the moment. It came from Kenworth originally with 3.90 ratio.
I would say if you do this make sure that the tractor has a double frame.
This dump has a 350 bigcam Cummins and a Eaton 10 speed. That is more than enough to do the work Digger and I put to it.
We use this truck for general ecavation work and to pull the equipment from jobsite to jobsite.

I would go with the spring suspension over airbag, however. I will try to post some photos of the truck later.


William Gurtner

 

[digger242j]

If I recall correctly, there was another outfit I worked for that had a KW dump without a double frame and they had problems with frame cracking. I'll try to dig up more on that...

 

[DKinWA]

Steve,

I've also seen a lot of tractors (tandems and tri-axles) with 500k+ miles that looked to be in pretty good shape and went for well under $20,000. A lot of them have the 3406 CAT's and 13 or 18 speed roadrangers. I haven't been paying attention to the axle gear ratios, but I will now.

Fortuantely I'm only a couple hours from seattle washington and truck parts are easy to get. I've even seen brand new steel 16.5 foot truckweld dump boxes for $10K and used ones in good shape for less than $5K. I'm thinking with prices like this, I should be able to put a pretty nice truck together for $30K +/- a little. From what I've seen, the hardest part will be finding a truck with the right wheelbase. I've been looking for something around 200 inches and most of them are 220 inches plus.

BTW, thanks everyone for your professional insight.

 

[DKinWA]

I thought I'd add some perspective to my dilema.

What I want

What I can actually afford

Champagne taste on a beer budget :laugh

 

[Steve Frazier]

You can easily shorten the wheelbase to what you need, it's just drilling holes and cutting off the frame rail. You'll need to have the driveshaft shortened too, but it's no big deal.

 

[kamerad47]

I would stay away from a wannabe dumptruck ! The key to a good truck is the frame & suspension, most tractors have single frame they will twist in off road condtions!(you want double frame) Highway tractors have 38.000 lbs rears a light susp , you want atleast 50,000 lbs or better, Tractor spread there weight out with the trailer, a dumptruck with 15 yds of dirt on it is alot of weight on the rear! One more thing tractors don't have big brakes like a dumptruck! Dumptrucks have to be tuff I've been doing this for 20 yrs. I bought new in 95 a Westernstar 435 Cum 8spd LL, 20,000 lbs front axle & 58,000 lbs rears with a T-1 JJ body (it cost $21,000 for it ) the whole truck was $105,000. :usa

 

[Steve Frazier]

I came across one of my old trade papers, Truck Paper.com . There are quite a few dealers listed there that specialize in fleet liquidation. You can do a search on their website or subscribe to their trade paper, I think it comes weekly.

 

[DKinWA]

Thanks Steve,

I'll keep my eye on their site.

 

[digger242j]

Photo Will_Gurt took of the old Pepsi truck:

 

[DKinWA]

Better pepsi than coke

 

[Ole JIM]

Hi Guys in reading this article I noticed some great in-put here!-- & WE GOOFED--YES Me Too! as I forgot a couple of very Important items? in referance too Buying an Ole Over the Road Tractor & converting It to a Dump Truck?--SORRY gettong Old? I got a Brain Cramp?--as I Finally realized most over the Road tractors are specked out a bit Light for making a Dump! especially a twin screw--We all Agree a Wheeler Dump should be a Double frame--& there are a Few Over the Road Tractors w/Double frames so W/that Problem solved!--moving ON--Usually O/R tractors have Higher Gear Ratios--390s &370s-but- theres a few lower ones--Macks have a lot of 4.17s & on Macks their Rears greas are installed up-side down & changing grear Ratios is Simple--No Problem There!--on most other Rears? well you can*t have Every thing?--& just for the Record!-- & for aa all around Dump truck You don*t Need 58.000 lb Rears!--& you won*t Find any on over the Road Tractors--so Forget the BULL Rears! as O/R tractors usually have 34s & 38s--& once in a While? You may run into a 44?--more often than You Think!--yrs Ago ROCKWELL had a lot of E*M out There!--& most O/R tractors especially Late Models have Big Power!--unless thier a Fleet Truck? w/ the De-Tuned Engines?--I personally Prefer the 13 speed R/R in the Tranny Dept--& WE all Forget--YES Me too!-that Front AXLE!!--YES I --Know! I*M getting OLD--as most O/R Trucks come w/12.000 lb front axles--a Real NO NO on a Wheeler Dump Truck!--& a Wheeler Dump should have a 16.000 lb front Axle!--& YOU all can Give ME HELL! & rightly SO I know I deserve IT!--& I if It were MINE? would Add twin Power Steering!--& stay Away from Floation Tires on my Front END!--YOU know Those BIG WIDE Ones!--& YES! in Dump Trucks BIGGER & BETTER is the Way to GO--But-were trying to build a Wheeler DUMP Out of an O/R tractor REMEMBER!--So lets Not get PICKY! WHEW! Hope I got Out of That ONE?--& YEH! Getting OLD is a BITCH --Ole JIM--

 

[littledenny]

Just a couple other things to consider with a O/R tractor converted to a dumptruck:

Often a tractor has a big, low hanging fuel tank, or dual saddle tanks with a cross over pipe that hangs down in the way of good ground clearance. Exhausts often hang a bit, too. While neither is a huge problem, it's something else you need to consider in a conversion.

The truck the outfit I recently worked for had a old Ryder tractor converted to a dump, with all the problems everyone here is listed. That darn thing was more trouble than it was worth.

Best advice - I you want a dumptruck, get a real dumptruck. THink Ole Jim hit it on the head.

 

[gslam88]

Guys,

As far as converting a Class 8 ( which is a truck 33,000 and more) to a dump... it first would start with what kind of work your going to be doing or needing. You could go with a 6 wheel truck if your doing small tight work in say customers back yards and your need a short 10' body. Something like a International 4900 or a Pete 330 would be good. As Steve said a Cab and Chassis could be gotten inexpensively. You do want a double frame for this. This is usually a 33,000 to 35,000 lb truck, it will hold about 20K worth of material.. depending on trucks light weight.

Then there is the Tandem trucks having a 14' to 15' body Running somewhere around 53,000 to 55,000 or so. You will probably carry about 25K worth of material again depending on light weight.

Then is the Triaxle having a 16' to 23' body. Runing about 76,000 with overweight permits... this will vary with bridge formulas per state. The calcuations for the formula does include the number of axles, distant between axles and other pieces of information you will probably carry about 30K worth of material. again this will vary by several factors

As far as an off road dump truck and air bags. It is not recomended for most applications. The spring susspension, and this has several names by various vendors, chambers, camelback, hendrick, etc is the better choice by my opinion. If your doing very little off road then air bags are ok, but remeber with any truck. The longer the body the more important the truck is level and flat.

On gearing for the truck, there are some trucks that have low and low low trannies.. your will see them as and example as 8L or 8LL ... with a low gearing in the tranny it can make up for a little higher rear end gear. There is also a 2 speed rear end on some class eights. You mostly find these in 6 wheel trucks. The heavier trucks tend to split the tranny not the rear end.. .. The international that I had was a 4.56 with it in low gear I think that made it a 6.38 or so.... 2 speed rear end


A couple other peices of information. A truck with no sleeper on it is called a day cab. As far as someone saying get a real dump truck. I am not sure what they mean by that exactly.. as you can setup just about any truck how ever you want. I have seen sleeper dump trucks, is it the kind of thing you will see pullling into a backyard of a homeowner in tight area, no. However if you setup what ever truck you want correclty it does not matter if it started off life as a OTR or a city truck or a garbage truck.

The other thing to keep in mind that I don't think I saw anyone talk about is underpowering a truck. This is something to pay attention to also. Never Never underpower a truck for what you plan on doing with it. If you put a 215hp motor in a Triaxle you will lose you mind on going anywhere...

depending on the truck setup I would personally say go with a 230-260 hp on a 6 wheel... the 215 hp that I had on my 4900 was ok.. but when fully loaded going up hill was a little slow...

on a tandem... 300-350hp could be a good range...

on a traxle ... 400+... obviously the more the better..
a nice 600hp motor on a triaxle is sweet...

Most of what I have said is my opinion... so take it like everyone elses opinion...

Jim... on 58 rear.. Mack tend to run them often it seems... on their triaxles...

Pete