SierraHD17

The G80 RPO code for locking differential has meant the Eaton Gov lock since it's introduction in 1973 in a pickup truck... not the mid 80's. G80 also is the same code used for a limited slip in a passenger car application until today. If you had a limited slip after 1973 in a truck it's RPO code G86. I would have to go look in my RPO code guide to see what the Detroit Locker's RPO code was because it was an option in the 10.5" 14 bolt through the 90's. GM recycles RPO codes constantly and uses them in multiple applications. It's just a code... If you had a 1969 Chevy truck with positraction as per the sticker in the glove box ( it's a clutch pack limited slip back then) it's RPO was still G80. The 9.5" and 9.76" 12 bolt is a redesign of the 9.5" 14 bolt which debuted in 1979. Yes you could install a Gov lock from a 1979 model year truck in your 2019.

I run Detroit lockers in every truck I own minus my 2013 because i haven't installed it yet. Even my 2017 has one. Does what I want it to do every time and is predictable as hell doing it. The Trutrac is pretty mickey mouse... and honestly lots of people get 200000 + miles from Auburns too... or oem G80s... or anything really. I use a Trutrac in one of my trucks front diffs as it better than being open... and they work well at that. Even the OEM's only use the Trutrac in front axles as that is where it does well on a truck... Not my cup of tea but its better than an open diff until it ultimately becomes one all on it's own. The old Gov lock has been around since 1973 in GM trucks and likely will still be used until they replace the axles with electric wheel motors. People mostly like it and it is what it is. If you dislike it you can replace it with whatever suits your fancy and enjoy it.

That video is neat and all but that's not actually how a Trutrac people talk about operates. There is no spur gears on the ends of the worm wheels to lock the gears together in a Trutrac and they actually run parallel with the drive gear on the axle shaft. Instead if you spin one faster than the other the principal is the worm wheel will be forced into the wall of the case and bind as the two will separate under wheel speed difference. The worm wheels spin with about half the gear overlapping the one on the opposite axle. That's all fine and dandy but it's pretty mickey mouse in the long run as it heavily depends on friction to the case of the differential. In that sense its much like how an Auburn limited slip relies on the side gears having teeth on the back side that dig into the case. Here is the Eaton exploded view video.

Someday GM will get out of the 70s... someday lol. These trucks all have the brake lock limited slip programming in them. The GMT900s had it too.

He can't even get an actual locker or limited slip of any kind for the 8.25" front as far as I know. There is nothing available as they are so weak they can't handle it. The 9.25" has a couple options but that's it.

Your passenger wheel hub is freewheeling with zero resistance other than the bearing. The drivers side is turning the gears and the driveshaft putting drag on it. Yes it will pull to the drivers side. When it's open all you spin is the spider gears and that disconnected passenger side axle....and not the entire gear set, front driveshaft along with the transfer case input shaft. How noticeable will it be on your truck? Do it and let us know lol.

It won't. Passenger axle has a collar that connects the inner and outer portion. In 2wd it disconnects so the passenger side freewheels. It will however pull to the drivers side. In 4wd it will hop and skid.

It's going to pull to the drivers side. With it locked and the passenger axle disconnected as it does you still will have load spinning the front driveshaft constantly on the drivers side that normally would just go the path of least resistance to the disconnected passenger axle. Since the carrier is locked to the drivers axle side it and the driveshaft will always spin where it normally wouldn't. Guys have been trying this since 1988 and it's not pleasant.

The piece that melted the cover and shot across the cab with the cover. Yes I glued the cover back on and pulled the 30 amp defrost fuse.

The melted cover.

Just like that... stabilitrack is gone forever.

Some of us drive on roads buried in snow and this stabilicrap makes the truck useless. I did this exact thing to my 2013 6.2 truck a long time ago and it's great... Except I just unplugged the sensor and left it that way forever. I have no use for any of the traction nannies in my trucks.. I still daily my 05 and heaven forbid it didn't come such equipped from the factory lol. I am going to dig around under my 17s dash and see what happens... I will be just permanently disabling it on that one too. And for the record even on the 07 to 13s it doesn't stay off pressing and holding the button. Sure you get the icon but my 13 used to still cut in at inopportune moments even with it supposedly disabled. Unplugging the angle sensor fixed that permanently. This nanny stuff just makes for a world full of even scarier drivers than they already are.

I can grab one tonight haha. I glued the melted back cover back on to hide the exposed contacts as this happened before the recall existed. I will probably pop it back off again.

Have you had the work done? Mine melted the plastic cover on the fingers that contact the outside window frame to give power to the center glass defrost circuit. I tried soldering it back on and I don't know what solder they used but nothing I tried would stick. It actually blew one set of the fingers off and took the plastic cover with it when it failed lol. The fingers are all blued so they were not making good contact. Truthfully I like to drive with the rear glass just cracked open so that probably contributed to it although I never turn the defroster on... truck does that on it's own and I can't disable it for remote starts. You can see the cover I mean in the bottom right hand corner of the middle glass. I'm curious what their repairs look like lol. I'm fine with mine never working again as I do not use my rear window to look out of but if it's not a total butcher job I may go get the recall completed.

Gm released the afm system that everyone likes basing this oil problem on in 2005.... all the way through 2013 the spec was 5w30 in the LS's... Little known fact is the bottom end of these LT's is identical enough to an LS you can interchange the cranks and rods... I know this... I do this stuff lol. Bearing clearances haven't changed either. Same goes for the lifters and how the VLOM distributes oil.. The pump has changed to a vein style with an electronic pressure relief but still. Now the only wrench in the system is differing specs based on application or engines for that matter. Of course a car is tuned differently.. and as pointed out the LT1 cars spec even quote on quote "heavier oil" at 0W40 and 5W40 for competition use and then 5w30 for daily use... If the engines actually differed mechanically then you could be 100% on oil being a problem but they don't... People forget the 4.3 which is still an afm engine and same spec as the 5.3 and 6.2 calls for 5w30 as well. So what gives?.. CAFE as pointed out many times. Ford boards have had this discussion for ages too after the 5 liter debuted spec'ing 5w20 in the trucks but 5w30 or higher under competition use in the Mustang. The bearing clearances and most parts short of the cams and exterior bolt ons are identical yet guys swear if you run 5w30 in a 5 liter truck it will blow up lol. It gets old after a while.

So by your logic why run 5w30 in a Corvette or Camaro at all? Unless being used in an abusive situation there is no need for it in daily driving. Now don't answer that because yes I know how oil breaks down so no I wouldn't ever use that water pretending to be oil in a car but that ignores the original question. Again... more semantics and now just some useless personal attack. You can't explain why 5w30 would cause an issue in a truck because you don't know... And if you honestly are friends with development engineers how about this... bring an explanation to the table on why 5w30 will damage the truck engines but magically will not under normal driving in a Camaro or Corvette.. A real one beyond "have you ever even looked at the tune" because yes actually I have. Everyone here will be waiting lol.

Still makes zero difference... the truck engines would be under more stress in a towing situation than a Corvette on track day. That's not even an answer or an argument but just more semantics.... 5w30 works just fine and GM did it for fuel economy specs in the trucks... this has been beaten to death over and over and over.. That's it... no black magic and no BS.

People to this day can't seem to figure out something simple. The L86 6.2 and LT1 Corvete and Camro share long blocks. The trucks spec 0W20 and the cars spec 5w30 in both wey and dry sump variants. When I say the same long block I mean part number for part number. The 4.3 specs 5w30... same afm system. In fact it's the same afm junk as the previous LS engines that all used 5w30. 0w20 was implemented for fuel economy... that's all. Do not even worry about it. Buddy just traded his 14 off at 85000 miles and it ran its whole life with cheap 5w30 because the engine was quieter... It will life a long happy life with clean oil in it.

Yup. Let it Rev a little bit. It's something people never understand when i talk about my 2017 and the gear swap. I only run a 295/60/20 which is close to these 2020 trucks stock tires With 4.56 I am about 2150 rpm at 70 mph and it does fine. Before I did the gears I was turning under 1800 rpm with 3.73's and the truck did not like it. I know people will run out in droves and tell me a 6 liter doesn't matter but it does.. the 6.6 has more power but it's not magic. Until I swapped gears for highway driving I ran my truck in fifth and never used 6th gear.. the mileage actually improved marginally and the truck just drove better. Of course now 6th is fine but I have the rear axle ratio to compliment it.

I still get better than 12.9 with 4.56 gears and 295/60R20s... that 12 mpg stuff is what my old 4L80e Lq4 trucks get lol.

Wow... amazing comeback. Have a good one.

It's not the same crank lol.. the stroke is 3.86" instead of 3.622". These things are all published anywhere. And it's the L8T... not L9T that doesn't exist so maybe that will help you look them up lol. You just said long rod is no good for performance under boost but now the 4.8 is... lol. So much for the bending long rods theory then. You really should look into the performance world... Nobody destrokes anything unless they just want to be different for the sake of being different. The LQ4/LQ9/LY6/L96 all do fantastic under boost... I can say that because I actually have two boosted 6 liters myself. But this isn't about 1000 wheel or boost...it's a real simple post about increasing performance. This 6.6 will make more torque and more horsepower all over the rpm band versus a 6.2... and it's going to be cheaper to buy. There is literally zero reason to buy a 6.2 for a swap with a larger cheaper alternative not riddled with AFM available. It's a no brainer. The mystique associated with the apparent "prestige" of "aluminum blocks" continues lol. I can't believe someone is arguing about 100 lbs difference in a 6000 lb truck... that's literally hilarious. That said I am done. The info is there and out there for anyone interested.

No. The ecm is of the new variety ( no word if its the half tons E90... need to get one) but you don't use that anyway.. use the existing 5.3 harness and the E92 ecm the truck has and tune it no different than you would throwing in a 6.2.

Pretty much. These stupid direct injected engines don't have quick reference numbers like the LS heads had which sucks... and to be a a different part number in the catalog all that is required is a different material used in an exhaust seat even though the head otherwise specs identical. I want to build a 6.6 LS from this crank but if it means custom pistons which it appears to be then I have to price that and see. My 2013's 56000 mile L9H sounds like trash and I have another L9H low mile core so I was hoping to turn that into a 6.6 and swap it lol. That said if I can get a 6.6 in the next bit i might consider buying a 17 or 18 half ton double cab with loaded cloth interior ( be sweet to find a max tow 5.3) and toss the 5.3 in the bin. Time will tell. The other idea is drop the 6.6 in my 2017 HD but who knows if that will work and I am totally on my own figuring that out. Fun and games!

Same bore in the blockat 4.065" just like the 6.2. I need to go find a 6.6 truck with the hood open but to be honest as cheap as GM is the same heads as the 6.2 is very likely. That or we will pull part numbers from the GM parts network and compare. They did the same with the 6 liter and 6.2 in the last trucks. Or hell... maybe the runners are larger. Seems like I am the only person looking into this and excited for it that posts anywhere. Seems like so many guys on other sites still have it in their head that new HD trucks use a 6 liter lol. I am getting one as soon as I can grab one.