My D-Max Build

[tmentzelo]

Now I know that many on here prefer Ford and Dodge and Toyota and and and...
But here it is:
2007 CCLB Silverado 2500 Diesel

I'm afraid to show how long the truck is... another day perhaps.

The purpose of this truck is to take me, my partner, and our motorbikes, to interesting places. We like camping in out of the way sites, and as all of you know, sometimes the best places are not so easy to get to. A truck camper is in the cards somewhere down the road.
I don't expect the truck to conquer anything more than a mildly Rugged Trail, and I'm more interested in a quiet and comfortable ride on gravel roads than anything else. I realize the issues the (really really) long wheelbase will create in any offroad situation, but I'm going to try it out...
There are many known issues with many components of this vehicle. I have so far addressed the transfer case pump rub (stock oil pump in t-case wears a hole :Wow1, pcv re-route, and a few other miscellaneous problems.

I decided to go with a 4"-6" lift from Cognito. It may not be as well known of a brand, but I've read some really great reviews, and after unpacking the components I'm impressed with the quality immediately.


Better than X-mas!




New Upper Control Arm

I have yet to get new wheels and tires, but I'm looking at something in the range of 33s or 34s on 17 or 18 inch rims. Many of the modded trucks you see up here in Alberta are sitting on shiny 20" rims and 12" lifts, but I'm not into that.
Much of my truck's steering components are worn from heavy towing for it's first 100,000kms, so out with the old and in with the new upgrades. I'm replacing most of the front end, and hope to detail much of the process.
I'll be tackling this project over the weekend and hope to post some new pics (and reasons for choosing a chev/gmc) soon!
Please feel free to criticize and illuminate, as this will be a learning experience for me and others.

 

[aardvarcus]

Nice truck!


I have a 2001 2500HD with the 8.1L/Allison. I love everything about it but the gas mileage. As far as wheels go, I took off my factory alcoa 16s and got the factory 17s off the 2007-2010 NNBS style trucks, so if you are going for stock-ish like me you might consider those. Even with the 8.1L though I was able to feel the acceleration penalty of switching from light wheels and tires to big heavy wheels and tires.


I fit 33's on my truck with no lift, trimming, or cranking so I would recommend you go bigger than 33 with a lift kit. I would keep it to 34 or 35 though. I would also recommend you not lift the truck with the kit more than the height of your front differential drop bracket. Typically a 4”-6” kit is more like a 4” kit but you can crank the torsion bars for extra height, which I wouldn't recommend. You want your CVs to be close to straight and you don't want your front end components to be at extreme angles. No sense wearing stuff out and making it ride rough, especially since you don't need that extra height for the size of tire you are wanting to run.


If you are looking for real world ground clearance, your lowest most vulnerable points will be your transmission cross member and your rear chunk. With your lift the transmission cross member won't be that big of an issue anymore, but your rear chunk will still hang low. Look around the offroading sites and you will see many examples of people shaving their 14 bolts, something to consider to net you some real world clearance in the back.


Be sure and post up what you do to your steering, mine could use some TLC.

 

[LovinPSDs]

I wanna get in and follow this thread, althought I do have a Ford. Looks like your on the right track with the truck, any plans for a winch and/or lockers? Maybe Hydro assist for the steering!?

Again I don't know about a Chevy, but on my Ford the shock connections and sway bars hang well below the axle tubes. Do ya'll do anything about this? I've been brainstorming on some ideas.

I love the idea of getting a big 1-ton in places it just doesn't deserve to be lol. Man I want to start building mine.... I have a wedding to pay for at the moment though.

 

[tmentzelo]

I was hoping to only to some mild power mods, as I would like to keep the drivetrain as reliable as I can. I also like how quiet the truck is on the highway, and am nervous that any exhaust/intake will cause a noticeable drone or too much intake noise.
I'm hoping the change in wheel size wont be as noticeable with the diesel, but if you are feeling it with the 8.1L engine I'm sure I will as well! I'm really looking for some used wheels and tires, as I want to see how they look and feel before deciding on an offset, width, etc.

I do plan on shaving down the 14 bolt rear end in the future, but for now time to bolt on some stuff!

The steering components I will be changing are as follows:
Pitman, Idler, and Pivot from Rare parts
Cognito Pitman and Idler support kit
Cognito Tie-Rods (these have some bad review all over the net unfortunately)

Things i've already done to the steering are:
New hydroboost and lines(old unit leaked and I still get some steering whine when braking and steering at same time),
New intermediate steering shaft (I went with an oem replacement, but I'm regretting that. It seems to have play in it again, and there is a nice (pricey) alternative.

I am looking at winch options, and bumper configurations. I'm really not sure what direction to take on this, as I want to maybe carry 1 motorbike on a front hitch and one on the rear (kinda silly I know).

This Duramax comes with a "locking" rear differential (5mph wheel spin engages a gear lock), but lots of people have complaints about it. It has worked well for me so far, but occasionally it refuses to lock up until I've dug a hole so deep on a hill that we cant get out of.
I really like the idea of ARB air lockers, but cost is high and I will probably leave that for the future.

Thanks for the feedback!

 

[bfdiesel]

I doubt you will notice much difference swapping the tires and wheels the 8.1 is much different than a turbo charged diesel. For power, reliabilty, and longevity mods delete the egr and the delete will require a tuner of some sort.

 

[Dirtysailor]

I have to ask about how you like your RTT, what make is it and what rack setup did you use to attach it to the truck. I am just getting into turning a similar truck into an expedition setup. First post in fact. I have been looking at a lot of builds and your is the first other duramax I have seen.

 

[locrwln]

They are great trucks and will go pretty much where they will fit. I hope that Cognito are using better upper control arm balljoints now, they went through some very bad versions.

You can read through my build up to see what and where I have taken mine. I do use a PPE Hot Race 2+ programmer set on the 90 horse mode for the mileage gain. I was averaging 17-17.5 mpg hwy before (stock) and have done as well as 20 mpg empty, but usually am in the 19ish range with it and that is with the 34" tall tires.

Gotta love a truck that you can do this:


Turn around and do an over 5k mile road trip:
(Camped along the Missouri River)


Get home and use it for this:


And still be a joy to drive.

Good luck on the build, I will be watching.

Jack

 

[tmentzelo]

Q&A

Hey bfdiesel,
I have ordered the cheap EGR block plate, though I should have just made one myself by the looks of it. One good thing about being up here in the cold north is that the LBZ (and other Dmaxes) may not require a tuner to deal with the EGR delete. Apparently, and after I install my plate I'll let you know, if you have the FE9 option code in the glove box you don't need a tuner for this.
I'd like a tuner down the road, but the cash isn't in the wallet for this at the moment.

Dirtysailor,
I have an ARB Pilbara RTT.
I built the rack out of a bunch of scrap metal and a headache rack that I built a number of years ago. The rack is really only a temporary thing, as I will bend some tubing in the near future for MKII.
I used to use a Yakima roof rack setup on my previous ride (Dodge 1500), and it worked but it really felt... Flexy. I think a Thule or Yakima setup is just fine though.
As for a tent review... I love it, but the Pilbara is a bit disappointing as far as build quality goes. We've spent over 100 nights up in our little "tree house," and it's comfortable but not all that convenient. I've treated the zippers with care, and I carefully set up and take down every time, but there is more wear and tear than I would hope for after 3 seasons of use. Thin spots in the tent canvas, broken teeth on the zipper cover, and a very tight fit to get the cover on securely have all annoyed me quite a bit. I notice the Eezi-Awn tents seem to have a better fitting cover, and people who own them are fanatical about how great they are, but there is the price to consider as well.

Jack,
Thanks for the post. I've been going through your build quite a bit lately. Very nice truck!

The latest version of the Cognito ball joints are supposed to be improved, but we shall see... I just liked the idea of an easily replaceable/servicable option for the front end of these trucks. I know lots of people hate the idea of IFS on a heavy truck, but I'm keen on seeing how well it stands up.

 

[Barry822]

Nice truck! Once you find the sweet spot your dmax should return excellent fuel mileage. Maybe even better once you delete the egr. I just drove to radium hot springs from edmonton. With less than 1000lbs in the bed I averaged 23.5mpg round trip. Coming home was up to 24.7mpg. Thats in a 2001 dmax with over 460,000km. Thats with the torsion bars slightly cranked running 285/70r17 on H2 wheels.

Sent from my SGH-I317M using Tapatalk 2

 

[tmentzelo]

T-Bars

I'm still waiting on shocks to arrive but I decided to tear into the job anyway. It's a long weekend and I work weekends so I'm guessing I wont need the truck.
I measured the torsion bar adjuster nuts, removed them with my overpriced t-bar loading tool, and started trying to slide them forward.
What was supposed to be a 15 minute job turned into an all day nightmare. The torsion bars had rust-welded themselves into the adjuster keys. I sprayed them down over and over with PB blaster, tried rigging up a few different pullers, hammered, HAMmered, HAMMERED!

Not even my Grandpa's old sledge made a difference.

The web is full of people experiencing the same issue, and the general consensus is to grab a bigger hammer, but working under jack stands its hard to swing said hammer.
From what I understand the t-bars are spring steel, and it's not a good idea to heat them up much. But the only thing I could think of to help get them off was the "big red wrench."

I aimed the flame the best I could at the adjuster key and any gaps between it and the t-bars, and enlisted the help of a friend to hold a ball peen hammer for me to strike with the sledge, and finally ding!
I was about to price out a new cross-member... Cant believe how stuck these things got.

What a waste of time!

 

[chilliwak]

Well at least you got the job done. Big congrats on keeping at it untill you got it right!:ylsmoke: Ow by the way, nice truck and welcome to the site....

 

[redthies]

Man, that frame is ruuust-e! Looks like my plow truck frame, but it is an '88! Makes me want to live in a warmer climate every time I think about it.

 

[tmentzelo]

Haha, redthies,
I should have made mention that frame the hammer is resting on is from a '71 chevy - another project on the go.
My Dmax frame is rusty, but not that bad...


The lift is taking more time then I thought possible.
Removing the pitman arm was a long process. Broken shock mount bolts, stripped crossmember bolts, you name it - I've had the mig out, the torch out, screw extractors.
I'm almost there. Tomorrow I will hopefully post photos of the finished 4" lift.

 

[bob91yj]

Cognito is good stuff, I think you'll be happy with it.

Mine is currently on a 6"RCD lift. Going to migrate over to Cognito stuff in the front.



There's a Jeep stuffed in the trailer, along with tools supplies.

 

[tmentzelo]

Nice truck bob91yj! What size wheels/tires are you running? Are those BFG Ats on there?

I've run into a bit of a hitch near the end of my 4" NTBD install:
I have a Pro-Comp torsion bar loading tool, and I can't crank on the keys enough to get the t-bar adjuster nut to slide in. The tbar tool is now bent from the effort of trying to load the bar enough to sit on the keys. It does look a little more "flimsy" than other large C-Clamp style tools on the net, but it worked just fine to load the keys and safely remove the nuts at the start of the install.
Should I really have to be cranking this hard to load the t-bars? I can't remember, but I don't think it took near this much effort at the beginning of the install to remove the bars...
I'm scared of breaking the tool and my ratchet taking out my teeth + face!
I'm wondering if the Non Torsion Drop brackets have changed the geometry of the tbar mounting some how? I don't really think it does.
Any ideas?