Rick_

There is a new software security system/encryption on the '24 and up GM diesels and as far as I know, not even the Canadians nor eastern bloc hackers have jailbroke these ECMs. Hence, you can look hard but there are no delete kits for a '24 GMC/Chev Duramax. '23 L5P, yes, '24, nope. My '24 has had no ATS issues in 60k miles, knock on wood.

I traced the atf cooling system in my 1500 and it comes out of the transmission, into the bar/plate liquid/liquid heat exchanger, as stated above. Then it crosses over to the external thermostat/bypass and then to the aux cooler in front of the main radiator. Hence, on this routing, the PPE thermostat bypass eliminator is an $85 piece of bling that does nothing for reducing atf temps on this truck. I think I'll temporarily clamp a needle nose vise grip on the coolant feed hose to the bar/plate cooler and see how much the atf temp drops. With the use of ULV trans fluid, I'm not convinced running the trans cooler than OEM spec is going to be detrimental to the life of the transmission. I found this interesting on the Dana/Long site stating that they make transmission cooling/heating bar plate heat exchangers. I worked with Dana/Long on a few projects when I was at the gas powered fun factory. https://www.dana.co.jp/downloads/PTG/Long/Dana_TOC_SpecSht.pdf Bar plate heat exchangers are just a stack of stamped parallel path fluid channels, assembled and vacuum furnace brazed to make the final assembly. Want more cooling/heating, just stack more plates until you run out of package space. Anyway, thanks for the info, much appreciated.

So you are saying that there is a water to oil transmission fluid "heater" along with an air to atf heat exchanger? Where do I get hold of a diagram/microfiche of that routing? Is the water to oil cooler a bar plate job between the trans thermostat and the air to oil cooler? In the 2022 10L80/90? valve body there is a valve called the Cooler Thermostat Valve that gets modded to eliminate regulation to the flow to the cooler. There are two styles - the 2022 has no brass thermostat, but later versions seem to have it. Testing today after the valve body kit install, zero change in gauge temp unloaded - 180F at 84*F unloaded, so the atf heater is doing its job. The positive so far is the lag in shifting from R to D has been eliminated. There is a brass "thermostat" in the Cooler Thermostat Valve that is removed with the NextGen kit for the 10L1000 - 135F gauge temp with a 5000lb boat in small rolling hills at 85*F.

Installed the PPE bypass on the RST last week. With ambient temps between 75-95, the trans temp dropped from 195-198 unloaded to between 180-185. Not what I was expecting (also has the Max Trailering package). I have a Nextgen diesel valve body upgrade kit going in this week and the remaining thermostat in the pressure regulator valve will be removed and I'll see what happens. I did the same mod in the Valve body upgrade kit for my '24 3500 HD Duramax and I haven't seen much difference in trans temp but I've just been running back and forth to town so far.

Correct, it is the 3.0L diesel (LM2). Thanks for the info.

Does anyone know if the GM 85628205 and 85628208 are interchangeable? The 85628205 is an assembly of the seals mated to a thin metal shim and the 85628208 appear to be just the rubber seals without being an assembly. The reason I am asking is that I'm installing a PPE Thermal Bypass Valve and it doesn't come with seals.

I am currently trying Archoil but I've noticed no magic with regens or mileage changes. I may bring some Power Service for the return trip when I go to AZ in February. Other than that, local stations carry blended fuel in the winter so no issues on gelling.

A company I worked for used to order these, upfit to rear duals and avoid having to stop at weigh stations just for having a two place sled trailer in tow with a couple passengers. Their 1 tons were for the 8 place featherlight gooseneck sneaking in at just under 26,000. MN has a license tab fee break for 1 tons so that might be a consideration. My 3/4 ton diesels rode and handled way better than my 1 ton. The Max trailering package on a 1/2 ton 3.0L is not quite enough spring to handle a tongue weight of 700some lbs and the 3.73 went away for 2023 and newer in favor of a numerically lower (3.42?) ratio. I like the 3.73s in my 2022 and air springs are easier to add than air bags in coil spring rears...

Here's some info from nextgendiesel on how to extend transmission life. Nextgen also sells valve body repair kits directly to GM dealers now to fix the issues the 10spd transmissions are currently having. https://nextgendiesel.com/blogs/transmissions-101/top-5-ways-to-extend-the-life-of-a-factory-transmission For temps over 200F, the seals and o-rings need to be made out of a more expensive HNBR rather than cheap nitrile. Also, planetaries and shaft/bushing interfaces like a bit more lubricity than what LV and ULV fluids afford. Taking the word of a dealer is not a be-all end-all answer as I've had dealers and sales managers lie to me face to face. My experience with automatic transmissions and heavy duty hydraulics is that a temperature limit below 105C makes for happy customers. YMMV

My wife's '22 RST 3.0 with our 5000lb boat running 70mph in rolling hills at around 3000ft in low 90's temp runs up to 201* even with the Max Trailering package. Looks like it's going to get the PPE bypass. My '24 3500 Duramax barely cracks 150* with the same boat running between 70-75mph.

...except if one has the Max Trailering package. It would be cool if there was a workaround. Excerpt from the description- SKU: 84993582 Positions:Rear Other Names: Suspension Lift Kit Description: Each system features front and rear passive monotube dampers specifically tuned to the chassis, jounce bumpers, rear leaf spring spacers and much more for fully integrated installation. An exclusive Front Camera Reconfiguration and an Electronic Power Steering Calibration is included, so that all driver-assist systems continue to function seamlessly. Read the vehicle’s Owner’s Manual for important driver-assist system feature limitations and information. Expert installation by an authorized GM Dealer is recommended. The 2-inch Suspension Lift cannot be installed on all regular cab trucks, 2019+ Chevrolet Silverado 1500 Custom Trail Boss and LT Trail Boss, all Max Trailering Package trucks (NHT), all Snow Plow Prep-equipped trucks (VYU), or any 2019+ Chevrolet Silverado 1500 equipped with composite rear leaf springs (Chevrolet LT Trim with 5. Kick the ride of your vehicle up a notch with the Chevrolet Performance Trail Boss Spec Lift Suspension Upgrade System. This Chevrolet accessory can help to personalize, customize, or optimize the capability of your vehicle for your lifestyle and use. Kick the ride of your vehicle up a notch with the GMC Performance AT4 Spec Lift Suspension Upgrade System. The only 2-inch Suspension Lift designed, engineered, tested and backed by Chevrolet specifically for the All-New Silverado 1500. Developed by the same vehicle-level engineers that built the truck, this system was tested under the same grueling conditions, and will not void the New Vehicle Limited Warranty.

The RAM Ecodiesel DEF tank capacity is 8 gallons. I could go almost a year without filling it on my '17 ECO; GDE tune and 3-4000 miles towing a 5500lb boat, doing about 12-15k miles/year. My '22 1500 LM2 gets maybe 3600-4800 miles between DEF fills. The tank capacity is 5.3 gallons which explains part of the fill frequency difference between the LM2 and the Ecodiesel.

I have a 2022 1500 RST 3.0L w/Max trailering package and I want to raise it to have the same ride height as a similarly equipped 2022 1500 LTZ with the max trailering package. I had a '22 LTZ w/Max Trailering and factory 20" wheels and it barely settled with my boat on the hitch. I did have helper air springs but never put over 5spi in them. What is needed to raise the front? Just springs or spring spacers? To raise the rear, is it near the same as the afore-mentioned spring blocks, jounce bumper plates, and associated hardware? TIA

Are you the same guy from Wisconsin posting this issue on X also? If you're from the Milwaukee area, they use some of the most aggressive "salt" in the winter I've ever experienced. My '22 Silverado I bought used from a WI dealer had a crystalline buildup on the cab underside - I've never seen that before. Since I wash my trucks weekly, I haven't experienced any excessive undercarriage rust...

My fiver started the hucka bucka on the way home from Camping World. Called up my buddy and he said he always pulls his fiver with a full water tank. I filled up the water tank, added a second battery, put in all the equipment in the storage compartment and the bucking is nearly eliminated. 19th Ave in West Fargo could get my trailer bucking anytime no matter how it was loaded so some roads at lower speeds may induce the issue but for the most part I'm happy.