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The following is one way to move the front bumper forward on an 03 Chevy, for purposes of fitting larger tires. I opted to do this as opposed to trimming the lower air dam. I hope it makes sense, not all of the pictures I took came out, most were blurry. This is just how I did it, I took off the bumper not knowing what to expect, and this is what I came up with. PM me if you need clarification on anything.





03 Silverado front bumper move forward mod:


Overview:


The front bumper on the Chevy is attatched to a frame extention at 4 points, all near the "front" of the bumper, 2 on each side of where the license plate would be. In addition to these 4 main mounting points, there are 2 more of what I would call support mounts, 1 near each end, closer to the bottom of the bumper. I say support mounts because they are tubular support brackets, and provide no real impact transfer. These 2 support mounts bolt horizontal, that is the bracket bolts run from front of truck to rear. It is these brackets that allow the use of spacers, to move the bumper forward. The 4 remaining frame brackets have bumper flanges that "lay" on them, and the bolts run up and down through mounting holes. These holes must be redrilled, as moving the bumper forward no longer aligns the bolt holes. In summary what must be done, is spacers used on the support brackets determine how far the bumper is moved forward. Once the distance is decided, new holes are drilled in the frame brackets, bracket extentions are fabricated and the bumper is securely bolted in it's new position. It took me a weekend to do this, as it was trial and error, running to hardware store and bolt supplier, painting brackets, etc. With this info it "should" be able to be done in a day, but some trial and error will still be needed, as the bumper will have to be spaced according to your application.

Note:


If you choose to do this mod, do so at your own risk. Keep in mind you are moving your bumper, changing its mounting, all which can affect it's ability to do it's job in a collision. I did this mod last fall, and I no longer have some of the exact details (bolt sizes, bracket dimensions, etc, my apologies for the missing info).


Materials needed:


(1) 1 1/2" x 1/4" flat steel stock (came in 36" lengths at Lowes)
(1) 1 1/2" x 1/8" flat steel stock (came in 36" lengths at Lowes)
(2) 1 1/2" x 1/8" flat aluminum stock (came in 36" lengths at Lowes)
(6) Hardened Stainless Steel Bolts, lockwashers, nuts
Primer and Paint

Tools I used:


Reciprocating Saw (for cutting stock)
Bench Grinder
Drill
Dremel with carbide cutter
Wrenches/Sockets

Below is a picture of the steel and aluminum stock

Here is a picture of the Bolts used

The bolt on the left is the stock frame bolt, the one on the right is the stainless steel bolt. I went to a bolt supply company, and requested the strongest SS bolts they had. I forget what they were called, but they are made for strength, and not your usual hardware store bolts. Sorry but I don't remember the sizes.

Step 1 - Remove the Bumper:


Easy enough, no need to jack up the truck or anything like that. I used a creeper. My truck had the factory fog lamps, so first you must unplug the lights. Next locate the support brackets and unbolt them. Next unbolt the 4 frame bolts. You may need to access the top ones through the vent holes in the front of the bumper. Below are some pictures. Make sure you have someone to hold the bumper cause it will fall off (dropped mine twice).

The above picture is Post-Install, with the spacers in place.


You can see the mounting points above with the bumper removed. The upper bolts can be accessed through the bumper slots if necessary.

Closeup of support bracket where spacers will be added (above)

Step 2 - Fabricate Spacers and Drill New Holes

Now you should take your aluminum stock, and beging cutting it to make the spacers. I measured the appoximate size of the bracket face in the photo above, and cut the stock to the same lengths. Since the aluminum is 1/8" thick, it allows you to vary your movement in 1/8" increments, simply by adding or removing individual spacers. Place one of the spacers on the bracket and mark the hole location, then drill the appropriate holes into all of the spacers. Below is a photo of the spacers after cutting and drilling.


Now what I did is taped the spacers onto the bracket (so they would not fall off), and test fit the bumper. The top bumper brackets will rest on top of the top frame extension brackets and it will sit there, but be careful, it will fall off very easily. You can run your new bolt throught he spacers and hold it in place. This will be easier with 2 people. This is where a lot of trial and error in spacer amount is needed for your tires. I believe I ended up using 8 spacers (actually a little more than an inch). Also measure it several times at various points so it does not end up crooked.

That was the easy part, now it got a little complicated. By moving the bumper forward, you run into 2 problems with the remaining brackets. The first is obviously the holes no longer line up. The holes are elongated for left to right adjustment, but not front to rear. And by moving the bumper, the holes in the upper brackets are no longer able to bite into the upper frame extention, as it puts the upper bumper bracket hole at the edge of the upper frame extention, possibly not allowing you to drill a new hole, hence the need for extentions to be fabricated. Hopefully the below photo's will help it make sense. Unfortunately none of the frame extention drilling/notching mod photos turned out.

This first photo is of the back of the bumper, showing the brackets that mate to the frame extention brackets, and the support bracket on lower right.



These Photos are a closeup of the frame extention brackets, and where they will need to be drilled.



Determining where to drill the holes for the lower bracket is a matter of marking the hole location after determining your spacer amount and test fitting the bumper. You can also mark the upper bracket at this time but depending on how much you moved it, you may not be able to cleanly drill a new hole. Mark hole locations and remove the bumper. You can now drill the lower holes for your new bolts if you wish. The upper brackets now need to be fabricated. Some may question the need to make bracket extentions, since you'll have the lower bolts holding. But what I found is as you tighten the lower bolts, the bumper tilts forward as the bracket is pulled tight. You need the upper bolts to keep the bumper from being misaligned.

Step 3 - Bracket Extension fab

This is going to be a little hard to explain. As the bumper is moved forward, the edge of the upper bracket ends up right over the oem hole in the upper frame extension. This frame extension has a welded nut on the underside and is threaded, so the stock bolt just tightened down. I wanted to use this oem hole and integrated nut, so you need to notch the edge of the bumper bracket. I used my dremel with a carbide cutting bit to do this. See the photos below.

This first photo is of the frame extention, showing the lower hole drilled, and an outline of where the upper bumper bracket will end up, explaining why it will need to be notched. You can also see the outline of the bracket hole, and how it is at the edge of the frame extention.


This next photo is of the bumper bracket, showing the notch put in it.


I do not have a photo of the notch I put in the upper frame extension, but I also used my dremel to do it. You should have already marked your location in an earlier step. What I chose to do is use 1/4" stock to create a "bridge" that both the bracket and extention can be bolted to. The bumper bracket is 1/8" steel, so I used the 1/8" stock to make a spacer so the bridge could be bolted flat. You have two set hole locations, one in the frame extension and one in the bracket, so measuring is straightforward. I cut the 1/4" stock to an approximate length, placed the bumper back onto it's temporary position, and marked the first hole, making sure the stock was long enough to bridge over both components. I then drilled the first hole, put it on, marked and drilled the second hole. I then measured how large the 1/8" spacer needed to be and cut and notched that. All components were primed and painted. See the below pictures to hopefully further explain.

This first photo is of the 1/4" stock and 1/8" stock when originally sized and cut, making the "bridge".


This next photo is of the spacer and bridge after being drilled, notched, and painted.


Below is the bridge and spacer in place resting on the frame extension. The spacer is notched so it rests against the bolt. The bumper bracket is notched and will mate with the spacer against the bolt as it slides under the bridge. The bridge is then bolted to the frame extension and bolted to the bumper bracket, making a solid mount.


One issue you may run into is the bolt holes are only an inch apart, so gettng a wrench on the end of the bolts may be difficult. I also had to flatten one end of the washers to get them to sit next to eachother. Getting a wrench on the front bolt nut won't be fun either, you 'll see what I mean. Also, if you can weld the spacer and bridge together, do so. Or use epoxy or something to glue the two together so the spacer doesn't wiggle out. Speaking from experience.


Step 4 - Final Mounting

Now that you have fabricated the bridge, you can put the bumper back on. Loosely mount the bumper, as you will have to tighten all the bolts slowly together. If you tighten any of the bolts straight away the bumper will get crooked. You have to tighten, measure, tighten, measure. I had to back the bolts off several times and try different tightening sequences to get it right. The bumper brackets are not tight against the frame extensions, they have to be pulled tight as you torque the bolts down. That caused the bumper to want to move as I put the final turn on the bolt. Measure and make sure you have the holes in the right places, because your not going to have much wiggle room. Not to say you cant have good results, mine is very straight. Below is a picture of the bumper on, and the first bolt being started in the bridge. Photo is taken through slot in bumper.


Below is a finished photo showing the moved bumper. You can see a small gap at the rear of the bumper plastic if you look close. The second photo shows the H2 tire clearance. 34'5" Tire, does not rub under any circumstances.



Well thats it. That's how I did it. You may think I'm nuts, or made this too complicated. I am and I did. But it worked for me. Good Luck.

Mike
 

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I did the same thing (nearly) some time ago. I moved mine out 3.25". Instead of the stacked plates in your first pic I used a pipe cut to the right length. I have 35" tires one and I still trimmed the air dam due to the future use on chains on the tires. . . .


good pics!
 

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I'm about to have a go at it. I'll take pics to show.


-Chad-
 

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Well, here's my progress so far. I got a late start so I'll finish up tomorrow.











Here's a pic of the front end. i took off the grill shell just for safety measures. I also have my spacers installed.





well, wish me luck. I think I got my self in a little deeper then I would have like to, but the end product should be nice.


-Chad-Edited by: allstok03Dmax
 
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