freightliner fc80 with cummins 5.9 engine...will it tow?

[soapstoneguy]

Looking at buying the above truck. Seems in good shape with a dump bed on it which is nice. It has a 5.9 cummins and curious if that will tow a 16k excavator on a trailer that is rated for 24k?
Would like to find an 8.3 cummins as I know that would for sure but they are pretty hard to find.

Not trying to win any races I just don't want to be pushing that engine and trans at 100% all the time you know.

Any feedback from guys who have experience with them would be appreciated.

Thanks!

 

[Acoals]

It will move it, you won't be winning races or keeping up with the shiny new pickups, but you won't owe 90k on it either.

I drove a box truck with a 5.9 and a 6 speed, it would gross out maybe close to 30k. It was fine for power, but would slow down on hills a bit loaded. It was the same with the old Blue Bird All American busses with that engine. They got the job done, just made a lot of racket doing it rather slowly.

 

[MG84]

IMO the 5.9 cummins is just too small for a medium duty truck, unless it’s a light or low usage application (bucket truck, box truck, etc) They don’t have near the low end torque or engine braking that the larger displacement engines have. What transmission, rear axle/gearing does the truck have? If your terrain is fairly flat it may do ok, but I personally would pass.

 

[Birken Vogt]

The OP states he is in Oregon and most places in Oregon towing a rig like that up and down hills might be a bit slow. If it was flat country it might be different.

 

[crane operator]

Truck is going to weigh, 12-14k? plus 16 of excavator, plus another 5-6k of trailer. 34-38,000 gross? If you have enough gears and low enough gearing in the rear, it will pull it. Wouldn't be my first choice, you'll be a lot happier with a little bigger motor.

You'll be a lot happier with a 8.3 - even better with a m11. I wouldn't turn down a 11.1 60 series detroit either.

 

[Delmer]

I don't know how far, or how fast you want to go. or how big of hills.

I wouldn't worry about the engine and trans much though. The HP will be set less than in a pickup, and you'll have a bigger radiator, so it's made to go 100% if it has to.

 

[soapstoneguy]

IMO the 5.9 cummins is just too small for a medium duty truck, unless it’s a light or low usage application (bucket truck, box truck, etc) They don’t have near the low end torque or engine braking that the larger displacement engines have. What transmission, rear axle/gearing does the truck have? If your terrain is fairly flat it may do ok, but I personally would pass.

I don't know the rear end. It's an automatic which isn't my first choice. Would like to find an f800 with an 8.3 but all the ones I have found are auto trans too...just really enjoy a nice 5 and 2.

 

[soapstoneguy]

Right now I tow that set up with a 5500 that has a 6.7 in it and it does fine, even up hills it usually pulls in 4th pretty well but I 'drive it like a grandpa' as most would say. I'm not big on running stuff 100% if I don't have to. I had a feeling the 5.9, since it is smaller than the 6.7 wouldn't pull it very well.
I sure appreciate everyone's input!

To me it just doesn't make sense to spend the money on something that can't act as a backup to the 5500 or a main hauler for the equipment. If anyone ever sees an 8.3 on a dump truck set up I'd be interested in it!

 

[soapstoneguy]

Truck is going to weigh, 12-14k? plus 16 of excavator, plus another 5-6k of trailer. 34-38,000 gross? If you have enough gears and low enough gearing in the rear, it will pull it. Wouldn't be my first choice, you'll be a lot happier with a little bigger motor.

You'll be a lot happier with a 8.3 - even better with a m11. I wouldn't turn down a 11.1 60 series detroit either.

Never even heard of the m11. What did they put those in?
I've tried to find a dt466 but sadly around here most guys still won't even touch them and a lot of the ones that pop up for sale someone has just beat to death which is a shame.

 

[soapstoneguy]

Also, side note. Anyone ever deal with a manual 5 and 2 but the high speed shifter won't work?

 

[BC Placer gold]

Also, side note. Anyone ever deal with a manual 5 and 2 but the high speed shifter won't work?

Check for power at the shifter, if power then probably seized up from lack of lubrication. We got a good used one at the wrecking yard and sealed it well to the diff housing. Works great now. Our truck is 6.6l/Allison 4sp, 2 speed diff. Slow but really low gearing, gets the job done. (Same truck as fc80)

 

[BC Placer gold]

On the flip side; we have another truck with a Cat C12/ 13speed, it is much nicer to drive and as a bonus it actually gets better fuel economy than the 6.6l ‘Brazilian’ in the Ford cabover- (2200-2600rpm)

Pro’s and con’s of each….

Really depends on your local driving conditions. In our case the smaller truck is really useful as a support vehicle for off-road/secondary highways. We have a lot of hills/mountains where we operate and the 4 way flashers get a fair bit of use…

For use on pavement I would try and find a larger engine if possible (like the 8.3, L10, M11 etc). Not really familiar with the newer stuff. Good luck!

 

[Old Growth]

There is a reason that DT466 trucks are run into the ground! They just keep running!

 

[MG84]

Any of the medium duty trucks you’re considering are going to feel very slow compared to a modern diesel pickup. The power to weight ratio is just a lot less, there’s just no way around that. However, aside from being slower on the hills, the medium duties will handle the load better, stop better and cost less per mile to operate.

I tow similar loads to what you are behind a 1988 F700 with the 7.8 new holland diesel and 5+2, and a 2000 IH 4700 with DT466 and Allison mt643. Both trucks are around 190hp and have air brakes and haul the loads without much fuss, but some of the really big hills will pull me down to 10mph when grossing 35-40k. Trucks like this there is no running them easy, in the hills you are at 100% max power all the time, but they are made for that. The truck with the Allison is nice to drive, but at slow speeds it gives very little engine braking, at highway speeds it’s fine. The truck with the 5+2 also seems to put more power to the ground.

 

[Truck Shop]

And there you have it.

 

[BC Placer gold]

Any of the medium duty trucks you’re considering are going to feel very slow compared to a modern diesel pickup. The power to weight ratio is just a lot less, there’s just no way around that. However, aside from being slower on the hills, the medium duties will handle the load better, stop better and cost less per mile to operate.

I tow similar loads to what you are behind a 1988 F700 with the 7.8 new holland diesel and 5+2, and a 2000 IH 4700 with DT466 and Allison mt643. Both trucks are around 190hp and have air brakes and haul the loads without much fuss, but some of the really big hills will pull me down to 10mph when grossing 35-40k. Trucks like this there is no running them easy, in the hills you are at 100% max power all the time, but they are made for that. The truck with the Allison is nice to drive, but at slow speeds it gives very little engine braking, at highway speeds it’s fine. The truck with the 5+2 also seems to put more power to the ground.

Said it a lot better than I could!

We also had a 7.8 Ford/new Holland; it went a lot better than our current 6.6 version (Turbo, no intercooler)

 

[soapstoneguy]

Awesome thank you all for the very detailed and informative knowledge, I sure appreciate it. I'm not concerned with speed as I know trucks aren't meant for that. It just always seemed funny to me that they'd put a 5.9 in a truck because I have a buddy who has a 2500 and 3500 with that engine and it is just hard for me to envision him pulling the same setup that I do with his pickups ha. Always been drawn to the older trucks as well since that stuff is usually easier to work on and isn't going to require anything special. We used to have a 97 t800 that was a great truck and had over 800k on the frame and about 30k on a rebuilt cat and it always ran great. But now just want a little 5yder for smaller projects.

Thanks again everyone!!

 

[gwhammy]

The 5.9 is real easy to bump power on. First thing would be an exhaust temp. It's amazing what some timing, fuel and higher governor speed does for them. 8.3 or mechanical dt would be my first choices but I had a tandem dump once with a 3208 cat that surprised me how good it pulled. I'm all for staying with the mechanical engines for simplicity and dependability.

 

[Tyler d4c]

Yet another case of trying to use a light duty engine for heavy duty work. Sure a 5.9 can be juiced to do it and it will not make 150000 turned up working its stones off. You need like stated a m11 or a c12.

Personally if I where in your shoes I'd want something 400 plus horses. I like to be to the top of the mountain first!

 

[cfherrman]

An engine can make good power on low displacement but the one thing I have noticed is for engine braking there is no replacement for displacement.