Re: Hatzies 2005 2500HD
 

Nice looking truck!

Re: Hatzies 2005 2500HD
 

I replaced the plugs and wires around the same time as I did the fluids but I didn't comment on it.

NOTE: If the heat shields are rusted away the replacement is ACDELCO 8006 and aftermarket options exist. Mine were fine so I re-used them.

There are supposedly two different coils used on the LQ4 truck engines with differing output terminal position and different length plug wires.

Delphi XS10389 10.5in wires for Coils Stamped 12558693 "Square coil"
Delphi XS10388 9.2in wires for Coils Stamped 19005218 "Round coil"

I use dielectric grease inside the boots on both ends so the wires will actually come off the plugs next time I do them.
The original plugs were the now obsolete AC Delco 41-985 Platinum plugs... Why not use the 41-110 Iridium plugs that are shown as replacements a lot of places?

I wanted to avoid the rumored idling problems and fuel mileage issues that are blamed on the 41-110 plugs.
She idles smooth and gets around 13-14mpg hwy on the new plugs and wires as opposed to the 10-11mpg and slightly rough idle I was getting on the old plugs and wires so I'm happy.

I use Never Seize in the threads. Be exceedingly careful to not get this on the electrodes or past the threaded section of the plugs. I apply it with a plumbers acid brush rather than the slop brush in the bottle to keep it confined to the threads. It's conductive so it'll make trouble if it gets on the ceramic or in the plug boot.

Service bulletin on the spark plugs...

Bulletin Number: 13D-070
Date: May 21, 2013
To: DDG Headquarters and Branches
Category: Product
From: Brad Brunken, Product Development Line(s): 41

Subject: ACDelco Spark Plugs 41-110 and 41-962 - Application Update

Description
ACDelco announces that 2006 and older, as well as some 2007, spark plug service applications
covered by the iridium spark plug 41-110 have moved to the platinum plug 41-962. For the
older model years, GM used a double platinum spark plug in production, and these older
applications are to be serviced with the double platinum plug 41-962. 2007 and newer
applications used iridium plugs in production and service requirements will remain assigned to
the iridium plug 41-110. Both plugs meet original equipment specifications for the applications
designated. Catalog changes for the Epicor and WHI systems will be updated in the June
release 2013. ACDelco recommends you begin adjusting your stocking requirements for the
41-962 in preparation of the upcoming catalog updates. The estimated sales volume split
between the two spark plugs is 50/50 based on these application changes and vehicles in your
markets.

Aiming the headlamps
 

Brand new headlamps are not aimed properly. One of mine was setup for squirrel hunting in the trees.

The adjustment method in the video works very well.
I would recommend doing this after dark.

You need;

• I've forgotten the exact size... external Torx socket (I needed an unknown E-Torx size to pull the seats so I bought a set that included E4 through E22 with some gaps)
• Two inch wide blue painters tape
• Sharpie
• Yardstick to mark centreline on the tape on the door
• Thirty foot measuring tape.
• 5 or 6 gal bucket filled with sand
• Four or five foot landscaping stake

I put a landscaping stake in a bucket of sand at 25ft from the garage door I was using and backed the truck up til the corner of the front bumper was even with the stake.

I'll add a picture HERE of the centre mark on my GM headlamps.

Unfortunately the optical centre mark on my headlamp lens does not show up in pictures taken with my camera.
You're looking for a mark that looks like the Greek letter Theta θ near the horizontal centerline of the lens on the LO-Beam side toward the HI-Beam and LO-Beam reflector divider.

Re: Hatzies 2005 2500HD
 

Very nice truck. I think damn near every 03-07 I come across is the Silver Birch color (oir black). Makes me wonder if any were painted a different color :lol:

My new to me 06 is Silver Birch too. :rolleyes:

Re: Hatzies 2005 2500HD
 

There are a lot of them.
If I need body panels I don't have to paint em...:lol::lol::lol:

Re: Hatzies 2005 2500HD
 

Very True, never thought of that! :metal:

Re: Hatzies 2005 2500HD
 

The speedometer has been slightly off since I bought the truck.
It came with 285/70R17 32.7" tires on Hummer H2 wheels that rubbed when I made tight turns. Those 33s are too big without a suspension lift and spacers... that ain't gonna happen.

I installed N89 17x7 wheels with Michelin Defender LT 265/70R17 Load Range E tires on the truck in September. Those tires are 31.6" diameter according to Michelin.

The stock tire size is 245/75R16, 30.5", on PY0 wheels. The additional 1.1" of tire diameter throws off the speedometer and ABS computer.

This is a two step process with two different pieces of hardware. I used a Tech 2 and a HP Tuners to do this. You could do a PCM tire size update via GM techline using the Tech 2 or MDI if the tires are an approved size. My tires are not GM approved.

I updated the tire size in the ABS controller using my Tech 2 back in September. 265/70R17 is not an available tire size so I set it to 265/75R16... they're both 31.6" outside diameter.
The brakes seemed to behave better after just the ABS change but that could be my imagination... I never trust the butt dyno... even a finely tuned instrument like mine :lol::lol:

Unfortunately the ABS parameter change doesn't update the PCM (ECM/TCM) tire size on this truck. The speedometer was still reading several MPH lower than my GPS. That's definitely the wrong direction for this kind of error.

I have HP Tuners MPV2 registered to my Impala SS so I bought two Universal Credits and registered the 2005 Silverado to my MPV2 so I can modify parameters like the tire size.

I read the contents of the PCM and saved an un-molested copy to my laptop HDD and a thumb drive I keep in my garage laptop bag so I can go back to the as-shipped settings if I screw up. I have an otherwise un-molested copy with the modified tire sizes as well.

HP Tuners can't make changes to the ABS controller parameters so you need to make changes to that with a Tech 2.

Having the correct tire size in the PCM puts the fuel maps, transmission shift points, and TCC engagement back to the as-delivered from GM behavior. Fuel mileage has jumped noticeably and it no longer feels like I'm pushing it hard to go 65 on the highway.

After the PCM tire size change I see 32 on my GPS with 35 on the needle, 54 on my GPS with 55 on the needle, and 73 on my GPS with 75 on the needle. The rest of my cars and trucks read between 2 & 3 mph higher on the needle than the displayed GPS speed so this is well within what I would consider "normal" operation.
The odometer reads 1 mile in a measured mile so I'd call that good to go as well.

Not sure if I'll make any changes to firm up the mushy TCC and 4th gear engagement now or not. I'm going to drive it a little to see if this change alone made enough difference to make me happy.

It's worth noting that the chime replacer for the aftermarket radio can interfere with the Tech 2 and HP Tuners communication through the J1962 port. If you can't read the PCM unplug the radio harness and try again.
I'm going to experiment with putting a key switch to shut off the Class II data wires to the chime replacer when the weather gets warmer. Opening the dash to unplug the radio when I want to make changes to the PCM is a PITA.
If a switch in the data lines works I'll make a howto post... Honestly if the chime replacer was properly setup it wouldn't interfere with the Class II databus communications but these are built to a price point and proper engineering costs money.

Re: Hatzies 2005 2500HD
 

Sure is a nice truck

I'm sure that you're aware, but just a reminder. Have you done the pump rub kit for the tcase yet? I got about 230K miles out of mine before it rub'd a hole followed up by several holes around 300K miles. It eventually took out the tcase one day from a lack of oil.

Re: Hatzies 2005 2500HD
 

Change the tire size in the PCM with HP Tuners. While you're in there firm up the shifts, shorten the shift times, change the PE delay, EQ ratio, copy your high VE table to the low VE table.

If you want to see a noticeable gain with out a ton of internal mods, get the 4 bolt intake (08 - and newer) with a LS3 throttle body. 20-25hp easily noticeable gains from that alone on 91 octane.

Re: Hatzies 2005 2500HD
 

This is not something I want to tackle til April or May... with only @ 87,000 miles on the clock it's not super pressing to get it done when I'd be working on cold hard concrete at 0°to16°F in the unheated barn.

There are a couple pump housing replacements that are supposed to eliminate this issue on the NP263HD. I'm leaning toward the Merchant Automotive pump housing. I'm going to reseal the whole case while it's apart including the internal o-rings like the oil pump pickup tube o-ring. A lot of the howto videos make me cringe when I see them re-installing the oil pump pickup with the old o-ring.

Re: Hatzies 2005 2500HD
 

I'm reading up on how to make the shifting a little less mushy. I'd like to do it without shock loading and breaking internal parts when I've loaded the bed up or I'm towing. If re-programing it will not make it last longer and run cooler then it's not worth doing.

I already have two 91 octane cars, the Polara and the Impala, and the FE390 in my F250 that will likely need 91 or at least 89 to not knock like I have maracas under the hood. I like the fact that the LQ4 runs reliably on 87 octane with power levels on par with the 383 Big Block Chrysler in my Polara. I may eventually get the itch to play with it but not right now.

Re: Hatzies 2005 2500HD
 

With your stock engine, you will have zero issues with "shocking" the trans. You can copy over the line pressure setting from the tow-haul or performance tables to the normal tables.
If you're wanting to make the trans run cooler, shorten the shift timing, and add an inline trans cooler like a Tru-Cool Max 40GRW.
If you ever feel a laggy 1st gear start after coming to a stop. There's a fix for that, and TransGo sells a piston replacement kit for it.

Re: Hatzies 2005 2500HD
 

I used the same Merchant Auto kit on my replacement tcase and it was painless. I bought everything from them as a kit.The hardest part was pulling and installing the TCase while as you said, on the cold concrete. I spent some time getting all of the original RTV out of the case along with the sludge build up around the filter area.

Re: Hatzies 2005 2500HD
 

I can just push the tow-haul button to get that. I want to put some miles on it to see if the original GM settings are too sloppy for my taste with the proper tire sizes in the PCM now.

Already have the Tru Cool 40K plate cooler mounts along with the Delco Jiffy-Tite transmission line adapters. Just need to put it in.

1st gear in my 4L80 is still pretty tight right now.

That's the direction I'm leaning on the kits. It'll be nice to clean the crud out of the bottom of the case too. The Howto videos show removing the magnet and replacing it with a smaller one on the drain plugs... Not a good idea IMHO. It looks like it's the same big Allison filter donut magnet GM called for in the 4T65E and 4L60E transmission magnet TSB. The Allison magnet is rated for more than 300°F with a lot of surface area to pick up iron particles from the silent chain... that's probably what I have in my NP263HD so it's staying after a good cleanup.

Re: Hatzies 2005 2500HD
 

Yep you can do that if you want, but the shift points are much more delayed, and there's more engine braking with the tow haul turned on.

Get that tranny cooler in and you'll see the difference instantly.

Re: Hatzies 2005 2500HD
 

That's a better explanation than I've found before of what else tow-haul does.

Thanks...

Re: Hatzies 2005 2500HD
 

Yep, dont forget to use the compare feature when comparing other tune files

Re: Hatzies 2005 2500HD
 

Drove to Dedham and back today.
Recorded the fuel mileage on this trip with the correct tire sizes in the PCM and ABS controller and no other changes.
4.10 gears and 265/70R17 Load Range E tires at 50PSI.
223 highway miles from last fill.
15.78 gallons to fill the tank.
223 ÷ 15.78 = 14.13MPG calculated.:metal:
Instrument cluster says 12.8MPG.:lol:

This should change with the tracked MPG info...

Hatzies 2005 2500HD fuel mileage

The transmission still takes a while to slide in and out of 3rd and 4th gears. Kinda like riding the clutch. If it ain't good for a standard clutch I can't see where it would be good for an auto either. I have a tune with the tow-haul pressure table copied to the normal table along with the shorter shift times from the tow haul mode table.
If that doesn't get rid of or at least minimize that sliding feel I'll look into how I can go about shortening the TCC engagement timing without slamming it home every time it engages.

Re: Hatzies 2005 2500HD
 

Before I changed anything in my PCM I captured a "right now" PCM image using the HP Tuners VCM Editor.

I then programmed it to purely stock GM settings using my Tech 2, and a single VIN AC-Delco TDS Service Programming subscription.
The HP Tuners compare function of the "Right Now" and the after TDS programmed images shows it was bone stock but it is 15 years old and I couldn't know for sure.
Account setup is free but you have to pay for Service Programming access... as of this writing Feb 2, 2019 the cost is $40 for 24 months single VIN Service Programming.
https://www.acdelcotds.com/acdelco/action/home

The Tech 2 requires a good quality RS232 serial connection. No device drivers needed in Windows 7. BTW DO NOT USE a USB to Serial adapter for service programming... the USB to RS232 device drivers cause signal latency issues so you could easily brick the PCM. I used a Quatech Expresscard-34 EXP34-SSPXP-100 (PCI-e) RS232 adapter in my old HP8560W Mobile Workstation.

This is the procedure for calibration updates with a Tech 2 in J2534 passthrough mode.

The same with an MDI.

This is a YouTube video of the procedure using a VXDiag Chinese J2534 passthrough tool. I'm leery of anything from China that requires me to install Chinese device drivers. A tool like this is no exception. IMHO A Tech2 or MDI is a safer choice.

I should've put this further back in the thread but I didn't have a good howto til I found this video group from Dr Shock.

If you don't have a laptop with a good Serial port... The WiFi MDI clones are pretty decent quality now. Get the high quality unit with the SQU WiFi card and load it using the MDI manager from Bosch... not the one that comes from China on CD. MDI manager straight from Bosch has un-molested drivers.

You can use the hacked version of Tech2Win that ships with the clone MDI but the Tech 2 is lighter than a laptop and runs from the vehicle battery. The Tech2 will also talk to 1992-1994 ALDL and 1995 OBD1 vehicles. The downside is the Tech 2 costs more than the MDI and only supports vehicles up to around 2009 or 2010 with limited support for 2011-13.
The Linear flash card image BIN files that the SAAB guys put up on the Tech2WiKi will work with the MDI and Tech2Win on 1996 and newer vehicles.
I have both a Clone WiFi MDI and a Tech 2. I just bought the MDI. I've had the Tech2 for several years.

Re: Hatzies 2005 2500HD
 

Added more info to the programming post.

Re: Hatzies 2005 2500HD
 

Added tailgate soft-open assist strut so the tailgate won't slam open.
Dee Zee DZ43100


http://johnnynightstick.s3.amazonaws...217_161140.jpg

http://johnnynightstick.s3.amazonaws...217_161127.jpg

Re: Hatzies 2005 2500HD
 

Very interesting reading I chenged my tire size from 245 to 265 on my 04 2500 HD and my brake pedal has a somewhat mushy feel to it wondering if this is in relation to tire change or problem with the hydro boost brake system. Truck only has 62,000 miles

Re: Hatzies 2005 2500HD
 

Not sure what all the ABS computer does to the braking outside of panic stops but anecdotally it seems that it may make more of a difference than I thought several years ago.

The mushy pedal is an interesting observation. Mine felt mushy as well and it seemed to be firmer after I set the tire size in the ABS module. I figured it was my subjective opinion at best... but reading that someone else has the same thoughts on the braking begs some questions.

I'd be very interested to know what your subjective opinion is on the change in braking feel after making the tire size change in the ABS controller.

If you have a tool to change the tire size in the PCM I'd be very interested in hearing how that change affects your drive feel as well.

IMHO It will not hurt a thing to flush the old DOT3 fluid out of the brakes with fresh clean DOT3 or DOT4 and change the power steering fluid. Both are likely the stuff that the GM line workers put in your truck on the assembly line. My brake fluid was blacker than pitch and the power steering fluid was not any better. The brake fluid is already getting dark again so I'll flush it out again when the weather improves... probably the power steering as well since the the Hydroboost brake assist is run off the power steering fluid.

You can't change the ABS module tire settings without a Tech 2 or MDI or equivalent with Tech2Win on a laptop. When you get to the ABS tire size change menu in the Tech 2 you're looking for a tire size that's the same OD and similar width. My 31.6" 265/70R17 tires weren't in the list but 31.64" 265/75R16 were. Same 31.6" OD and same 265mm section width. 0.04" difference in diameter is close enough... 638 tire revolutions per mile.

Use the comparison calculator tab on this page to see what difference a change in tire diameter, width, circumference, revs/mile, etc makes.
https://tiresize.com/calculator/

Re: Hatzies 2005 2500HD
 

That's a great looking truck.

Finding info on the 99-06 trucks can be quite challenging.

Thanks for the little details on your build, really helps down here in Australia.

Cheers Mark

Re: Hatzies 2005 2500HD
 

I've updated the speakers the way I wanted to do it. If you prefer a different method add it to your build thread.

My truck has the "Enhanced" UQ3 uplevel six speaker option. Woofer and tweeter in the front doors and Speakers in the rear doors. I would guess the enhanced is the tweeters with the Capacitor that probably acts as a rudimentary crossover.

I have an inexpensive Kenwood KMM-BT522HD head unit. It sounds fine and it didn't require cutting up the dash support to fit a deeper than stock head unit.

I kept the steering wheel controls and the warning chimes with a Crux CS-GMC2.
NOTE: This module seems to interfere with writing updated configurations to the PCM through the J1962 port (OBD II). Modules that don't interfere may exist... however the first question asked in communications issues threads is "Do you have an aftermarket radio or chime replacement unit connected to the Class II databus." Unplugging the factory radio plug from the aftermarket hardware fixed my comm issues.
I have zero issues running bi-directional diagnostics with my Tech 2 or my MDI with Tech2Win so this may be an interaction between HP Tuners and the Chime module.

After 15 years the speakers are showing their age.

I decided to look into better speakers. Infinity and others require mods to the door panels. I decided I didn't want to do that.

The UQ7 Bose speakers are a drop in with the exception of the tweeters... Bose tweeters were mounted in the A pillars the UQ3 tweeters are bolted through the front door cards behind the speaker grilles. They're both high audio frequency speakers. I chose to keep the UQ3 tweeters rather than run wires to the A pillars.

To get to the speakers you have to pull the door panel.
Pull the door panel. There are only three screws. Two 7mm screws... one behind the manual lock and one slightly hidden behind the door pull and one T25 Torx with a shoulder washer under the trim cap at the rear edge of the panel about level with the pull handle.
Lift out the manual lock from the rearward edge as the front edge is a hook.
There's one pine tree push in trim rivet. The switches on my 2005 were screwed to the door card so you have to unplug them after you release the door card.
The tweeters are in the door card so you get to unplug them and the puddle lamp bulb needs to be unplugged.
When you re-install the door card start with the hooks on the bottom and then tilt it up and press down.
This video shows all of the removal points but isn't real clear on how to actually pull the panel. Just lift straight up on the door pull and then carefully tilt it slightly away to get access to the electrical plugs.
The Class 2 data connector to the switches was a beast to remove on mine so I just carefully worked with it connected. If you need to remove the data line the latch swings down and pushes the plug out of the switch module similar to some PCM & BCM plugs. Pulling the other connections from the switches provided me enough slack to R & R the speakers.
One of the old tweeters was squeaking and I found the other unplugged. I replaced them with the GM 14204326 UQ3 tweeters.

To access the UQ3 tweeters you need to remove the speaker screens from the door card or be a contortionist and reach through the large hole and jockey the tweeters in and out. I pulled the screens.
Carefully bend all of the tabs up and carefully push them through the door panel. One is slightly hidden at the top under the tweeter wire.
This is a good time to clean the cruddy dusty door card behind the screen and clean the screen itself. I used Dr Bronners peppermint liquid castile soap and a very mild brush with hot water on the screen and Windex on the panel and it didn't damage the finish on either.
You need an 11mm hex driver to remove the sheet metal nuts on the tweeters. Be sure to keep the 11mm sheet metal nuts. You'll need these to install your new tweeters.
When you have the tweeter installed carefully re-install the screen. It's a little fussy to get all those tabs in the slots... it helps to make sure they are all straight up... don't use pliers on them they bend easily with finger pressure. Once the screen is back in place bend the tabs back over while firmly pushing on the front without deforming the screen. I pushed directly on the outside over each tab as I was bending it and I bent most of them out from the speaker cavity... the top tab doesn't lend itself to bending out so bend it in.


I discovered an interesting thing when I pulled out the speakers... UQ3 speakers are part number 19116641. The speakers in my front doors are the $20 base model 15183361 units. My SPID claims she came from GM with UQ3 speakers. My guess is that someone replaced them with the cheapest speakers available from GM sometime in the last 15 years.

The UQ7 GM Bose 15236987 woofers or whatever you want to call em are a drop in replacement for the existing speakers. No monkeying with the plugs or the mounts. They cost right around $50 each.

The 15183361, UQ3 19116641, and UQ7 15236987 have the same factory connector and door mount.

Just replacing the four front speakers made a huge difference in the sound quality. I can actually turn up the sound without nails on a chalkboard from the blown tweeter and rattling from the speaker cones in the woofers.

This is a picture showing the difference in construction between the BOSE speaker and the UQ3 GM speaker.
Note the foam in the Bose speaker latching clip. It acts as a rudimentary spring to keep the latch and tabs from rattling. If you're replacing the old speakers just pull the foam out of the old speaker and the clip becomes very easy to compress.
http://johnnynightstick.s3.amazonaws...20speakers.jpg