My New 03 1500HD
 

I thought I would share with you my new purchase, it is a 03 Silverado 1500HD LT 4x4, and I have a few mods in mind to help make it a little more me. here is a photo.

Re: My New 03 1500HD
 

I did have to sell my 03 Silverado 1500 LS 4x4 for it. Goodbye truck, i will miss you

Re: My New 03 1500HD
 

So, aside from the obvious reason (the HD sticker), I decided to upgrade (opinion) was that on weekends I am routinely towing 1 of several trailers ranging form 3000 lbs to 7500 lbs and I was always afraid of the 4l60e failing me when hooking up to somethin'. Also, I always seem to have a 3rd or 4th passenger. I went with the 1500HD because it has the LQ4, the 4l80e, 8600 lb towing capacity, but also 3.73 gears in the diff. So with the higher gears maybe it will get better mpg than the 2500HD my father has (14 mpg). From what I have driven on the interstate and highway it has proven to be true so far, but only time will tell.

The list of modifications will include, but are not limited to:

-Smoking the cab lights
-Remove the door trim (it is discoloring)
-Lifting the front 2" to level it out (and alignment)
-Intake (taken form the green truck before it sold)
-Tint the front windows (match the rear)
-Exhaust (stock 1500HD seems restrictive compared to 2500HD)
-HD Mirrors
-Custom Tune

Re: My New 03 1500HD
 

Nice truck. Maybe its just my truck but I think if you can get 14 mpg you are doing pretty good, the best I've seen out of mine (when it wasn't lifted) was 14 mpg. If you do the tune post some results if you don't mind.

Re: My New 03 1500HD
 

I got one that looks just like it, except it is 2wd and will be a 2000hd. Never heard of that? well the frame had a twist in it that we just could not get out on the frame rack and I bought another truck last week at the sale. It happened to be a 2500hd, the main diff I could tell was the rear frame section. I have both trucks so I know I will have enough parts to put the truck back right and still have a whole front left over to fix a 05 lwb Silverado out back that has been waiting in line. Oh another good thing is it leaves me a 6.0 4l80 maybe to put in on of my 70 project trucks??. Jim

Re: My New 03 1500HD
 

I dont think 14 is bad, I mean it is a truck and if I am concerned about mpg I should have got a Honda. My cousin has an 8.1L and he gets 8 mpg towing or not, but in the green truck I got rid of with the 5.3L I was getting 19 if I kept the speed below 70. I will post info on all mods and there effects.

I have never heard of a 2000HD, thats cool! It sounds like you wont run out parts any time soon, that is for sure.

Re: My New 03 1500HD
 

Nice truck, I have a thing for the 1500 HD's. The tune should help considerably with the mileage. My Dad's quadrasteer with 4.10's only gets around 10-11mpg.

Re: My New 03 1500HD
 

It might just be me, but I dont like the orange cab lights on the pewter truck, so I got ambitious on my lunch and smoked the lights. I took them off cleaned them and sprayed them with some VHT, I might spray them with some clear later depending on how shiny they come out. While waiting for the lights to dry I stripped off the trim because they were sun damaged and even though I do like the functionality of them it is cheaper to just be done with them. I used a pinstripe eraser wheel on a drill to remove the adhesive and if you get close you can see it needs to be waxed and buffed. I will get to the waxing later, but for an hour and a half of work I think it made a big change.

Re: My New 03 1500HD
 

Ouch! I thought about the quadrasteer, I found one for sale and everyone I know that has one loves it, but that mileage and the micro flared fenders makes me real glad I didn't go that rout.

Re: My New 03 1500HD
 

Getting my ride "On the Level"

I don't know why, but it really bothers me that the nose of this truck is so lo compared to the rear of the truck. The numbers on the corners of the truck from the ground the center of the fender lay out like this; RF=26.25", LF=26", RR=29, LR=28.5". So, no real continuity on the numbers but they are close and It is time to commit to turning some bolts.

Depending on who you talk to tightening up your torsion bars can either be a good or bad thing. On the good side it is an almost free (gotta get it aligned=$$) way to get the truck to sit the way allot of us think they should sit, bowing to no other truck! On the negative It does increase operating angles on the ball joints and that will inevitably make them wear out faster (faster is a relative term) and if you tighten up the bars too much alignment can get tricky!

My old 1500 had the bars cranked to the max (by the previous owner) and I ran that truck 100K miles after I got it with out a single problem and when I slid under the HD to look at my torsion bar situation the bars were barely turned at all. So to the jack and an 18mm wrench I ran. The bars under my truck are the GL bars with 8400 ft/lb torque rating and the second stiffest bar they put on Silverado trucks, which explains part of why the pork chop bolt is barely engaged and why it only took 5 turns to move the bar 1".

After turning the left 10 turns and the R 8 turns the truck now sits; RF=28", LF=28", RR=28.5", LR=28.5" (Turning the opposite side up more must have evened out the rear). These seem like figures that I can live with. I also had allot more room to tighten, but I don't want to push the angles on the ball joints too much. Also the alignment only cost $56 and it dialed right in on the specs I wanted, caster= 3.5* and camber= -.3*, it handles real good!

Article I found on the GM Full Size forum I referenced on Torsion bars, Keys and how to (interesting read and allot of info, weather you tighten the bars or not): http://www.gmfullsize.com/tech/torsion401.html

Before and after photos:

Re: My New 03 1500HD
 

better

Re: My New 03 1500HD
 

:metal: much better!

Re: My New 03 1500HD
 

Thanks guys!

Re: My New 03 1500HD
 

I like that truck. You are definitely headed the right way with it, too!

Re: My New 03 1500HD
 

Update time!

I have almost had this truck an entire month now and I have made several observations about this truck that I think are worth sharing.

1) In town I am getting 11.5 mpg and at interstate speeds 14.3 mpg.

2) There is a sweet spot between 68 and 69 mph where mileage goes up to almost 16.5.

3) The auto climate control in LT trucks robs my truck of about 2 mpg.

I installed the Spectre cold air intake I had from the previous truck (same part for both engines) and I have noticed some top end grunt, but not much of a mileage gain. I was afraid of installing the intake because on my 5.3 and on my dads 2500HD (he has a 03 6.0l) both droned in the cab bad at 2600-2800rpm but so far no drone.

Next I will be installing a Magnaflow muffler and tailpipe in Sept and I will report back.

Re: My New 03 1500HD
 

Well....some a$$ hat swiped my truck in the parking lot of Buffalo Wild Wings!!!! Thank God he is a moron because with witnesses watching he just backed out of the parking spot next to my spot and parked 150 feet from my truck, and went inside to eat dinner. When I came out to my truck a guy told me what the kid drove and then took me back inside and showed me who and where he was. So I approached him and we went outside and got all of his info and his ins is going to cover it. The worst part was I was throwing a bachelor party for a friend and I had about 17 guys that were more upset than I was at this guy. My friends didnt interfere but they were all standing around, I kinda feel bad for the kid he was close to crapping himself. Maybe next time he will leave his info on a vehicle he hits.

Re: My New 03 1500HD
 

I got the truck fixed from the parking lot incident. No pictures because it looks like an absolutely normal truck bed side. I have seen this shops work before and it has always been real good, but there is some trash in the paint or the clear coat, I cant tell. But it is allot better than it was so I am not worried.

I took my first real trip in the truck, about 1100 miles last week and the overall mileage for the trip was 14.4 mpg. It would have been better but 350 miles was up hill and into a Eastern Montana head wind that that netted me only 12.9 mpg. I averaged better mpg going over a 2500 ft elevation change mountain pass, go figure.

Lastly, when I bought the truck the driver side seat heater would turn on and quickly turn off and it is tarting to get cold here, so I did a search and found that it is a common issue. There are 3 problem issues in the system, the program in the seat needs to be updated or rebooted, the switch on the door goes bad and finally the elements them selves short out. I didnt think the program was the issue because the passenger seat worked and I doubted it was the switch on the door because the normal symptoms of that is the seats will turn on and off randomly, so I started with the elements. To inspect them I started tearing the drivers seat covers off and looking for any burns on the elements and I found the culprit!

Only 2 companies make a replacement part GM and Dorman. GM wants $175 for the part and through rock auto I had it shipped to me for $65. So, I tore off the old element and stuck the new one on (The part has adhesive strips). Looking at it I am impressed the truck didnt start on fire.

Re: My New 03 1500HD
 

Just replaced my muffler with little guy.

I have always wanted a Magnaflows kit and for the 6.0L there cat back kits are a dual 3 into a single 4". It seems ridiculous, I know, but they can back there numbers up with dyno stats and I dont have a dyno to disprove them so I will trust them. They want an arm and a leg for the kit ($650), so I Just bought the muffler for $160 and had a local shop order in a 4" pipe for about $100 and had them install it. The total bill came in right at $425 so piecing it together was way cheaper.

It sounds awesome, throttle response is quicker and you can feel a little more in the seat of the pants through the entire rpm range, especially mid range. The only issue I have with it is there is a light drone in the cab from 1300-1800 rpm, so putting around town can be annoying for passengers. I am gong to do some research and try and get rid of the drone, maybe neck it down to a 3.5" and see what happens. I will post any changes I make and any results I achieve.

Re: My New 03 1500HD
 

I just fell victim to the infamous "Pump Rub!" The pump in the transfer case rubbed a hole in the back half of T-case and almost all the fluid was gone when I found it.

Took it to the shop for them to rebuild for me and a few new bearings, bushings, clutch pack, rub correction kit, and a back half housing and it is as good as new. Glad I found it now as opposed to when I was fenders deep in a snow drift and 4wd didnt work because the T-case was smoked.

Re: My New 03 1500HD
 

You found it early. When we noticed it on our 04 2500hd, It was completely toast, no fluid, and started making one heck of a noise.

Re: My New 03 1500HD
 

69gmcc10, how many mile on your 1500HD? I have a 2003 1500HD with 82k miles. I've never heard of this problem, so I want to know when and how to watch for it. What do I watch for, fluid leaking from the back of T-case?
Thanks

Re: My New 03 1500HD
 

I have 150K on my truck. Talking with 4 different shops and doing some web searching all lead to the same conclusion, "eventually it will happen!" The thing to watch for is a shop that you trust to do the work as soon as you can afford to.

Here, a shop will charge $500 to take apart the T-case and install the pump upgrade and get you back on the road. Since I had some starvation issues and needed some more internal parts replaced and a new back half, because there was literally a hole in mine, it cost me just over $1000. If you dont catch it soon enough I was quoted $1700 for a rebuilt T-case.

Pump rub happens from the inside out so after the pump has trenched its way out like Bronson and McQueen in the great escape it is too late. $500 of prevention seems cheep compared to over triple for a whole new Transfer-case. You can save allot of $$ by doing it yourself because the pump upgrade is only about $120, I just didnt have the time to do it my self or I would have.

Re: My New 03 1500HD
 

Ive heard some trucks have it go out at 60k or 160k. The bad thing is, the hole is so small, on mine I didn't even see any fluid, none on the ground, none on the bottom of the truck, nothing. And you know what no oil does to moving parts that NEED oil.

Re: My New 03 1500HD
 

GM used a spring steel clip to try and prevent the problem but the clips are faulty. I am sure some of those sprigs will never break and others will break within a few miles. The problem is once that spring breaks the process starts and you dont know if that clip is broke or not until you get a hole or you take the T-case apart. My fathers 2500HD seems to be fine for now and it has 160K miles on it and my 1500 had no signs with 140k on it. I am just from the "ounce of prevention" school of thought and I would take a $500 bill over a potential $1500 bill and maybe even be stranded miles from civilization in a snowstorm with no 4wd to get me out of the ditch.

Re: My New 03 1500HD
 

may the wheel bearing and brake gods be with you.

Re: My New 03 1500HD
 

...and also with you!

quick update, the truck is running awesome, transfercase is getting used and working awesome in the snowy weather we have been getting.

Also picked up an 05 and newer GM truck e-fan for cheap. So, I got a wiring harness for it from ls1fans.com and since it was a black friday sale I also got a larger alternator jump box wire and alternator over drive pulley all for $100.

Re: My New 03 1500HD
 

Almost forgot! I got this little bad boy in the mail the other day and soon I will be mailing off my ECM to get my tune form Justin and the boys at Black Bear Performance!

Re: My New 03 1500HD
 

No picture of the ECM because it looks like any other ECM, but with a small black bear sticker on it. Initial report is that it is much faster and more powerful, time will tell on the MPG.

The entire process was simple, I hooked up my laptop to the truck using the cable and adapter box in the picture in post #26, took it for a 2 20 min drives and sent the info collected off to Black Bear Performance. They reviewed the data, told me to mail in my ECU (you can also be sent a new ecu so your truck has no down time, but I wanted to save $100) and they mailed it back all within 7 days.

They adjusted for tire size, removed the Engine Torque Management, reduced the Transmission Torque Management, slightly increased the shift firmness, shift points, set the ECM to run on 91 octane and I am sure they sprinkled some magic on it. It really made a big difference in drive-ability because the throttle response is quicker, downshifts are much more intuitive and when you want all the power and torque you paid for to be available to you when you want it, it is there.

What sucks now is knowing how much better it is and that every truck I own in the future must have its ECM tuned. Knowing how well Black Bear Performance treated me and happily answered my millions of questions I will certainly go back.

I will keep you posted on mileage in the coming months.

Re: My New 03 1500HD
 

So, it has been a while since I have updated this page.

To catch everyone up I replaced the cluster with a dorman unit. It has a lifetime warranty and works great. I went through summit and if i had to do it again I would go straight to dorman to try and speed up the time frame. Through summit the refund took a few days longer than I thought necessary.

I also got around to installing the electric fans they literally bolted right in a couple of existing threaded holes in the cross member and they work great! they are hardly ever on, but with the summer heat they keep my engine temp at a constant 200ish degrees. I have not noticed any significant increase in throttle response or mileage increases like some claim but I guess every little bit helps. The engine also gets up to temp quicker.

For MPG numbers after the fans, exhaust, Intake and most importantly the computer tune are as followed:
In town at varying speeds 13 mpg (up 2 mpg) is the norm, on the Highway at 65 mph it is around 18 mpg (up 4 mpg) and on the interstate at 75 mph it drops to about 16-17 mpg depending on the day (up 3 almost 3 mpg).

I am thoroughly impressed with the efficiency numbers and love everything about this truck.

Next project is to upgrade the trans cooler! on the 4th of July towing a toy hauler the trans got a little warmer than I am comfortable with pulling some of the mountain passes. I will post pictures when i get it done.

Pics of the fans and all the room it made under the hood.

Re: My New 03 1500HD
 

So...About that transmission temp issue.

One of the biggest reasons I sold the green truck and bought this truck was because I wanted the tough and robust 4L80E for towing heavier loads. I have been towing quite a few vehicles on my car hauler and a few utility trailers, but nothing over 6000 lbs, and truck seems to handle it just fine, but every time I tow over one of the passes (where I live I cant go more than 100 miles without needing to go over a pass) I would inevitably get some trans heat and see some numbers push 230 deg. Depending on who you talk to safe trans temps range from the high end of 240 to "you should never let your trans temp exceed 200," but regardless of max safe temps they all agree that cooler is better.

On the week surrounding the 4th of July the wife and I loaded up a toy hauler with a side by side and headed on a 6 hr drive to go camping. Over that week temps here were hot, hot for Montana (high 90's) and we had to go over 3 passes of about 2000 ft of elevation change. We were loaded right close to the max gcwr for the truck, not that the magical 14,000 lb number would have stopped me form adding more if needed, but I was not over. Trans temps ran high all day long and when we went over the passes it was getting hot! On the flats the trans temps didn't drop below 190 and on the passes even slowing down significantly to try and keep temps down it would climb to 240, not good.

So, I came to the forum under the Engine and Drivetrain section and started asking questions. I got some good answers and Clinebarger pointed me in the direction of the the Tru-Cool Max trans cooler as an upgrade to keep those temps down. It appears to be the answer to my problems so I ordered it up.

This cooler is big! It is 3x the size of the stock cooler and since I live in a place that can see some real cold temps at times I also got a trans cooler thermostat that bypasses the radiator until trans temps get up to 180ish.

Re: My New 03 1500HD
 

I have had the cooler on the truck for about a week now and I have been constantly checking the trans, it's temps and how the thermostat has been working. I have not pulled anything with it, but thanks to my handy-dandy temp gun everything seems to be running perfectly. The cooler came with almost everything I needed, hose, hose clams, brackets, adapters and bolts to mount it with. The parts that I elected to pick up were a pair of 3/8 transmission line quick connect adapters (stock replacement) that tread right into the cooler and connect to the existing trans lines and some black paint.

I lightly painted the Cooler black for 3 reasons, first it would look goofy to look through the grill and see raw a aluminum color, second to protect it from corrosion and finally the black helps dissipate heat. The black paint does insulate the cooler from transferring heat as air is drawn across it which is the coolers primary function, but it decreases that efficiency just slightly, hence the light coat to minimize those effects. Where the black paint helps is in radiation of heat sitting in traffic with little to no air flow and in this aspect it has a significant benefit.

I am not a huge fan of using rubber line and hose clamps, but it is the easiest, most economical and apparently acceptable to Tru-Cools standards way to connect the thermostat to the lines. I did use as little rubber hose as possible and flared all of the hard line ends to create as positive of a clamping location for the clamp as possible so I am satisfied with it.

I mounted the cooler in front of the rad and the a/c condenser with the original crossbar that mounts to the bottom of the stock trans cooler, I just turned the bar around so I had a flat surface to blot to and tapped into the latch support structure on the top.

Sorry, no pics of the thermostat, it is in a horrible location for a photo. It is installed in front of the forward cross member after it goes through the radiator to take advantage of the heat the radiator can provide the trans to prevent shifting issues on those cold winter days.

Did I mention this cooler is big!

Re: My New 03 1500HD
 

Talk about deja vu!!!!

My old truck... before
http://i196.photobucket.com/albums/a...ruck/012-1.jpg

after...
http://i196.photobucket.com/albums/a...all/image.jpeg

New truck...before
http://i196.photobucket.com/albums/a.../firstpic.jpeg

after...
http://i196.photobucket.com/albums/a...14_181604.jpeg

Re: My New 03 1500HD
 

Nice trucks, I am sorry to see the carnage on that x-cab. What are your plans for the HD?

Re: My New 03 1500HD
 

It has been a while since I have reported progress or follow ups on this truck so I figured I would update for anyone who is interested.

To start off, I needed to reapply the night shades after 1 year. I faded and wore off from the elements. When I reapplied it I clear coated over it to see if it would last longer and it has been better, but again the darkness is fading away but it might last 2 years.

I have a squeak up front from the lower control arm bushing and I think it was caused by me tightening up the torsion bars, but I am speculating. I have polly parts to replace them, but have not got around to replacing them yet. I also figured I would replace the ball joints while I was there, not because they are bad, but after 170K miles I may as well while I am there.

The oiled air filter sucks! I have always felt that these GM trucks live and die by the MAF sensor and the second it gets oily you can feel the performance decrease and see the mileage fall off, so I Replaced just the filter with an washable AFE Dry filter and it works real well. It has good mid and top end response and power from the system. I have another truck I using an AFE dry filters in the stock box and it is awesome! I would recommend only changing out the air filter and keeping the stock bock over a Intake system any day.

The 4" Magmaflow certainly moves the air, but it is raspy when you stand on the street and hear it drive by under throttle. It also has a drone around 1600 RPM that is annoying when sitting in the back seat. I have a 3.5" tailpipe I am going to change it out with and see if that helps.

The transfer-case is running flawlessly after the rebuild after the pump rub was discovered and repaired.

The Computer tune is still the most significant upgrade. Trans shifting and drivability make it worth it alone. Mileage has been good in the summer, city is still just over 13 mpg and I often get 18 mpg if I can keep it at 69 mph or below. In Missoula we are force fed Ethanol and when that happens my city mileage will drop to about 9 mpg and the best I can do on the highway is about 14 mpg. I hate winter Fuel.

The electric fans have have proven of little benefit fore economy if any, but the coll factor and the extra room under the hood is nice.

My other favorite mod after the computer has to be the Huge trans cooler I installed. My trans temps never get above 200* even pulling long steep grades at 7000 ft elevations in triple digit temps hauling 8,000 lb loads.

I upgraded the Shocks all around. KYBs in the front did not survive long after a raised the nose, too much travel. The fronts are Bilstines and they are perfect, they ride smooth handle holes in the road real well, and are the only shock that was made to work without a spacer for the shock on a torsion lifted truck. The rear is outfited with Monroe OESpectrum shocks and they are a big improvement over the KYBs they replaced, more robust parts than the kybs (i am told that is good for heat transfer) and more adaptive to changing terrain (KYBs would hop along in rhythm with washboards and concrete seams in the road, frustrating!)

Still, all in all, I love this truck does 90% of everything I need it to do and I don't think you can ask for more from a truck because if it was 100% of everything all the time it would be multiple vehicles.

Thanks for thanks for reading, I plan to continue to add to this as needs and time and money permit.

Re: My New 03 1500HD
 

old KYB shock, New side by side, and part number. I wanted to purchase Monroe Sens-a-Track but I think they changed the name to OESpectrum because the part number is the same. I have the Sens-a-Trac on my 69 GMC and I love those shocks as much as these!

Re: My New 03 1500HD
 

2 updates!

Ever since I installed the electric fans I have had an A/C issue that hasn't been a problem until recently. The problem is that on Max A/C the truck blows warm air through the vents because the second fan doesn't kick on. This hasn't been a problem until now because I don't usually run the A/C in town, I just cruse with the windows cracked, and when I do run it I am at speed down the highway where there is enough air running through the rad that the fans aren't on. The second fan does kick on when it needs the extra flow when sitting in traffic and the engine is real hot, but not when the A/C is cranked. So, I went back to the mechanical fan set up I kept because with a new child I definitely want to keep both him and the wife from screaming at me because it is so hot sitting in traffic.

I have noticed a little less off the line power, but everything else seems the same...except the Hydro Boost brakes seem to be more firm now and when coming to a stop the the rpms drop below 500 for about 1-2 seconds and pick back up. Go figure!

The other thing I did was get sick of the Bow-tie o the grill of my truck falling off so like a new Camaro Z/28 I grabbed a die grinder and cut out the emblem leaving the negative space behind as a black back drop. Glancing at it it just looks like black emblem.

Re: My New 03 1500HD
 

Nice thread. Which rear axle does a 1500HD get?

Re: My New 03 1500HD
 

1500HDs came with both 3.73 and 4.10, but like my truck, the overwhelming majority were 3.73.

Re: My New 03 1500HD
 

Thx, but I actually meant which axle not which ratio!

Re: My New 03 1500HD
 

Semi-float Corporate 14 bolt with lugs.