What do you look for in a used tandem or tri axle dump truck? New trucks are expensive as Im sure everyone knows, but Im a little scared of buying a used one. I need a truck that can haul good but one that also has the power to pull a track loader. How many miles is to many on a truck? How much power is needed to pull 35,000? We currently have a KW tandem with a cat 3306 I think it has 300hp. I would like a bit more but that motor might just need to be rebuilt. Thanks Mark
Hello Osborneconst,and welcome. Alot of the choices would be brand preference,for the complete vehicle,and the components.Everybodies going to have different opinions on that,but what I'd look for in a truck: Diesel Engine:inline 6 cylinder w turbo.Some common ones that have a good reputation are Cat 3406(any letter suffix,prefer E)Cummins L10,M11,N14,ISX, Detroit series 60.(many other's too,can't think of them off top of my head now) 300hp,1150 ft/lbs torque min. prefer 400hp+,1450 ft/lbs torque or more.(the smaller the engine,the more gears you'll need) Transmission:Eaton Roadranger 9,10,13,15,18 speeds(more gears the better) I personally don't care for the Rockwell transmissions,but I do like their rear-ends.The Allison auto's are good but with the gross weight your looking at(20k truck,35k trailer & equip,30k dirt/gravel)you'de be pushing the their limits of ability. Rear-ends:Eaton or Rockwell/both good.40k or more capacity. Suspension: preferably air ride,but not a necessity. Brakes:air brakes. Wheels:I like bud rims 11R22.5 tires Obviously the lower the miles the better,but the mileage is not as important as the maintanance.It's not uncommon for the engine,tranny,rear-ends to go 1mil. miles before overhaul in OTR application,dump trucks much less,but 500K probly not uncommon there if well maintaned. Hopefully the truck will be cold when you look at it.Fire it up,and see how quickly it starts.Most will fire quickly,if it's 50 degrees or more outside(almost like a car).Smoke on startup isn't as big a deal as on gas motors.If it's pouring out blue for a long time after start-up,then it may be well worn,but some blue or black can be expected.Some motors are noisy also,so it's hard to say that they shouldn't have any mechanical noise while idling.Once on the road,you should NOT be able to hear mechanical noises from engine though.Also look to see how fast it builds air.If tanks were empty 0-130 lbs should be less than 1 minute.Some compressors are noisy while building air,but are not necessarily worn out. Look for engine,tranny,rear-end seal leaks.Tires at least 8/32" depth(30% life left)brake pads min 1/3" left(min. by law is 1/4").Purge air tanks at the petcocks,and check for water or oil.Water or oil means air dryer is towards end of life,oil may additionally mean compressor is on the way out too.Listen for air leaks in air system after shut-down.Check u joint play,pinion play,they shouldn't have any. While driving,the steering should not have alot of play,or wander excessively.The truck may have tires out of balance,out of round,or if dayton rims are not mounted true,it may shake,and vibrate at road speeds.That's more common than not,so it's not necassarily a problem.When braking it should slow down smoothly,no shuttering(out of round drums). I've probly left alot out,but hopefully others will throw some ideas at you too!! Good luck.
The 3306 is a little small its the same class as the M-11 L-10 Cummins your okay for general use but you will never beable to pull a pony trailer. You are sticking with the right brand truck you can't go wrong with a Kenworth if its a T-800 or a W-900 it sounds like you may have a T-450 which was common to use the 3306 or L-10 as the hood wouldn't fit a bigger engine. Myself I wouldn't own a air ride dump truck its not stable enough as for rear axles minimum 44,000lbs the 40s are just too light for offroad useage. For power 14 litre engine so you would be looking at N-14 Cummins or 3406 Cat. My transmission of choice is either a 13spd or 18spd you can get away with a 8LL but more gears the better. A 9-10 spds are not good enough a 15spd is okay but how much are you really going to use the deep reduction gears.