Best classic conventional Pete for tandem dump?

RenoHuskerDu · Sep 27, 2019

Hi guys, I haul a 3-axle lowboy dump local only, mostly to quarries, in the TX country with with an F350 drw. The trailer is 21k lbs max, the truck can tow 32k, no problem. I often hear guys like me saying "why didn't I buy a tandem dump a long time ago?" Double loads sound good. So I'm gonna buy one. I'm running fine now, and I can take my time to find the right truck.

There's a boatload of Petes out there. I know I want 46 rears, air dump if it's a converted tractor, and 350 hp at least so I can tow a trailer with a hoe or skiddy in a year or so.

What I don't know is which motors to look for other than Cummins and 3406 or 3408 Cat. If it's a Cummins L10 then avoid the STC like the plague. That's about all I know. I don't know about DDs at all.

I checked out https://infogalactic.com/info/Peterbilt and the models that grab me are 348, 353, 357, 359, 378, 379. Did I miss any? I don't like the looks of aero trucks. Yeah, my choices in the classic market are going to be slim. I might only find 2-3 of these models for sale within reasonable drive time.

AzIron · Sep 28, 2019

Good luck on a 3408 but you would never be late to a job again

3406 is bullet proof not stupid proof cats are pretty decent till you get to the Acert motors

Cummins n14 seem solid so does an ism and isx I have never been a Detroit guy but I know guys that wont run anything but

Good for you being dead set on pete but you might close yourself off from other decent options I personally would look at kw int maybe ford for the right price

The majority of it comes down to maintenance and how much or little they did

Mother Deuce · Sep 28, 2019

3408 in Texas... they used to be there by the bushel basket. I have run a 3408 in the dirt. It needs to have some really stout components behind it. Most of the Texas trucks were highway queens. I doubt there are few engines right now that more expensive to maintain and repair than a 3408. I love them but wouldn't get another. A 3408 in a ten wheeler is a little like taking a nuke to a gunfight.
I had a 359 with an 18,000 pound front axle, "4 and a quarter horse" 3406 B ATAC, a 13 later 18 spd and 2spd Eatons. I bought the truck new in 86 and sold it 99. I did the roll in the rod bearings at 250,000 as recommend by Cat at the time. We got in the engine at 500,000 when it broke a ring. Beyond that, it was pretty much trouble free. Air dump?? I assume you mean tail gate? I had no idea that anybody still had a handle on the gate except one ton mason dumps.
Find a well maintained truck that was built to be a dirt truck. I have seen very very few "converted highway tractors" that are worth anything as a dirt truck.

Truck Shop · Sep 28, 2019

Detroit DDEC 3 or 4 12.7L standard rating 435 hp can be rated to 470 and up to 500 hp, torque rating 1550 to 1650. The 12.7 liter in early DDEC 3 GK series up to 1998 470 max,
later DDEC 4 1998 and up 500 hp. The 12.7 is about as reliable as it gets. And any DDEC 4 14L 550 hp will set right in place. As far as Cat goes any thing in 3406 5EK up to C15 2003
Any of the N14's are good but on a re-rate a 370 hp from factory will only re-rate to 435 hp. Personally I would stay with electronic engines. 3408 is heavy and to expensive to repair plus
damn near any six cylinder will out perform it in torque and hp these days. Most OTR trucks don't have the axles and frame for a dump, do some smart shopping. As far as transmission
a ten spd in Texas will work fine.

bam1968 · Sep 28, 2019

It's not a Pete but it's a classic!!! Put about 200 miles on it yesterday hauling gravel. I would hate to part with it but you bring a nice thick envelope of cash and you could drive her home!!!!

Mother Deuce · Sep 28, 2019

bam1968 said:
It's not a Pete but it's a classic!!! Put about 200 miles on it yesterday hauling gravel. I would hate to part with it but you bring a nice thick envelope of cash and you could drive her home!!!! View attachment 202409

I drove one of those forever ago a 270 and a 10 speed. Heavy steering but wore like concrete.

RenoHuskerDu · Sep 28, 2019

Mother Deuce said:
I drove one of those forever ago a 270 and a 10 speed. Heavy steering but wore like concrete.

I see a red IH with a mid tag axle and day cab. I forgot to mention that I'm 6'6" so cab room is important. What's the motor, tranny, rears, etc? Never been to IA yet. TX is so big that you can drive all day and still be here.

Regarding air dump, what I mean is that IF it's a converted tractor with air bags, it's got to have air dump too, or the bags get abused when you tilt to dump.

bam1968 · Sep 28, 2019

RenoHuskerDu said:
I see a red IH with a mid tag axle and day cab. I forgot to mention that I'm 6'6" so cab room is important. What's the motor, tranny, rears, etc? Never been to IA yet. TX is so big that you can drive all day and still be here.

Regarding air dump, what I mean is that IF it's a converted tractor with air bags, it's got to have air dump too, or the bags get abused when you tilt to dump.

It has 6-71 Detroit with a 13 spd trans and IIRC 4:11 rears. I'm 6'1" and there is plenty of room for me..... 6'6" might be a little snug.

RenoHuskerDu · Sep 28, 2019

I just checked this one out. 1986 Freightliner Dump, Cummins Big Cam 4, 400 hp, 13 speed. Converted from tractor, still has slide lock on dash, but simple leaf springs. Tach and Speedo both inop but 240k show on the odometer. Needs work on dump cylinder, which leaks, and a lot of TLC for loose wires that need to go neatly into split loom. He says gears are long and 13th is good for 75 mph, which I don't need. 60 will do. Started up real quick, sounds good, but the owner has let insurance lapse so doesn't want it driven, even to a shop for inspection. Nice guy, but I think I'll pass at $12k. If he keeps lowering the price as he says he has then I might take it. I didn't set out to look for a Freightliner but he lives nearby. Also, the seller tells me that they have roomier cabs than Petes, and I'm 6'6"
Do you agree about Freightliner cabs being bigger?
I do like the Cummins. No leaks on it, just some sweatin oil. Course it hasn't run regular for months so who knows how much it might leak if used daily.

Mother Deuce · Sep 28, 2019

RenoHuskerDu said:
I see a red IH with a mid tag axle and day cab. I forgot to mention that I'm 6'6" so cab room is important. What's the motor, tranny, rears, etc? Never been to IA yet. TX is so big that you can drive all day and still be here.

Regarding air dump, what I mean is that IF it's a converted tractor with air bags, it's got to have air dump too, or the bags get abused when you tilt to dump.

I am going to be pointed... because I feel it is important. Air Bags are not an acceptable suspension in a dump truck period. Not sugar coating it. Go ahead and do it. Just make sure you carry an extra pair of underwear. You will need them the first time it goes on it's head or threatens to.

RZucker · Sep 28, 2019

RenoHuskerDu said:
I just checked this one out. 1986 Freightliner Dump, Cummins Big Cam 4, 400 hp, 13 speed. Converted from tractor, still has slide lock on dash, but simple leaf springs. Tach and Speedo both inop but 240k show on the odometer. Needs work on dump cylinder, which leaks, and a lot of TLC for loose wires that need to go neatly into split loom. He says gears are long and 13th is good for 75 mph, which I don't need. 60 will do. Started up real quick, sounds good, but the owner has let insurance lapse so doesn't want it driven, even to a shop for inspection. Nice guy, but I think I'll pass at $12k. If he keeps lowering the price as he says he has then I might take it. I didn't set out to look for a Freightliner but he lives nearby. Also, the seller tells me that they have roomier cabs than Petes, and I'm 6'6"
Do you agree about Freightliner cabs being bigger?
I do like the Cummins. No leaks on it, just some sweatin oil. Course it hasn't run regular for months so who knows how much it might leak if used daily.

That cab is quite a bit roomier than a Pete cab, I've had both. The 12064 Freightliner is not a bad truck if its been taken care of.
Check out the dump cylinder well, if the stages are "washboarded" or scored it's cheaper to buy a new one than to try and repair the old one. About $1500 for a new one. What does it have for spring suspension?

Birken Vogt · Sep 28, 2019

It is mountainous here and air bags are used on dump trucks all over. Just saying.

RZucker · Sep 28, 2019

Birken Vogt said:
It is mountainous here and air bags are used on dump trucks all over. Just saying.

I've dumped over banks at an angle with Hendrickson and nearly had one set of duals hanging in the air. No way in h$ll would I get close to the edge with air bags. They are ok for road dumps, but for real dirt work... no thanks.
Even heavy 4 spring Reyco would be better than bags.

RenoHuskerDu · Sep 28, 2019

RZucker said:
That cab is quite a bit roomier than a Pete cab, I've had both. The 12064 Freightliner is not a bad truck if its been taken care of.
Check out the dump cylinder well, if the stages are "washboarded" or scored it's cheaper to buy a new one than to try and repair the old one. About $1500 for a new one. What does it have for spring suspension?

Thanks for the cylinder advice. My son worked heavy equipment repair for a while and said "ugh" when the guy mentioned repairing the cylinder. Same guy has a backhoe sitting in a pool of hydraulic oil, not even working. He's not Mr Maintenance, shall we say. Real nice guy though.

As far as the springs go, I just saw leaf packs back there with a rocker in between. Pretty much classic. What should I look for? I'm just learning big trucks but have been wrenchin on stuff since I was 9, first minibike.

RenoHuskerDu · Sep 28, 2019

Some folks really like the Cummins 855 Big Cam
https://www.capitalremanexchange.com/best-diesel-engine-list/

Birken Vogt · Sep 28, 2019

Those guys are a little too enthusiastic on their best/worst list there. You are going to have to take each truck as it comes. You may see 9, 10, 11, 14 liter engines from all manufacturers, some were good, some bad, along with various combinations of transmission and suspension, just take your time.

RZucker · Sep 28, 2019

RenoHuskerDu said:
Thanks for the cylinder advice. My son worked heavy equipment repair for a while and said "ugh" when the guy mentioned repairing the cylinder. Same guy has a backhoe sitting in a pool of hydraulic oil, not even working. He's not Mr Maintenance, shall we say. Real nice guy though.

As far as the springs go, I just saw leaf packs back there with a rocker in between. Pretty much classic. What should I look for? I'm just learning big trucks but have been wrenchin on stuff since I was 9, first minibike.

4 springs with a short equalizer in the center is probably original Freightliner, possibly Reyco.

Truck Shop · Sep 29, 2019

Most all of the heater/Ac controls and vent door air actuated parts are not available for that early FL cab anymore. Salvage yard only. Rear suspension is probably Freightliner spring and
most of that was only rated at 38,000 lb, if it was Reyco 102 series it could have a rating from 40,000 to 44,000 lb. The best rear suspension for a dump is Hendrickson 48,000 lb--
60" spread extended leaf walking beam. It is the most stable and has the best traction of any suspension because of the 60" spread. I know loggers that run 60" spread, would walk right
out and past one with 52" spread that was chained up. Canadians liked to spec their off road with SSHD drives and 60" walking beam.

Need some photos of that Cummins setting between the rails for a look see, to note which series BC 4 it is.

92U 3406 · Sep 29, 2019

If I was looking at a dump truck, I'd want 46k rears, full lockups, 4.10 ratio. Neway air ride, heavy steer axle, heavy single frame (double frames spread). As for power, can't go wrong with an N14, 3406/C15 or a 12.7L Series 60. Definitely an 18 speed or at least a 15 speed.

RenoHuskerDu · Sep 29, 2019

92U 3406 said:
If I was looking at a dump truck, I'd want 46k rears, full lockups, 4.10 ratio. Neway air ride, heavy steer axle, heavy single frame (double frames spread).

Where do I look to find out if the axles are 46k, 48k?
Full lockups means locking both left/right and f/r on the tandem, right?
Axle ratio, I'd look for a tag on the pumpkin. Worst case, jack up one side, mark the diff, turn the tires.
Heavy steer axle, how to judge that? Look at 100 trucks?
Single vs double frame, must be visual inspection.
Are my assumptions all correct?

Truck Shop said:
Most all of the heater/Ac controls and vent door air actuated parts are not available for that early FL cab anymore. Salvage yard only. Rear suspension is probably Freightliner spring and most of that was only rated at 38,000 lb, if it was Reyco 102 series it could have a rating from 40,000 to 44,000 lb. The best rear suspension for a dump is Hendrickson 48,000 lb--60" spread extended leaf walking beam. It is the most stable and has the best traction of any suspension because of the 60" spread. I know loggers that run 60" spread, would walk right out and past one with 52" spread that was chained up. Canadians liked to spec their off road with SSHD drives and 60" walking beam.

Need some photos of that Cummins setting between the rails for a look see, to note which series BC 4 it is.

Is this an accurate diagram of Extended leaf walking beam?

leaf-spring-walking-beam-German-mechanical-suspension.jpg_350x350.jpg

Or is this Hendrickson page more accurate? https://hendrickson-intl.com/Truck/Vocational/RT-RTE

Is the "spread" the width between the U-bolts on the leaf packs at the axle pad? So, seems logical that wider would be better for stability. But frame width would dictate how much spread is possible, right?

Where would I look on the truck to see if the rear suspension is FL or Reyco? Numbers cast into shackles etc?

I'll get some pics.

Best classic conventional Pete for tandem dump?

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Charter Member

Senior Member

Senior Member

Senior Member

Charter Member

Senior Member

Senior Member

Senior Member

Senior Member