best engine/transmission choice for a dump truck - 26-33k GVWR

[oifla]

hello all,

i understand this kind of question is likely going to get into personal preferences and is largely opinion based but i'm still curious to hear about experiences folks have had.

i'm looking to get into a slightly more capable truck than what i have now. would prefer to stay with the single axle (space and access are important for me) but i would like to find something with more GVWR (~33k GVWR would be good for my needs). if the right truck comes along and it happens to be a tandem, that's ok but I'm really looking for a single axle.

my first truck was purchased from an aquantaince and it worked out well enough but i want something with a manual transmission (current rig is an allison auto).

what engine/transmission combo i should be looking for? i usually only haul gravel and i'm going to be buying an older truck (my budget is $12-18K). thanks all

o.

 

[catbuster]

Easiest to drive would probably be a 3306 Cat with a 5 speed (Eaton-)Fuller transmission and a two speed rear end.

Finding a 3306 in a single axle is probably rare, and most of them are probably paired with an 8LL, which is not a synchronized box, and they earned the nickname of “crash box” in places where both Euro-style sychro boxes and the American transmissions are both used. It would take some time to learn.

A Cummins C8.3 is a good engine, very easy to drive and again I’d prefer mated to a 5+2, Fuller over Spicer, though they’re both pretty easy to drive. I prefer the Fuller because the gears are a little bit more spread out on the shifter, it’s easy to miss 3rd and accidentally shift into 5th on the Spicer transmissions I’ve driven.

International has all the iterations of the 466, and they were & are good, even if none would ever be confused for a rocket ship, but they are very straightforward to work on and other than the occasional oil leak are dead reliable and run for a long time.

Cat has the 3116 and 3126 that were also very popular in that segment. I would not go smaller in displacement, though.

For a new truck in that size range with a manual transmission I would probably spec a Cummins L9 mated to an Eaton-Fuller synchronized 6 speed box. But honestly, the Allison autos in that size range are really good and make life a lot easier to drive.

 

[catbuster]

I’ll add that of all of the engines other than the 3306, the C8.3 would be my pick. They have great pickup and they’re easy to drive because they make good power basically anywhere ~1200-2000 RPM. Parts are plentiful, and they’re pretty easy to work on. These engines were used in all sorts of stuff, from farm equipment to trucks to construction equipment to oil rigs, gensets and mine sites.

The 3116 was kind of a problematic engine, and the 3126 electronic controls with HEUI system was better, but still kind of a throwaway engine.

You may also see a Cat 3208. The 3208 was a V8, in the same ~10L displacement category as the 3306, that I had in a fire engine and another in a tender. They were okay for us, but the engine had 40,000 miles and 3800 hours put on it from 1986-2018. The tender had 45,000 miles and 3000 hours on it from 1987-2017. The engine was dry sleeve, and was meant to have a wide array of applications, it ended up being best suited in Marine applications where it was under constant load.

And I forgot to mention Detroit diesel… They’re all easy to work on, at least once you get your head around how they work, because it truly is unique with forced air induction being a literal requirement for them to even run.

To drive one it’s best have a lot of gears to use and low reduction to take off because the power band is really narrow, probably around 300 RPM and close to where the engine overspeeds. They’re loud, hard on fuel, but were, for whatever reason, very popular.

Common models in medium-duty trucks, fire trucks and buses were the 6-71, 8V71 and maybe, just maybe you’ll see a 6V92 or 8V92 in a tandem dump. T on the end means turbocharged, TA means turbocharged and aftercooled. Those engines will run away in a heartbeat, so be careful for oil seals leaking if you buy one.

 

[oifla]

Thanks Sean, I appreciate your time and expertise on this question.

I'm looking around and seeing what's out there. There are some DT466 powered Internationals fairly close so I'm going to test drive one and see how it goes.

My current rig is a 3126 with an Allison. It's probably one of the better autos i've driven but I prefer rowing through the gears and I do need a little more GVWR than this truck is capable of.

o.

 

[Stump Grinder52]

Along with what cat buster suggested, I would like to add being a retired fleet mechanic/tech for a trucking co and running a repair facility, have seen many concepts of tractors come and go.Simplicity was always the key to low maintenance. The 2 speed rear end was always the [Weak Link] in the drivetrain, second would be Road Ranger [splitter] transmission.If you looking for a used truck, you might look at Ryder or Penske turned in lease unit, they should be able to supplied you with a complete service record since truck was new.Their usually pretty strict with maintenance.You can sometimes get something turned in in very good condition.

 

[northmanlogging]

Ideally I'd steer ya towards something with a 10spd which also means air brakes, but also means you can pull more with a trailer, but you will need a CDL.
Otherwise any 5+2 combo works good, especially with more modern axle shifting mechanisms (if its electric make sure the housing is more square, and doesn't have a little starter motor sticking out the top... these all have issues, and is one of the reasons the DOT frowns on folks shifting gears over railroad tracks...)

Any Cat engine will be a good engine, though having ran a 3208 in a 10yrd tandem truck... it wasn't exactly winning any races but it was very very hard to kill, and still ran like a top as the rest of the truck rotted around it. Only problem is finding Cat engines in newer trucks, as cat decided they simply are not going to play the emissions game. Also the 3208's are getting hard to source parts for, not impossible, but difficult and expensive.

Older Cummins engines are skookum, any of the NTS big cam stuff, and the 5.9/8.3 family of stuff is rock solid, some of the newer stuff has the usually sensor gremlins that plague everything (see why cat bailed out) but they are all more or less based on tried and true internals.

International DT466/540 are skookum choochers too, not the most powerful but more then enough for a 33K truck

As for Destroit (detroit/gm) while they sound cool, and parts are literally everywhere, probably even walmerch... they piss oil, and make more noise then they do power, but will eat ether for decades to keep running if they have too, the newer (silver?) 4 stroke Destroits have a decent rep with the OTR trucks, but only because like all GM stuff, the parts are cheap.

if you find one the ford branded diesels, other then the 6.9/7.3(which are really IH) stuff the inline 6 are good motors too, a PITA to prime if you run em out of fuel, but good strong motors.

 

[Stump Grinder52]

Pre emission engines would be the key, pre 2006, no EGR ,no DPF, no DEF, less problems

 

[capetrees]

I ran two different U model 6 wheel Macks years ago. One was an Econodyne and the other had the E7 Mack engine at 300 +/- HP, one had the 5+2 split, the other a straight 5 speed. I never put those trucks in 5th gear ever as I had enough speed in 4th. The low end power was huge. The 6 wheel wheelbase allowed ne to turn on a dime. Both were 33k GVWR. I changed jobs and didn't need them so I sold them. If I had to get truck, 12-18K, I'd look for another mack. The U models are pretty much non existent but the R models are out there. Look around. Damn good trucks.

 

[catbuster]

@northmanlogging I strongly disagree about four stroke Detroit Diesel engines… other than them being silver. They are the only game in town for the fire service here in town and I haven’t seen one let anyone down yet.

For 3208 parts, try a Cat marine dealer.

I forgot about Mack, probably because I only have experience with one truck that had an E9 V8 and a 5 speed maxitorque transmission that I hated. Nothing wrong with it, but it was around 900 or 1000 RPM between gears and the truck would let you know if it was anything different. You could pull it out of gear, eat a full lunch, then you’d be just in time to grab the next gear at 1200 RPM.

 

[northmanlogging]

not saying the 6.9/7.3 ford stuff is bad... the powerstrokes are pretty skookum and older IDI engines are bullet proof but low on power.

 

[northmanlogging]

@northmanlogging I strongly disagree about four stroke Detroit Diesel engines… other than them being silver. They are the only game in town for the fire service here in town and I haven’t seen one let anyone down yet.

For 3208 parts, try a Cat marine dealer.

I forgot about Mack, probably because I only have experience with one truck that had an E9 V8 and a 5 speed maxitorque transmission that I hated. Nothing wrong with it, but it was around 900 or 1000 RPM between gears and the truck would let you know if it was anything different. You could pull it out of gear, eat a full lunch, then you’d be just in time to grab the next gear at 1200 RPM.

Yeah, the new Destroit stuff is pretty good for reliability... I just have a problem with GM lol

 

[catbuster]

Yeah, the new Destroit stuff is pretty good for reliability... I just have a problem with GM lol

I have a problem with GM, every company/agency truck I’ve ever been issued has been one, and they have all sucked. Then government motors, bailouts, yada, although I did drive through a tornado in one…

I own and drive Ford products, almost exclusively. Up until a few years ago I drove a 7.3 Powerstroke, that truck built a mid-size civil construction firm, yada.

 

[Butchmalung]

I have a problem with GM, every company/agency truck I’ve ever been issued has been one, and they have all sucked. Then government motors, bailouts, yada, although I did drive through a tornado in one…

I own and drive Ford products, almost exclusively. Up until a few years ago I drove a 7.3 Powerstroke, that truck built a mid-size civil construction firm, yada.

Got to second the 466 with an Allison Auto. I have an 80's single ax corn binder dump, 466 b/c (before computers) w/Allison, bullet proof. I'll put that combo against any other on the road or in the pit. Watch your state, local,and federal auction sites. I got mine for under $4k, with150k on it.

 

[calamari]

Years ago I drove this watertruck for awhile. It belonged to a friend who collected Peterbilts buying the last one produced in the two years he was interested in. He was a sprint car racer so he had to hot rod everything and he did that by putting a bigger fuel pump on his trucks to boost the power. I don't recall all that he did but it was more powerful over a stock model Pete.
The reason for the post was that it had a 5 speed main gear box with a 4 speed splitter and both had that semi useless Faux synchro system. It takes awhile to learn it but once yiou do you can be very fast and efficient with the system. They were double tough gear boxes. One quirk of the system was that it had air actuators for the PTO to run the water pump and monitor valves. One the PTO was engaged you could use the clutch to take off but it would not disengage when shifting so you had to shift w/o the clutch matching ground, gear and engine speeds. Quite a dance. If you look at a truck with similar gearboxes and PTO needs drive it around in all configurations to see how you like the semi synchro.

 

[catbuster]

Years ago I drove this watertruck for awhile. It belonged to a friend who collected Peterbilts buying the last one produced in the two years he was interested in. He was a sprint car racer so he had to hot rod everything and he did that by putting a bigger fuel pump on his trucks to boost the power. I don't recall all that he did but it was more powerful over a stock model Pete.
The reason for the post was that it had a 5 speed main gear box with a 4 speed splitter and both had that semi useless Faux synchro system. It takes awhile to learn it but once yiou do you can be very fast and efficient with the system. They were double tough gear boxes. One quirk of the system was that it had air actuators for the PTO to run the water pump and monitor valves. One the PTO was engaged you could use the clutch to take off but it would not disengage when shifting so you had to shift w/o the clutch matching ground, gear and engine speeds. Quite a dance. If you look at a truck with similar gearboxes and PTO needs drive it around in all configurations to see how you like the semi synchro.
View attachment 958671

I can not recommend enough against a 5x4, 6x4 or other twin stick arrangement. You probably won’t see in in a single axle dump, but they’re a pain in the ass to drive and a product of a bygone time when trucks made 200 horsepower and had a power band from 1800-2100. (Cough, Detroit 6-71, cough) The running joke in those trucks was that if you didn’t have a hand on a stick was that you were lugging it or winding it out too far. I think I’d actually rather drive one of those ornery Mack 5 speeds with an END864 because at least that engine was so forgiving.

 

[calamari]

It was different for sure but his trucks had power and with 50,000 pounds+ when fully loaded it had good traction and strangely good handling too. Power wan't an issue in that truck but getting used to twin sticks did take awhile but once you figured it out you could be amazingly good at keeping it on the boil. From a past time for sure but I see that truck on the road still so... Road Rangers felt awfully "tentative" in their shift patterns after that old setup.