'06 GMC K2500 Buildup

[1stDeuce]

12/13/17 Update: I know Photobucket issues cause most of you not to be able to see the pictures. There IS a workaround for some browsers!! Search "photobucket hotlink fix". You'll see apps for Firefox and Chrome. If you're not using one of those two browsers, you need to start. Click the "install" button and voila, pictures show up!
Enjoy,
Chris


Well, I like reading build threads as much as the next guy, so I'm gonna start one of my own, both for your enjoyment (amusement?) and to serve as motivation for me to do a nice job with my mods!

So I recently bought an older Hallmark Ute 8.5 for my truck, in hopes that it would serve as a good way to show my parents around Colorado for a week this summer, and then I'll let them take it for a week or so on their own hopefully! Camper mods will show in a different thread...

My truck is an '06 GMC CC-SB Dmax Allison. Mods will be general suspension enhancements, comfort items, and a little preparedness equipment. No big lifts, power tunes, or crazy stuff for me, KISS!

Current state:
Torsion bars tweaked just a little
285 BFG A/T's on H2 wheels
Just added Air Lift bags to get the rear up off the overloads. Hoping for a better ride.

Upcoming projects:
Better in bed forward tie-downs for camper
Front receiver hitch (for a motorcycle carrier)
Front winch bumper (I have an 8274 that was on my ol' '96.)
Possible 1" rear blocks and a little more bar tweaking...
Make new Trans X-member that doesn't hang down. (Mine came pre-mashed...)
Good T-case skid ??
Fix rear G80 or put in an AAM Torsen diff.

Here's a pic of the rig for posterity...

Stay Tuned!!
Chris

 

[RU55ELL]

Looks like a good starting place. Is that a fleet truck?

 

[1stDeuce]

It's a "Work Truck - LS" GMC, which means no outside trim, rubber floor, but cloth seats, power windows, locks & mirrors, cruise, and some other features. Had gray steel wheels with literally shredded tires when I got it. It belonged to a grain company in N. Dakota I think. The underside is all gravel blasted, and the skidplates and trans crossmember are a little beat up too. The white hides dents and scratches, which it has a few of...
This is my second GMC with a rubber floor, and I will never go back to carpet in a truck! It's also the first automatic I've owned, but I knew from my last job that the Allison and I get along just fine.
Chris

 

[1stDeuce]

Air Bag Installation

This is a little after the fact, as I did the install last weekend, but I thought I'd put a quick summary out for the Air Lift airbags that I installed.

My truck didn't have an easy life before I got it, so the rear springs are very close to the overloads even with the truck empty. This means the truck doesn't squat much with you weight it down, but the ride isn't so good, since the overloads are always kicking, even with it's empty.

I decided to put air bags on to get a little height back, as well as to get the spring pack up off the overload leaf and hopefully improve the ride some.

Picked up a kit from Air Lift, as they're made in Michigan, where I'm from, and the price was a little better than the Firestone kit. (I had Firestones on my '96 and they worked well too. The kit for my '06 looks almost identical to the A-L kit I bought.)

Installation was just plain EZ. Unbolt and remove the factory jounce bumper, bolt together the bags and brackets per the instructions, leaving the top bracket loose. Jack up the back of the truck a little to get some working room, and put the bags with brackets in place. Two bolts top and bottom, and a little wiggling to get them set evenly away from the springs, vertical, plumb, etc, and then tighten the bolts down. I replaced the license plate screws with the air line fittings as is commonly done, plugged the lines into the fittings on the bags, added a few zip-ties and a heat shield on the tailpipe and I was done. I'd say it took me about 2 hours total from start to finish.

30psi is enough to pick the truck up off the overloads a little higher than it sits empty. I haven't had a chance to drive it yet, but based on experience with my last truck, it'll be nice.

I'll shoot a few pics tomorrow and post them.
Chris.

 

[locrwln]

Looking good. The 'Max/Alli combo is pretty amazing, even offroad.

Jack

 

[topofpalomar]

06 GMC Buildup

Chris:

I added a leveling kit along with a tweak in the torsion bars on my 2006 Chevy 2500 4X4 single cab Duramax/Allison. Got 3 additional inches on the front. Also got a one inch block in back with Firestone airbags. I haul an older Apache popup camper in the bed and it works great. Running 285 75 16 Toyo M-55 tires. Added the Bilstein 5150 shocks, too. No tire rub at all, even running some rough stuff in the desert. Rides rougher without the camper, tho. Mine's an LS trim level, too. Has a real, honest to goodness shift lever for the transfer case on the floor. Looks like you've got a great start for the rig. I'm subscribing and will be watching your progress.

Cliff

 

[1stDeuce]

Ok, a little more work done over the last few days... First, I wired up and in-bed RV connector so I can plug my camper in, and so my gooseneck wiring isn't hanging over the tailgate anymore. Kudos to GM on this one... On the HD trucks with a tow package, the wiring is already run to the front of the box, wrapped up and zip-tied in place!! All I had to do was drill a hole, feed the wires up through, and put a connector on. Took all of about an hour to do it right. There's even a sticker on the wire look that tells what each color does!

Here's the hole I drilled for it in the box side... I wanted to put it in the recess just rearward and a little higher, but I was afraid there wouldn't be enough room between it and the outside of the bed and I'd have a 2" hole with nothing in it... I think it'll be fine here.

After wiring up the connector, smearing a little rustoleum around the fresh hole, and screwing it into place, it looks right at home...

You'll also see that I put in another tie down just in front of the wheel well, on the bed side. That's so my camper battery can get lashed in like this:

Next thing I need to add are some HD floor tiedowns for the front of the camper. Looking for some removable ones like FWC used to use, but may just do two more U-bolts through the floor near the front where the cross rail is. With a little 1/8" plate to back them up, I'll pull the tie downs off the camper long before the U-bolts pull through the bed floor or the cross rail pulls off the bed!

 

[locrwln]

I just found the wiring for my camper yesterday when I was attempting to wire everything up for my new to me FWC. Gotta love having factory wiring ready to go. Did you install the 30 amp fuse under the hood in the stud #1 postion yet? I struggled with why the red 12v was not hot. Did a little searching and found out it needs the fuse to put power to that wire. All is well now.

Also, if you have a Fastenal near you, they have "nut" hook/loops in 3/8 and 1/2" sizes that all you have to do is drill up through the crossbed supports, run a bolt up through and tighten it down and you now have a very strong anchor point.

Jack

 

[olsen_karl]

Ok, a little more work done over the last few days... First, I wired up and in-bed RV connector so I can plug my camper in, and so my gooseneck wiring isn't hanging over the tailgate anymore. Kudos to GM on this one... On the HD trucks with a tow package, the wiring is already run to the front of the box, wrapped up and zip-tied in place!! All I had to do was drill a hole, feed the wires up through, and put a connector on. Took all of about an hour to do it right. There's even a sticker on the wire look that tells what each color does!

I had no idea that the tow package included that -- I'm going to have to take a look at my truck and see if that wiring is there too. I have a 2000 GMC Sierra 2500, with the HD option package (not a "2500HD" per se, but AFAIK, mechanically identical to the 2001 2500HD with the primary exception being the semi-floating vs. full-floating 14-bolt). Mine has a factory tow package according to the RPO codes.

Where was the factory wiring stowed on your truck? Zip-tied to the frame somewhere near the front of the box?

 

[1stDeuce]

Yeah, actually it's right above the frame rail between the box and cab if you have it.
Not really sure when it started, so you might not... ??
C

 

[1stDeuce]

Here are some airbag pics for you all to check out too... These are the Air Lift units. Firestone kit is very similar. No install shots, but it doesn't get much simpler. Took longer to assemble the units properly than to bolt them into the truck. A floor jack under the hitch is a must to get adequate clearance though.

I doubt the heat shield is really necessary, as there's lots of clearance to the exhaust on my truck, but I put it on anyway. The truck really does ride better empty with about 10-15psi in the bags. Picks up the rear about 1.5" too, which gets it off the overloads, and makes it look a little better IMO.
Now I'm realizing how soft my 150k mile OEM shocks are... Time to save up some more $$...
Chris

 

[bob91yj]

I work at a dealership, I'm fairly certain that all of the 2500/3500 HD's have the wiring harness for a 5th wheel 7 pin bundled at the cab/bed driver side. There may be the odd truck out there that doesn't have it. Seven pin 12v power does require connecting a wire at the fuse block, and installing a fuse. Trucks come equipped with a plug/play adapter for an electric trailer brake. If you have it, it's all taped together, usually with a 7pin/4pin adapter, and the 30A fuse. The brake controller adapter plugs in to the black box on the outboard side of the drivers footwell on all of the Dmax 01-07 Classic's, new body style has the wiring harness taped up under the dash.

A word to the wise, the 12v feature on the 'fridge in my camper will kill the truck batteries in a couple of hours...that is an ignition off 12v source. Ask me how I know this.

 

[olsen_karl]

Now I'm realizing how soft my 150k mile OEM shocks are... Time to save up some more $$...

Don't know if these are of interest to you, but I bought a set of Rancho RS5000 for my truck (came with old KYBs, at least one of which is blown & leaky) --

Summit Racing has them at $49 apiece, and there's a $50 rebate from Rancho right now.

Part numbers for my truck (may not be the same for yours):
http://www.summitracing.com/parts/R...r|2000|Make|GMC|Model|SIERRA+2500|Submodel|SL

http://www.summitracing.com/parts/RAN-RS5274/

Rebate form here:
http://www.gorancho.com/promotions.php

I happen to live near a Summit Racing store, and they mailed me a $25 off $100 coupon card too, so I used that. Shocks weren't in stock at the store, so they're shipping them to me.

From my past experience with Jeeps, Rancho 5000s are on the stiffer end of the spectrum of shocks. I wouldn't pick them for any lighter vehicles like Wranglers or Cherokees (Bilstein is my choice there), but I figure they won't be too stiff on a 3/4-ton truck with a camper on it.

 

[bfdiesel]

Why is the side of the frame cut out? I can't imagine that is good for strength.

 

[bob91yj]

GM didn't come out with a full length boxed frame until the 2011 model year.