davester

Can you thin out/remove material in the console between the charging pad and the phone? Ideally, the phone should rest on the pad, everything between it and the phone reduces how well it works.

It's possible the post on the door itself is damaged/broken. Maybe try using your phone to take a picture of the area, or an inspection camera, and see how it looks.

Um, what delrin shims in the NP261/3XHD transfer case are you talking about?

the free online vin decoders typically just have generic info. you need the actual vin, then go to a dealer or there is a gm email address (don't know it offhand) that you can send the vin to, and they may email back the build sheet for the vehicle.

try local junkyards, and/or online used-part sites.

get a code reader that can read codes. You probably should get a more advanced one that can also get codes from the transmission as well...

It's all data on '05, the light isn't based on the physical location of the indicator, and the gauge isn't analog. If the light is on, and the voltage reads zero, that really points to whatever computer that does the actual reading (the ecm I believe) says it's zero/low, for whatever reason... But it's either buy/borrow the tools to figure out what's wrong, or throw parts at the truck...

An intermittent connection or broken wire somewhere? Depending on where the problem is, the problem may generate a code (you may need a more advanced code reader to read it).

You want 04-07 (classic '07, as there was a mid-year redesign that year) for the easiest time. Earlier stuff used a different way to secure the door panel to the door (and the arm rest to both).

maybe check for codes from the tcm? This takes a more advanced code reader than the regular cheap ODBII code readers. But also maybe unplug/replug the electric connectors, and check that the shift cable is properly attached.

I would suggest using a mechanics stethoscope to narrow down where exactly the sound is coming from.

Like I wrote, your best bet is to get them from a junkyard... They are slightly tapered, and GM never offered them as a separate part.

Well, I don't know if/how unusual that is, for a 261 to be in a 2500HD. I just know the '06 2500HD I bought had a 261HD, as well as the junkyard 2500HD (don't recall the year) had a 261HD as well (I also botched a seal, ran it dry, and swapped it out).

Yeah, that's weird. I have an '06 2500HD/6.0/4l80e (used as a parts/donor truck to upgrade my '04 Sierra 3500 to 4wd), and that came with a 261HD. Perhaps check the chain measurements, and perhaps input/output shaft spline counts, I believe they are different between the 261/261HD, as perhaps someone just swapped the case half without changing the tag? Or perhaps it's really a 2500LD? Google "np261 vs np261hd differences" and make sure of what you've got, as there are some different parts between them.

First, make sure you buy/get the RIGHT parts/kit. There are at least 3 (possibly 4) versions of the NP261 (NP261, NP261HD, NP261XHD, and possibly a NP261SXHD). Most likely your truck has the NP261HD, but there should be a round tag on the rear half that you can clean off to see. There's a good youtube video of a mechanic assembling one: The input shaft and front output shaft use 2-piece seals, that are certainly easier to install properly with the right seal driver. And it helps to have a good, small puller for the small pin bearings in the housing/shaft. I would suggest just getting a used TC from a junkyard and put in new bearings/seals/pump rub kit, probably will be cheaper than buying a new rear half.