Kerry Pulaski

She was level on jack stands. Let it drip out to a pan till it stopped. Merely a table spoon dripped out, then capped tight. As the spec. does say to -0- at fill hole, that is max fill level value. I even had the Qt's of 75w-90 in hot sink water for 15 min. to make it easy to flow. If cold and stiff, then could force an overfill before capping the fill plug. I work on industrial machines for over 43 years. These use precision planetary gearboxes. Oil viscosity and levels are critical. I expected the same care and precision with my GMC dealer........I hate teaching a supplier of high tech product.

My '24 2500HD resolve.......Rear diff took 1.5 Qt. to get a drip out the fill hole. (measured 1.25" low with Q-tip nylon stick bent 90 deg.). Front took .75 Qt. (measured 1.00" low with McGuiver Q-tip). Dealer did give me 2 Qt. at N/C of 75w-90. I had no more time to waste on this. Have jack, jack stands and creeper..done. I asked the service manager to check this before new delivery. Gave him a printed copy of the blogs as well, with the pre-delivery page checklist, before I took delivery. Said they did, but said the tech used a spec for a 1500 ???? Yea , good help is hard to find but.....an 11.5" or 12" axle..really ? I service , install and sell heavy industrial machinery for 43 years. Have a hard time with mistakes on my planned purchases, to babysit. Thanks to All, for these posts, to alert us to pending disasters. Safety in numbers. Happy Holidays !

(@gemarsh)(@64BAwagon)(@AerosmithPML), Thanks all for the replies. Starting to piece these events together, sounds like the programming on cold start gas or diesel, loads up the trans., for a friction and fluid circulation warm up ? And no darn trans dipstick to also look at. Will look tomorrow if the ScanGauge III, X-Gauge list has any readings for Trans Fluid Pressure, as it does for temp. That would be great to monitor cold and warm situations, and warm up events.

This is a shocker. At 2500 miles new, around 20 to 25 degree ambient, cold start-up, Duramax goes into high idle right away. Still in Park, after a minute or so, I heard a Bang, looked over and saw the truck rock slightly. On level driveway, electric park brake was not set. Hearing that Bang and seeing any motion, scared the xxxx out of me. So far this happened three times, when it sat cold below freezing for a day or two. I added the ScanGauge III, after the first "In Park Lurch", and found no Error codes to document. Now at 4,500mi. on O.D., back to 3,500mi., it's been above freezing, and has not happened again. I did not check yet, but does anyone know, if the H.D. column shift is a mechanical link to the Allison, or "By Wire" controlled ? Using the park brake ever since, even on the level just in case. Next very cold start, will have cell video going to try & document.

Owner of Suspension Maxx, advised against ANY gas filled shock, in a GM single steer application, due to Bias Pressure in one direction. In this case, will always force the steering track to the right, constantly. Ram & Ford that have dual steering shocks, using opposing pressure gas shocks is OK, to balance the force. Installed mine, and found it not only stops steering wheel shimmy on my gravel driveway, on bridge expansion joints, manhole covers etc., no wheel jerk. Also adds a nice stiffness to the road feel, in the steering wheel.

2500HD......See the additional loading you will carry, the 1500 will be a "White Knuckle Ride" every Ground Hog Movie Day. I was so unhappy with the 1500 as a temp. truck to haul my tools, bed slider, and cap, waiting on my replacement 2500HD. The 1500 handled poorly, only adding rear air shocks got me by as a cheap fix. Cap I would consider, is one without side windows, but fold upward doors, to access tool shelves on both sides. Leer, A.R.E. and other Mfg. have these "commercial Contractor Caps". I saw a fiberglass one yesterday, contractor style, with larger opening side doors, at my hardware store. Should have took a pic. Looked impressive, as it was taller than the pickup roof. Bed slider was a great help with by bad knees, for my contracting needs. New to me..... more slider tool storage. Cap-Pack inside cap slider roof storage. Just saw this on ishler's.com . My quick thought is this may be able to hang off of the existing roof rack support mounts on my cap. Happy Holidays All !

My Front Diff. is 1" Low as well. Transfer case is OK. GMC mfg. in Flint. The Q tips I got for the shop are a Nylon stick not wood. Think they were designed for ear wax removal, thus the odd smaller end of the tip.

Had a '18 1500 as a temp after my '16 2500HD was totaled in a multi vehicle pile up. Had to get the '18, was on the lot with my totaled '16 truck at my dealer, as my '16 A.R.E. fiberglass cap would fit, swapped over the Bed Slider as well. My Bed Slider is steel, so heavy. They do make aluminum ones. The '16 drove like xxxx, with little tools in back. Sway, hit bump stops.....all the time. Temp solution was adding Air Shocks in the rear. Go for the 2500. My special order '24 came in this July.

Got to check my '24 H.D Rear axle fluid yesterday, at 4200 mi.. 1-1/4" below the fill. Used a "Q" tip bent at 90 deg. as a dip stick. XXXX'd I asked the dealer service manager, specifically to check this, before delivery with 23 mi. on the Od., and gave him a printed page of these blogs to boot. I topped it off with the AC-Delco 75w-90 as in warranty. Giving receipt to my GMC dealer as had to do this quick on my time and expense, getting oil at closest GM dealer before close on noon Sat. Thanks to all for the heads up, on these should be "Assumed" good to go new vehicle delivery checks.

Service manual #16637297, is this PDF downloadable ? as (@64BAwagon) posted an except from it.

(@64BAwagon) Mentioned the Front end Alignment pull.....Same experience. My new '16 2500HD, drove off the lot, going home pulled hard right, even on left side of crown of a secondary road. My 3rd. trip back to the dealer for #3rd. alignment fix, as still pulled right wicked bad, service manager said will put his 26 year veteran tech on this issue. As he drove a 1/2 mile, said he does not agree with the GM H.D. alignment specs, and if I would let him put his own special sauce spec's on her. 40 min latter, said I drive. Darn spot on perfect. Can now drive with thumb and index finger, not a death grip. Specs attached. Glad to say my '24 H.D. is good out of the box. Just adding a Suspension MAXX steering stab. shock kit, tho, as the H.D.'s still wobble the steering wheel a lot on gravel. On the highway it's great. GMC ALIGN #3_12-6-17__RIGHT CASTER INCR.pdf

GM dealer parts dept. printed out the attached GM lube document #5258436, for my '24 2500HD (and 3500). Says 75w-90. He double checked with his service manager, with my question of the "LS" version of 75w-90, being "LS" for Limited Slip Diff. additive. Said NO, not needed, just the Synthetic 75w-90. Makes sense as (@Grumpy Bear) stated the HD axles are "Lockers" not a Limited Slip clutch type. Also reason on one very tight 90 deg. corner of my shop stone driveway, it chops up the packed stone at 10 mph. My 2500HD a Unicorn of sort, as the option "Max Trailer Pkg.", gave a 12 in. rear axle, frame and spring overload pack from a 3500HD. GVW at 11,700. So I guess the HD Locker Axle is what is called the G-80. Thanks to (@Grumpy Bear) also for posting the 75w-90 viscosity test chart. Most informing on the brand results. Happy Holidays, All ! GM '24 H.D. LUBRICANT LIST #'s.pdf

OOopps, forgot this attachment from Scangauge Support. This is their confirmation of the X-Code for "GEAR". REPLY 12-6-23_FROM_SCAN-GAUGE-III_Re 2024 GMC 2500HD Duramax Kerry Pulaski - GM Contact Us_REPLY #3.pdf

SCANGAUGE -III VALUES FOR GEAR.pdf

These values do work , just put into my new SC-III, Shows all 10 trans gears shifting. Duramax starts out in #2, unless in manual or 4x4 lox range. Put these in a vacant X-gauge slot. SCANGAUGE -III VALUES FOR GEAR.pdf

SG-III PDF Manual attached. SG3_SCAN GAUGE USER MANUAL.PDF

Starting on page 31 in the SG-III manual, shows how to Add more displays to the X-Gauge list. 4 lines of code to type in, then assign a name for it, in an empty slot, someone did "GER" for his SG-II, can do "GEAR" for the SG-III. Going to do this in mine today. On the https://www.scangauge.com/support/x-gauge-commands/, says can see the codes to type in.

Just looked back into the posts by Gregg , to last Sat., and saw the X-Code #'s, he put in his SG-II that show "GER", is working, and 64BAwagon says works so far in his SG-III. Will put those in my SG-III today, and see what I get. Thanks All !!

64BAwagon, When you have time, could you share the X-Code #'s you put in the SG-III ? Long trip tomorrow see if it works. Happy holidays all !

Gregg; Can you share the X-Code number you added ? Better results than I am getting. Mine Only shows a "Suggested Gear" in the X group, and it stays at "Neutral, and never changes when in motion. Have a long trip tomorrow for work, would like to try and put that "Gear" code in, and see what happens. To monitor what gear you are in for towing would be most helpful. Thanks.

64BAwagon, Do you actually get an "In Gear" selected reading ? My Duramax 10 speed does not. Only shows "Suggested Gear", that stays frozen as Neutral. ScanGauge is sending me a data logger to map my '24 PID signals.

ScanGauge replied to me again today, and are send out a Data Logger to me to run for 30 min. to track all PID signals, as all they asked me to try on X Scan, did NOT pull up the code to record the actual Gear in use. Will let y'all know what I info get next. Suspect will take a week or so.

GM removed the frame cross-member welded mount for the steering stabilizer on the HD's in '16. Going up my long stone driveway in my new '16 2500 HD, the steering wheel was jerking back and forth badly. Looked under my friends 3500 HD, and saw the mount and a shock absorber to the cross link arm. I made a paper template off of his, and had my customer transfer that to a CAD drawing to cut one for me with his laser (for bolt hole accuracy), Mig welded it on. Added the shock, Worked great, shimmy and some road wander was gone. In hopes my '24 2500 HD steering geometry was improved.........Nope. Going up the long crush stone driveway, wheel shakes like heck. Found several mfg'g offer bolt on kits. Beware !! I deal with metal fab for 43 years. Zoomed in on these brackets on line, some look very good. But the bolt through mounting on some to the cross-member, was very questionable. With those, I saw that there was no provision (thru tube in the cross-member) to add for that bolt) to stop pulling in the cross-member, when torquing it down. At the lower control arm rear bolt where the other end of the bracket attaches to, only one mfg. had a key'd washer, to spread the load, when re-torquing that bolt back down. I called that mfg. to also ask why he does not offer a gas filled shocks like others do. He explained, these gas shocks exert substantial pressure in one direction to the right, on the cross arm. Makes highway driving a PITA. I asked if ANY gas shock mfg. offers a special "neutral bias gas" version IF that is design possible ? Said no, it's a std off the shelf gas shock, just the proper length to fit this application. Found several posts on other sites, with GM owners complaining of this right side terrible pull. This mfg. explained, he Does offer Gas shocks , like for Dodge, Ford and others, where Dual gas shocks can be mounted in opposing force directions, to keep the steering Neutral. Said in GM truck applications, the conventional high quality shock works just fine. I should explain what drew be to this mfg. to answer some questions. Reasons: 4. 1) Some vendors sell his bracket, but offer it with a gas shock or conventional. His site, only offers a conventional non-gas shock. 2) This product bracket includes a "Key'd" washer, to mount the bracket on the lower control arm bolt. This properly spreads the force on the cross-member 100%. Other suppliers that copied his basic design do not. Added cost ? Yes. Maybe a buck or two. To spread that load 100% around that bracket & bolt, is just a good engineering and safety practice, in a high load / stress area. Kudos. 3) To include a Through Cross-member Sleeve, to also spread the load evenly to both sides of the cross-member, when other suppliers do not. 4) With all the well thought out mounting features of this product, again, why he is so against a gas filled shock in this application, when so many of us love gas shocks, in conventional use applications. A more expensive shock in this application, goes the wrong way ! This topic may seen trivial, but needed to be addressed in depth, once I got into it, finding out the little details. I attached the PDF install manual FYI. Happy Holidays to All ! SUSPENSION MAXX_SMX-SSB2520_GM 2500 KIT.pdf

Thanks Pryme. 64BAwagon posted if the SG-III can display current Allison gear. I got a reply back from the mfg. yesterday that they will look into it. I looked at every std. & the X codes available in my device, and on their website, and only found the "Recommended Gear" choice, that stays at displaying "Neutral" and never changes. Other Allison in motion choices are Input RPM (from the crank) and Output RPM to the driveshaft. These DO function. That digital code info must be available somewhere in the ECM or other control module, to control the shift points.

It has three pages of 9 monitors to customize. Can see the 1-2-3 page selection under the engine torque display.