swathdiver

Nothing that money can't fix. Look up Castech heads, Pump Rub for the transfer case.

That's ridiculous, Have seen those prices for both ends, not each end! Would be more inclined to run 3.73s or 4.10s with taller than stock tires. If you need more gear, drop to a lower gear in the transmission.

https://www.tirerack.com/tires/tires.jsp?tireMake=BFGoodrich&tireModel=All-Terrain+T%2FA+KO2&partnum=405R7KO2RWL&vehicleSearch=false&fromCompare1=yes 34 x 10.5 x 17 - Nice to have over 8 inches of sidewall. They fit fine on GMT900s and K2s, not sure about T1s but I think you have more room in there then we do.

While rare for a 5.3, they sometimes break a valve spring, pull the valve cover on that side and have a look.

Get a wrench on your torque converter bolts. L33 is a great motor.

That's one of the funny things with E85. I've towed 4-5K pounds running at about 72% alcohol content and she wouldn't go into 5th gear between 60 and 70 mph. Back on gas or under 20% ethanol and she pulls fine and the gas mileage of course about doubles. Mine was also tuned by BlackBear.

I replaced mine with a new(er) one, came across this video that you might find helpful.

Yep, hit up Ebay for new OE sensors that won't cost an arm and a leg.

Remote start will not work if there are active codes and a basic code reader cannot see all codes. The bi-directional scan tool, like that Snap-On machine ought to be able to see the commanded and actual fuel pressure and the Long Term Fuel Pump Trim. If you plan on keeping this truck you really need the aforementioned subscription to AllDataDIY for the shop manual and your own Tech-2. It's the most important tool in your toolbox for working on one of these and it will quickly pay for itself. They are not very expensive right now either. Does your truck have RPO code (glove box for the sheet) AP3 or AP8?

I don't know what's wrong but know how to find out. A subscription to AllDataDIY will provide you with an online shop manual for your truck along with the trouble shooting guide for the seats. Access to a bi-directional scan tool like the Tech-2, that can read BCM codes, will tell you what the problem is in moments, there will be stored codes and the symptoms telling you why or how something has failed.

Yes, in the archives of the old Avalanche forums, the guys back then used HP Tuners to tweak the vacuum settings so AFM would stay on longer. There were some other things that they did that are lost to me now, interesting stuff. They were getting 25 MPG.

https://www.gmupfitter.com/files/media/photo/836/18_Sierra_Body_Builder_2017AUG31.pdf Seems to me that it is already wired up, I searched "Trailer auxiliary".

Gears might be broken or the motors burned out. Since that has happened, there should be codes telling you exactly what failed in the BCM module.

No, the updates are written to memory, they are not temporary. What's going on?

Factory hubs are good for about 100K miles, Use GM OE or Timken as replacements. Could also be a ball joint or even your tires.

Might be the brake switch on the pedal or more than likely it is the module on the steering wheel. A Tech-2 or equivalent can test and discover the problem pretty quickly.

Well, it could be a coincidence and the blower motor resister died and needs replacing.

Get a Tech-2, your truck was designed to be worked on by it, it will pay for itself in the first repair or near so.

You can press a button between the cigar lighters to turn park assist on or off. Try that and see what happens.

Did you put the old radio back in to eliminate the chance that the new one caused the problem?

As clean as you keep your fluid Marty, I doubt it. Mine is almost there too. Never seen anything about it or how it works save for that explanation given to me once. Just stumbled across it while exploring the Tech-2.

The first sign of trouble usually occurs around 160K miles when the solenoids need to be rebuild in the TECHM and this can be done on your kitchen table. Change the fluid before 50K and it will last a long long time. Not sure about the T1s, the K2s introduced a thermostat to keep the fluid temp at 195 like the coolant, bad for long life, get rid of it if you can. On my 900, there is a place in the computer to enter the kind of tires you are running. A technician on here said it was to adjust how the brakes operate if I remember correctly. Using a Tech-2, it knows it has Load Range C tires and at what air pressure and the truck stops on a dime, about 130 feet or so from 70.

Timken.

You may have inadvertently had your truck tell you about a previous tamper condition too. See page 35, left side of that book.

Well, it wasn't the transmission that failed then, it was the converter! 6L80s are very reliable but were made less reliable when GM put the thermostat on them to help with emissions. Get rid of it and change the fluid every 40K miles or less if towing a lot and they'll last a long time. Average life in a GMT900 is about 170K miles and that is usually just the solenoids that need rebuilding which costs $100 plus fluids and you do it on your kitchen table.