swathdiver

See if water is getting inside the ABS control module. A guy on another forum discovered this, his acted up only on left turns when the water sloshed to that side of the board and shut down his brakes and worked fine while driving straight or turning the other way.

https://www.gmupfitter.com/files/media/photo/1291/20_Silverado_2500HD_3500HD_Electrical_Body_Builder_2019JUN21.pdf This might do it. On my generation, the "hotel" wire was coiled up unused under the brake booster and when one wanted to use, they attached it to the right post on the fuse block. I'd peruse the file but it is taking a while to load. If there's nothing in there, have a look around the website.

I believe Max Tow Package is the NHT RPO code and that means 3.73 gears. If so, then it's towing capacity, assuming 4x4, is 11,700 pounds with a GCWR (Truck and trailer) of 17,500 pounds.

In a way, yes. It positions the engine better in the powerband best suited for towing. NHT trucks also have an extra leaf spring on each side, you can buy a pair for about $60 to add one to each side if you feel the need. Towing 8500 pounds with the upgraded gears, you should be fine in the short term but over the long haul, I would want to either get a stronger carrier for your existing axle or replace it the larger one. Do those K2s have the engine oil cooler and external transmission coolers like the older trucks?

Ram Schmam. When a farmer see another buy a Dodge, he know he didn't have a good year.

My daughter just bought one; loves the 6.2 and NHTs 3.73 gears and it has a Zone 6.5 lift running 35x12.5x18s with Nitto mud tires for now. Curious, what kind of mileage are you getting and did you recalibrate the speedometer? She averaged 15 mpg on the highway on 91/93 and gets about 9 mpg burning straight E85 in mixed city/highway driving around town.

You do not have to replace the entire 12-bolt rear axle to upgrade to 3.73 gears. You can purchase a more stout carrier that is stronger than the one you have though and put the 3.73 gears on it. The front differential will handle 3.73s easily. Go to LKQs website and put in your vehicle and what you are looking for and they will show you what's available and for how much. Remember, your K2s have 12-bolt axles, both 9.5 and 9.76 depending on options. AAM (demandaam.com) was the original supplier to GM.

A set of Katzkins can tackle that obstacle.

The computer controls the output of the alternator and it seems to me that you need a new battery regardless of how it tests out. These computer systems don't take kindly to aftermarket parts so make sure to use GM OE or ACDelco Professional parts. Is your Silvy an NHT with 3.73 gears?

Plugged in my Sierra at GMPartsDirect and came up with these Tonneau cover part numbers for you to try: 22870545, 22870560, 20972501, 22870559, 22870558, 22870557, 22870554, 22870553, 22870550, 22870549, 22870546, 20972500, 20972499, 20972498, 20972495, 20972494, 20972493, 17802389, 19243693... Check these out first: 23128997, 19243600, 22878261 Key Word for spares appears to be "Service Component" "Tonneau Cover Component"

Hey Sparky, I do searches like this all the time. That part number is also color specific. You'll want to look for the other colors and see what turns up. When you find those, run searches including the words "instructions" or "manual" and some sites still include links to the pdfs for installation. You can also observe the shape of the Chevrolet cover and see if ARE or other brands match it as GM undoubtedly contracted with someone to offer it. Try ebay too using a variety of search terms to see what comes up. Welcome to the forum.

Go with the 3.73s. That's what the NHTs in the previous generation have and they are towing beasts.

Fix the cats and whatever killed them and then give the transmission a chance to run right. The 6L80 is an awesome transmission.

Weird. I'm in 5th at 35 mph with no jumping around and mine is much older.

It's not very common but more common in your generation truck. I would "flip the pill" which disables the thermostat in the transmission. Send in an oil sample to Blackstone Labs for analysis. I did, said my trans was fine but the fluid at 36k had 10K miles of life left in it. Oh, check Sonnax's website for all of the latest improvements they offer and why, especially on the converter. I bought the 6L80 shop manual off of Amazon and Art Landeck's 6L80E shop notes booklet too.