Hey guys, new here and this is my first post. I own and run my own tri axle dump (LT9000 with 3406B and 8ll), also have a 20 ton tag trailer and do local equipment moves, before this I spent 8 years as a mechanic and do all my own wrenching as a result. Long story short a deal on an '87 Peterbilt 379 road tractor came up that needed a power divider, price was right and I jumped on it, for what I have into it I could flip it for a profit or get into the end dump market. I have a good relationship with local contractors and quarries so I think getting into the end dump world may be a great opportunity to expand the business. In NY we can get legal for 107,000 with a tri axle trailer and tandem tractor, id like to put a business plan together with decently accurate numbers before I drop the money on a trailer. One of the unknowns is fuel usage on a 10 hour day of local run (lots of stops and starts) with a 3406C mechanical motor (non PEEC) at this type of weight. Truck is obviously a billboard aerodynamically, 15 speed non overdrive tranny, tall rubber and pretty steep gears, I have to double check the ratio but I think they're 3.90's in 44k axles. A local day with my tri axle truck running 10 hours port to port has never using about 35 gallons of fuel with a 3406B non ATAC (7FB prefix). I'm also going to project my fuel costs at 6.50/gallon because that's what it got up to at one point this summer, and even though it's 5/gallon right now, im in NY so I expect all things that suck to happen. Thanks guys and I appreciate any input, especially the older owner operators who have been there and done that with an old mechanical. -Pat
I’d say with that weight 4.5-5 mpg depending on how you drive. My buddy ran a fleet of older Pete’s running dump trailers on Long Island with drivers in them, and that was about the magic number across the board. A owner operator doing the driving and watching his right foot you could definitely do a little better. I’m about 5.8-6mpg across the board with a WJAC 3406B Pulling a step deck. The 3.90s and non OD 15 speed may hurt you when empty, loaded it should pull very well I’d say.
Thank you for the input 379! If I was getting 5mpg in a local heavy haul route I would actually be ecstatic, the idle times are high and the hills are big where I run. My 3406B WJAC like yours only manages about 4.5mpg in this application, however it's a dead stock CAT reman motor, I gotta call cat with the serial number one of these days to figure out where it's set, but its either 350hp or 400 and when you're loaded in high range your generally in the throttle pretty well. I shift progressive and never go over half throttle when empty to help with the fuel costs, but ive cone to terms with the fact the older mechanical Cats like their fuel. The C may have a chance at better mileage though than my B because of the Air to Air cooling and it's a factory 425 motor, not sure though and that's why I'm asking.
I can tell you that local dump work is extremely variable on fuel consumption…i have done jobs where the average with several trucks will be around 4.8 and other jobs we barely squeeze out 3. I can think of a particular road building job with a 2 mile hilly each way trip and working on a soft dirt road where literally the highest gear you can pull loaded is 6th we got around 2.5 but we were running hard and the money was good. This is with 855 mechanical cummins in l series fords and a w9. Just for reference if I drive my w9 (small cam 855 with air to air aftercooler that runs good) with a short dump and take my time I can get dang close to 6 with 8-12 one way mile trips and a quick dump at the job. We are running around 74-6 k though not 100+
I want some pictures of that lt9000 I am curious how big of a pita it is to work on the engine. I am thinking of switching this one to 3406 cat
Mid 4s, at best, loaded both ways with hills will be even less and if you are staying in NY, get a quad for 117k, or if you have room To add a pusher you can do that as well
I'll try and get some better pictures, thats just what I had on my phone, nut it's not bad at all really. The LT has more under hood room, a straight L model might be bad. It's basically just half of cylinder 5 and all of cylinder 6 that are in the doghouse area.
My 3406B without air to air cooling (water jacket air cooling) gets like 6-7 empty if you keep the rpms at 1500-1600 at cruise, but in a dump I don't find myself empty much. Also the truck is very heavy empty, weighs in at 30,000lbs dead empty.
