Tim Diehl II is a lifelong truck driver. The 40-year-old's spent the last 22 years of his life behind the wheel. His father boasts 50 years trucking himself -- the younger Diehl has known trucking his entire life.
Today, he hauls lumber as part of the family business, Southern Forest Products out of Mount Holly, North Carolina, and he's co-owner.
Tim Diehl IIPhotos and video by Lawson Rudisill
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The 1,000-hp rig is a welcome diversion from the doldrums he's seeing in the lumber business of late. It boomed during COVID, he said, when consumers were working from home and doing a lot of home improvement projects. Since then, things have slowed down for the family business.
“Right now, it’s slow, which is what everything is” in trucking, Diehl noted. Yet “all in all, it’s been a good business. If you have good customers and have a good relationship with people, you will always have a good business. And this lumber has treated us very, very well.”
Sagging demand isn't the only challenge moving lumber, particularly yellow pine, Diehl said. “That lumber is like ice” if you have to get on the brakes hard. “It’s hard to keep it tight. ... You can’t tighten it down enough where it’ll stay, I don’t care what anybody says.
“If you don’t know what you’re doing, you can end up hurting yourself and possibly somebody else,” Diehl added.
Diehl's 2003 Peterbilt 379 is shown here out the Large Cars event at Bristol Motor Speedway.
Diehl’s father bought the truck new and each of them put more than a million miles on the rig when it was still working. They pulled it off the road, though, rebuilding the 379 to give it as much power as possible.
The 2WS Cat C-15 under the hood has been totally reworked with “a very, very, very big turbo,” a different exhaust manifold, a bigger radiator and more that Diehl said he wanted “to keep kind of close to the heart about it.” The 18-speed Eaton Fuller transmission is turned around, which Diehl said “old-school people are gonna know what that means.”
All told, while not offering specifics, the truck puts out more than 1,000 horsepower and all the bigger engine components are there to ensure they can handle the extra power and torque.
“Honestly, I don’t know how fast it will really go,” he said. “I’m not trying to find out. I do know even at 17th gear, it’ll run over 100 mile an hour, and I still have one more gear to go.”
Outside the engine compartment, the truck is still mostly as it was when it was new. Diehl said many people who see it think it’s older than it really is. His style is to keep it old-school.
The rig's original interior, apart from a few added knobs and switches. "I'm just very, very old-school, and I want to keep it that way," he said.
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Tim Diehl II: I've done a lot of work through the motor in it. I won't say the exact number that it dyno'd on, but it's got over a thousand horsepower. That's what it's at right now.
I do know even in 17th gear, it'll run over 100 mile an hour, and I still have one more gear to go. It's a pretty nasty truck. It's hurt some people's feelings before.
Hey, my name is Tim Diehl. I'm 40 years old. I've been in trucking all my life. My dad's been doing it for 50 years. This is my 22nd. My mother owns a lumber yard, and we've been hauling lumber a lot the past 10 years. All in all, it's been a good business. If you have good customers and have a good relationship with people, you will always have a good business, and this lumber has treated us very, very well.
You can't tighten it down tight enough where it'll stay, I don't care what anybody says. So you got to stay on top of your game when you haul lumber. It's a it's a dangerous thing to haul. You don't know what you're doing, and you can end up hurting yourself and possibly somebody else.
Oh, this thing is a 2000 379 Peterbilt. We've had this truck since it was new. Ain't been but two people ever set their butt in the seat of this truck, and it's me and dad. He's put a million on it, and I have to. We redone this whole entire truck. I don't use it anymore. Now it's just a show truck.
I've done a lot of work to the motor in it. I won't say did the exact number that it dyno'd on, but it's got over a thousand horsepower. That's what it's at right now. It's a Cat C-15. It's a 2WS model motor. In my mind, that's the best model that they ever made.
You know, it's got a very, very, very big turbo on it. It's got a different exhaust manifold on it. We got a whole bigger radiator in it. It's got really, really, very big injectors in it. It's got 18-speed transmission in it; it's turned around. you know, It's got the biggest clutch we can put in it. Transmission has been done. Driveshaft is bigger. Everything from front to back to hold the horsepower and torque that it makes.
We race it a little bit just to play with it. I don't know how fast it will really go. I'm not trying to find out. I do know even in 17th gear, it'll run over 100 mile an hour so, and I still have one more gear to go.
I didn't want to do nothing to the inside of it. I'm very, very old school. I wanted to keep it the way it's always been. A lot of people thinks it's older than what it is, it still turns a lot of heads. I mean, it gets a very, very, a lot of attention.
It always smokes a lot too. I mean, just watch.
That's it, buddy. That's all of it right there. That's it.
