How much weight towed with a 98.5-01 Cummins dually?

BillyRyan · 03-23-2019, 08:27 PM

Obnoxious tires from previous owner 285/75/16
Trying to sell them as I type this

I read it was a mix of gear ratios, I’ll have to check. Cruising 70-75 I know the rpms are at about 2100 in 5th gear. I did get 19mpgs empty

Sean Marconette · 03-24-2019, 11:54 AM

Billy,
I just sold my 2002 3500 last year, a couple differences in my truck it was a 6 speed and had 4.11 gears and was a 2wd, same engine as yours. I had it for 10 years and pulled a heavy 48 ft LQ trailer. One of the first things I installed was an electric fuel pump to increase the lift pump pressure to 24 PSI, and installed a Edge Juice with Attitude tuner and a non restricted exhaust. The tuner in towing mode was like a different truck, and would pull hills without issue. Everything else was bone stock including the air filter. I bought it with 49K and sold it with 119K. Fuel mileage pulling the trailer was 12 MPG, no trailer 19 MPG.

Your lift pump pressure is too low, and if the VP is not damaged it could be. If the turbo is in good shape, I would invest the money in a tuner, before hard parts other than a pump to get the VP happy. I ran a Holley blue pump as the lift pump and adjusted the spring to increase the pressure. I replaced the Holley pump 2 times as it would start leaking fuel at the seal, but worked without issue and served the purpose to get fuel to to the VP.

Sean

BillyRyan · 03-24-2019, 02:15 PM

Thank you for the reply sir, the lift pump is aftermarket. It’s a fass lift pump and the vp44 was replace about a year ago I was told. Usually when cruising it’s about 20 from the lift. About 12-15 over big hills. I am looking into a tuner.

But it towed your 48ft pretty good?

Sean Marconette · 03-24-2019, 11:48 PM

Your welcome!
I never had an issue with pulling grades. Yes it pulled my 48' trailer without issue. I always ran stock size tires too. The tuner was like night and day on power output.

Sean

BillyRyan · 03-25-2019, 09:41 AM

Great, I did find out I have 3.55 gears. So I’ll look into swapping them to 4.10s and purchasing a programmer and go from there. Thanks again I appreciate it.

FED 387 · 03-25-2019, 09:54 AM

Depending on which DANA you have there is a a 373 available little more gear than the 355 but not as tall as a 410 you get a little more pulling power but fuel mileage doesn't get totally killed either

340Cuda · 03-25-2019, 08:08 PM

Quote:

Originally Posted by FED 387

Depending on which DANA you have there is a a 373 available little more gear than the 355 but not as tall as a 410 you get a little more pulling power but fuel mileage doesn't get totally killed either

I might be wrong but I think the 3.73 is for the rear end that replaced the Dana in the D3500 turcks. I think the brand is "American".

03-23-2019, 08:27 PM	#1
BillyRyan Junior Member Join Date: Apr 2015 Posts: 58 Likes: 13 Liked 55 Times in 13 Posts	Re: How much weight towed with a 98.5-01 Cummins dually? Obnoxious tires from previous owner 285/75/16 Trying to sell them as I type this I read it was a mix of gear ratios, I’ll have to check. Cruising 70-75 I know the rpms are at about 2100 in 5th gear. I did get 19mpgs empty Last edited by BillyRyan; 03-23-2019 at 08:30 PM.

03-24-2019, 11:54 AM	#2
Sean Marconette Senior Member Join Date: Mar 2006 Posts: 977 Likes: 794 Liked 275 Times in 76 Posts	Re: How much weight towed with a 98.5-01 Cummins dually? Billy, I just sold my 2002 3500 last year, a couple differences in my truck it was a 6 speed and had 4.11 gears and was a 2wd, same engine as yours. I had it for 10 years and pulled a heavy 48 ft LQ trailer. One of the first things I installed was an electric fuel pump to increase the lift pump pressure to 24 PSI, and installed a Edge Juice with Attitude tuner and a non restricted exhaust. The tuner in towing mode was like a different truck, and would pull hills without issue. Everything else was bone stock including the air filter. I bought it with 49K and sold it with 119K. Fuel mileage pulling the trailer was 12 MPG, no trailer 19 MPG. Your lift pump pressure is too low, and if the VP is not damaged it could be. If the turbo is in good shape, I would invest the money in a tuner, before hard parts other than a pump to get the VP happy. I ran a Holley blue pump as the lift pump and adjusted the spring to increase the pressure. I replaced the Holley pump 2 times as it would start leaking fuel at the seal, but worked without issue and served the purpose to get fuel to to the VP. Sean __________________ Sean Marconette 84 Mustang 5060 SS/N

03-24-2019, 02:15 PM	#3
BillyRyan Junior Member Join Date: Apr 2015 Posts: 58 Likes: 13 Liked 55 Times in 13 Posts	Re: How much weight towed with a 98.5-01 Cummins dually? Thank you for the reply sir, the lift pump is aftermarket. It’s a fass lift pump and the vp44 was replace about a year ago I was told. Usually when cruising it’s about 20 from the lift. About 12-15 over big hills. I am looking into a tuner. But it towed your 48ft pretty good?

03-24-2019, 11:48 PM	#4
Sean Marconette Senior Member Join Date: Mar 2006 Posts: 977 Likes: 794 Liked 275 Times in 76 Posts	Re: How much weight towed with a 98.5-01 Cummins dually? Your welcome! I never had an issue with pulling grades. Yes it pulled my 48' trailer without issue. I always ran stock size tires too. The tuner was like night and day on power output. Sean __________________ Sean Marconette 84 Mustang 5060 SS/N

03-25-2019, 09:41 AM	#5
BillyRyan Junior Member Join Date: Apr 2015 Posts: 58 Likes: 13 Liked 55 Times in 13 Posts	Re: How much weight towed with a 98.5-01 Cummins dually? Great, I did find out I have 3.55 gears. So I’ll look into swapping them to 4.10s and purchasing a programmer and go from there. Thanks again I appreciate it.

03-25-2019, 09:54 AM	#6
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,419 Likes: 528 Liked 332 Times in 180 Posts	Re: How much weight towed with a 98.5-01 Cummins dually? Depending on which DANA you have there is a a 373 available little more gear than the 355 but not as tall as a 410 you get a little more pulling power but fuel mileage doesn't get totally killed either