2018GMC

AFM on all those miles? 5.3L and 6L80? Good to hear it’s been reliable. Cheers [emoji482]

I picked up a set of AT4 wheels and tires. I like the look of them but this set came with the smallish 265/65/18 Goodyear Fortitude HT tires. They’ll be fine for all the summer driving and can save some wear on my 285/70/17 BFG K02. Noticed an immediate weight difference. Fortitude weighs 56 lbs mounted on 18” wheel. BFG k02 Load Range E weighs 81 lbs on 17” wheel.

What issues were you experiencing? Did your 8 speed have the original fluid in it? I think all the 8 speed prior to new body style t1xx came with the Mobil hydroscopic trans fluid which can accumulate moisture over time and cause shifting issues. My 2018 has original fluid, only 10k miles but no issues other than occasional light clunk if you let off gas in traffic and it upshifts. Did you mean transmission valve body was replaced?

6.2 if you are already interested in a higher trim truck. If you are looking at lower trim then go with the 5.3. Previously GM made you buy SLT or LTZ trim to have 6.2 as an option. I believe for 2020 they are offering it in LT and SLE?

Looks good. I like that color and am partial to crew cab standard beds!

In Canada ?? yes. I’m in the USA ??. I haven’t received anything in the mail. I checked my vin with GM.. https://my.gm.com/recalls Currently, there are no recalls or programs associated with your 2018 GMC Sierra LD Crew Results last updated: Feb 16, 2020

I pulled the fuse for the rear window defroster long ago. Rear window slide still works. Need to check if my tow mirrors are still defrosting.... It would be great if GM offered $$$ back for a feature we paid for but is defective and potentially dangerous. But that ain't happening.

Thanks! Saved for many years to put a big chunk down. Made larger than minimum payments and it’s finally paid off!

Haha. Yes!

Anyone running the DT version of K02? You have the DT version if your sidewall does not have the 3 peak symbol. Different Tread (harder) compound for longer wear and comes with mileage warranty. But you loose the snow rating 3 peak symbol. https://www.wanderthewest.com/forum/topic/17212-new-bfg-all-terrain-ta-ko2-dt-tires/

I see you have 2500HD in your signature. If you have the gas, you could go either 3 peak or DT. If you have the Duramax, get the DT due to the additional wight and more importantly, tire wearing torque!

I say 3 peak for a half ton. I would only go DT on 3/4 ton or a truck that gets a-lot of miles. I have BFG K02 3 peak on my 2018. They prob have 20 - 25k on them. I ran them on my 1997 k1500 for 15k miles and did some towing. They are showing wear but are 5 years old this year. Still probably 40% tread left? noticeably less tread in center of tire, I keep pressures at 48 psi cold, could probably reduce that down to 40 - 42.

Paid off!!! ? ??? ??

Hope you are still fighting and winning in 2020! We miss you on the forum!

Great writeup and pics! When do you recommend first, second, etc service for the daily driven truck / suv with occasional weekend towing?

Does the pump grinding into the case happen with the 8L90 when it has the factory Mobil 1 fluid that is hydroscopic? My 8l90 shifts fine but I only have 10k miles on truck. My truck was built 12/2017 which means it has the older Mobil 1 fluid that is hydroscopic? I haven't received any notice to have the fluid exchanged to the newer type. That is a TSB, and you have to prove your trans is shuddering correct?

Magnaflow 22" 12909 or 14909. Have exhaust shop cut out stock muffler and flapper. Weld in magnaflow. I kept resonator after muffler because it is straight through and I still use V4. Done. Only downside to magnaflow is its pretty quiet. I can now hear cold starts in the house and it sounds like a V8 should sound above half throttle or 3K+ rpm. But still quiet at highway cruse and light throttle.

At least you have a dipstick! The 8L90 and 10L90 don't have dipsticks! Just a "check" plug you pull and see if fluid comes out when at temp.

I have bilstein 5100 on 3rd notch for 1.75" lift. Nearly 33" (32.8") BFG K02 Tires. I can still pull down 20 - 22 if I drive 65 -68. If i went your speed i'd prob get the same mpg as you. On a 50 mile 2 lane road with cruise set at 58, I averaged 28 mpg. As others have said speed kills mpg when you're driving a brick with the frontal area of a sheet of plywood.

I have 33" tires and multiply truck miles by 1.03% (3%) to get nearly accurate GPS mileage. https://tiresize.com/calculator/

That sucks. Hopefully dealer gets it sorted. If not you have a bunch of equity in a 19 and can trade for a 20, 21, 22, etc.

OP - that really sucks about your engine. Good news is you will have a better than new replacement in a truck that’s probably paid off.

Was there a bad batch of springs? I’ve seen info on this forum about keepers coming out and some bad head castings. Guess we know why 2016+ models only have 60k powertrain warranty. my 2018 just turned 10k miles. I’ll probably hit the 5 year mark before 60k miles.

Now for the exploding window recall / fix in the USA. I pulled the fuse in mine since i rarely ever need it and its always automatically on in low temps.