davester

...probably won't get a response, Platinum LBZ hasn't logged into the site in more than 2 years...

In particular, the speed sensor at the rear of the transfer case would be the first thing to check...

It's on '07.5 or newer...

Pretty sure no GMT800's had cylinder deactivation. That didn't start until some of the GMT900's...

Don't work on the truck right before the trip unless you absolutely HAVE to. Nothing like stressing out over having something go wrong while fixing it, or it's the wrong part, or whatever right before the trip, and then rushing to get it done so you can go on the trip (which makes it more likely something goes wrong with doing the work). Do some reading up on how the specific trailer brake controller you have works, how to set it, and then spend some time configuring/testing how it works with the trailer, after it's loaded, before you get out on the road in heavy traffic. You want to make sure it's working right before you get into traffic and/or on the highway.

You might look harder on gmupfitter, it has offsets for where the frame crossmembers are, how tall it is at various points, where the body mounts are. Only thing it doesn't appear to have is thickness of frame metal, which is trivial to measure...

Oh yeah, all kinds of stuff can be wrong and the CEL will be off, it's only used to notify you of emissions related problems, not problems in general. I would suggest getting a tech ii from ebay/amazon, not that much more than a more advanced code reader (one that can get stuff from the tcm, abs, srs systems), but it can read codes from all the computers in your truck (there's more than 10, varies with what options you have). You can pay to diagnose the problem, or pay to randomly throw parts at it hoping to fix it...

When you filled it, did you follow the procedure outlined in the owners manual for checking the fluid level? It's more than a 1 minute task... Don't know why they would weld your drain plug in place, when I rebuilt my 4l80e, I added a drain plug to the pan. It makes the drain a bit easier/less messy compared to lowering the pan and having it pour from a corner. And your description of your fluid change doesn't really make sense. The "normal" thing to do is a pan drop/filter replace, and that replaces only about 1/3 or so of the fluid. A flush replaces all the fluid. Maybe describe what you actually did to change the fluid?

It could be legit. I put on about 130k over the last 7 years or so on my truck, and I believe the hr meter is in the low 3000's now (it had reset shortly before I bought it, was sitting around 325hrs then). It's a daily work truck, not a lot of idling, around the city...

Don't expect to be able to add that feature. GM has really cut down on enabling people to add options to vehicles after it's been built (for example, the built-in trailer brake controller, you can buy the parts, but can't get GM to update the programming so it works).

I know for my 3500/6.0, it really sucks to change the output hose from the pump, which is what you have to do to swap that line...probably sucks even more with the larger 8.1

...not sure if the high-pressure line that goes from the pump to the hydroboost will be able to screw into the steering gear (which is what you would have to do to bypass the hydroboost)...

It sounds like it probably is their fault, but it sounds like they aren't going to pay for anything, or perhaps might give you a small discount if you get them to replace the transmission. But, based on what you said of their work, there is no way I ever bring any vehicle to them to diagnose or repair.

do you mean fender liners? From googling, it appears rough country makes some for '14-'19...

Be careful with removing the plastic caps that go over the clips. They are for retaining those clips, but the caps aren't sold separately, and they are easy to break. When I did my lines, using a pick wasn't too bad.