Chuck FB

Have you looked at all four shocks for signs of oil seepage. Also with just the truck on its own have you experimented with driving over speed bumps in a parking lot to feel the reaction the truck has, if the front or rear of the truck tends to pogo along after the bump indicating the shocks are not capable of controlling the suspension properly. I can't claim your stiff front torsion bars are causing any of this issue but from a logical ride quality stand point I can't see them being helpful. As was mentioned if you were able to get the trucks axle weights on their own and then again with the trailer hooked up to see how much weight is coming off of the front axle, how much is being added to the rear axle etc might be of help and perhaps your setup might benefit from a weight distribution hitch even though its not seen as a "big" trailer.

Ok that makes sense, if you know the contractor or contractor company and if they are local, you might be able to track that same truck down if you can't easily find another one with the same spec. Of course depending on your local dealers they may stock some bare bones two wheel drive contractor trucks. As I have mentioned before that around here in the last number of years they just stopped bringing in two wheel drive trucks as the average joe has figured out they want a 4x4 for the winter and that goes for the half ton or the even smaller mid sized truck segment.

You need an official looking uniform and printed on your shirt "Inspection Osifer" If GM would have specs on the diameter of each rated torsion bar size, that would make it too easy of course. I am guessing that you found out from GM what the sticker part number is for that #4400 torsion bar and you saw it on that one unicorn truck and no measuring instrument was available.

I've always wondered what the long term effects would be on shocks with no protection on the rod, on a front axle there isn't the same amount of direct crap flying straight at the shocks as there is on a rear axle. Its one thing on paved roads that never have winter sand/salt spread on them but can't somehow see a bare rod doing very well on gravel roads and winter roads spread with crap. Has anyone reading this ran a bootless shock for some years to have experience in such conditions ?

Epsilon, double check 9th gear ratio as my searches ( based on info some site compiles ) shows it as 0.68 10th and 9th gear ratios are so very close going by the tach, in my mind too close but it is what it is and expect there is a reason for it based on the various clutch packs engaging to flow power through certain gear sets that are used in combination for other gear ratios as well it what I suspect. Comparing the upper ratios ( based on the info I have ), 9th in the 10 speed is virtually the same as 6th in the 6 speed. Then 8th gear in the 10 speed is the same as 5th in the 6 speed. Another interesting item I noted is that while the 10 speed does indeed have a direct ratio for 7th so I assume no gears being used but straight power through the trans, the 6 speed does not have a direct drive ratio. Another item that I know in the past with 3 and 4 speed transmissions, which was a real downfall to moving a load in reverse and that is the ridiculously fast reverse ratios. So in this example the 10 speed has a 4.54 reverse and the 6 speed has a 3.06. That is almost a 50% gear reduction in the 10 speed and when it comes to backing up a trailer in soft conditions or up a hill that would be very helpful.

That is the downside of a mechanical fan, an idling engine isn't turning the fan over fast enough for one thing and at least traditionally the bi-metal spring is set on the high side temp wise so does not lock up the fan clutch when one would desire it to. This reminds me of being in Death valley one day years back in July and by far the hottest temp I have ever been in ( I live in northern Alberta after all ) as it was 118 according to the part office. I was driving an older half ton pickup that I had swapped in the thicker core factory rad that fit the truck as it was meant for a 3/4 ton but I still had the half ton less aggressive fan ( the drive is not strong enough to drive the deeper fan of the heavier trucks ). However I didn't want to push my luck so was not using the air con at all and only the cab fan ... yeah, was I ever having fun LOL. So when I would come to the next place of interest I would turn the engine off as I knew it was not going to get any cooler sitting there idling and in fact because of the rad and not using the air con the engine temp actually stayed very good considering and I certainly was not pulling anything. When I pulled in at Bad Water I noted that most vehicles were sitting there running and were cars or mini vans and they all had electric fans and of course they were running their air con and every vehicles fan was howling at full tilt. Also when I had put the thicker rad in I had bought an aftermarket fan clutch hoping it would kick on sooner than the factory one but with testing of covering the grill at home to force the engine to warm up to kick the fan on, it was no better. So what I did being that it was a cheap unit anyway if I wrecked it I bent the bi-metal spring around at the end to change its effective length and preload and was able to get it dialed in to where it would kick on sooner but not at normal experienced operating temps as a locked up clutch is one power hungry/fuel hungry item when its not needed and would cause premature failure of all the pulley idlers and water pump shaft etc anyway. Now perhaps your clutch is engaging but with just sitting idling it may not have enough effect, next time its in that situation try slowly revving the engine up some to see if you can detect if the fan clutch is engaged by the sound of the fan noise. Your idea of adding an aux electric fan may be the the answer and hopefully the alternator has the ability to run it without undue stress at idle.

Which direction are you driving and do you happen to know the two approximate points by some reference easy to find on a map ?. Also what time of the year was that as you mentioned a cool temp ?. I know there is a certain amount of elevation change even within the city on 15, well that is if I could ever figure out where the city officially is as it seems to go on forever !. I've only been through it once years ago but also north of and south of the city the elevation goes up at some point as well.

I am curious as to what 3/4 ton to 1 ton you were comparing the ride of. I would imagine over the years there may have been main leaf pack differences between the two models and part of that may have depended on what GVW they gave the 3/4 truck and made a lighter pack for it. Currently there doesn't appear to be much difference with a GM 3/4 vs 1 ton, they shorten the lower overload a bit and then add two thin leaves to the upper overload which don't come into play until a lot of weight is on the truck to get those upper overloads to touch the frame pads. Also it would depend on which front torsion bars were optioned, and even what tire size and type, and pressure was being carried. Now a Ram for example is a very different beast going from the 3/4 to 1 ton as its a soft coil spring vs the beefed up leaf spring in the 1 ton and that gets talked a lot about as per the very different ride between those two trucks. I took a look now to confirm if the 3.0 diesel can be had with the 3.73 axle that comes with the max tow package and that is definitely the case, however and has been all along that the gas engines jump up from the 3.23 to the 3.42 ratio when they are equipped with max tow. The issue is if one wants the two speed transfer case and only certain engine and trim levels allow the max tow and two speed transfer case to be paired. I know the 6.2 engine can be in a high country or LTZ but the Canadian website anyway doesn't spell that out at the end, nether does the 3.0 diesel in the high country. Unless the US website is more clear, that would be a dealership question to someone who can spit out all the RPO codes etc that GM will mate together ( and yes, Newdude may have all these answers in his head with what GM will or won't combine as a desired list of options ).

Your right, I just call them GM axles as per the truck manufacturer but yes they are AAM axles. At one point GM established their "GM corporate" axle division I will call it to standardize their axles between their sub brands ( GM, Chev, Buick etc ) and then they spun off that division to investors and who are they ... AAM, makes a persons head spin as Detroit, Allison were also sold off from GM. So going back to my questions, that's good to hear they have magnets in both diffs or should say the diff covers and certainly the dealership method of sucking oil out of the front diff isn't going to clean that strip but is a short cut to doing the service work. Bolt torque wise, it would be nice to know what they intend for those cover bolts as I've only speculated that they don't overly torque those cover bolts based on their size to be careful of the gasket but red loctite seems a little out there for sure and yet somehow they must have had a reason to go that aggressive on the thread locker compound. Not that I have touched the pan bolts for the trans yet but 80 inch pounds is pretty easy to surpass and certainly the 44 inch pounds for the two filter bolts. With piddly little bolts into aluminum one just doesn't want to make errors "$$$". Most of what I work on I don't use a torque wrench unless I feel it is critical or touchy because of trying to clamp down gaskets evenly, and things like head bolts and diesel engine valve train adjustments etc or working on motorcycle engines with again that aluminum theme and piddly little bolts. That cover certainly looks a lot more robust then the factory tin hat on both diffs, factory tin is ok until one gets into rocks in off roading without enough clearance, but that's where I am banking on my "Z71" skid plates to protect me

Hopefully it should last a long time if your able to keep it in that condition and adds up as to why they chose to reuse your ubolts. Had that truck been around where I am and used a lot as per an oilfield truck for example pounding up and down our wonderful salt/calcium winter roads as well as gravel roads all summer, your underside would look very different. I just hated to buy a new truck to put on our winter roads but the alternative was someone elses over priced pile of rust that was not take care of with any proper maintenance and no warranty. I've drowned most of the underside of the truck and inside the frame and rocker panels and the double wall of the box in fluid film and will see how that goes, that will be a yearly repeat process and a very expensive one as I blew through a lot of product and its a lot more expensive up here to buy.

Is there any provision for adjustment from side to side like typical headlights in the past were designed like or is there only a vertical adjustment. I haven't had reason yet to adjust my lights but I also haven't used it much at all in the dark either, however I did have someone flash me right after I bought the truck and found that odd as its not like I had any weight of consequence in the truck or had modified anything which I did slightly after as per doing a slight adjustment on the front torsion bars which did raise the front end slightly. The adjusters I do see which would be for up/down are quite easy to access, be it a 6 mil bit on a 3/8 extension or a typical 6 mm allen wrench, yes it has the Philips drive but it is plastic after all and pretty dinky looking.

So I gather you've drained both diffs now and I had a few questions relating to the process. One item was if you had found out what the gm torque spec is on the cover bolts as I expect its rather critical not to over torque because of the reusable gasket to avoid crushing it and causing a leak. Just speculating maybe that is why they used the loctite to hold the bolts in place as the torque value is not very high ... but again I haven't a clue what their torque spec is. Did you in fact reuse the factory gasket or throw in new ones. I had bought a rear gasket for my truck just to have on hand and when I priced out a front gasket it was stupidly priced here in Canada and passed on that but asked them what their shop does and the partsman who had been a pit tech to begin with said they sucked the front diff out rather than even pull the cover. He had no idea if there was a magnet inside the front diff because he had never pulled one off and obviously its not as if I could expect a young partsman to have all the answers. I expect you can fill in a few blanks to what I am curious about. Now if GM had kept the drain plug on the rear diff that would have been handy and not sure if at one time if they had a drain on the front as well.

I've forgotten what year your truck is but there must not be much rust on the ubolts or rock damage on the exposed threads for them to be reused. I thought perhaps GM would just replace them as a matter of course and call them one time use hardware but I guess that is not the case, yours were more than likely in good shape then. I believe they do call the spring eye bolts one time use though and makes sense why they tossed them.

The good part is its stopped the noise and would not surprise me if lets say it was a bushing issue and was more cost effective to toss the old springs vs having the bushings pressed out and new ones pressed in !. By the way can you tell if they used new ubolts and associated bolts for the ends of the springs as well ? This noise issue reminded me of a one ton dually owner from Ontario, I believe its a 2022 Chev with the gas engine and he hauls a full size camper. He recorded the noises it was making in a rough section of a camp ground/road as the camper was swaying from side to side and it just creaked and groaned something awful. Then months after that he had a spring shop add some leafs because he was towing a trailer behind and wanted to boost up the rear some as it was sagging excessively. Now his noise is gone or or greatly so and I don't know if they pulled his packs to perform the job or what but something changed and he doesn't know either, just that he doesn't have to listen to that awful noise. Oh the mystery ....

Has anything been said or could you see any difference between the old pack and the new pack. It just seems insane that it takes replacing the spring pack to repair the noise issue and yet I assume there is nothing mechanically wrong with the old springs ? What blows me away is that leaf springs have been around for a very long time and until more recent years they would stack the leaves up and bolt them together without any fancy spacers in between and for that matter no fancy slipper pieces snapped into drilled holes at the ends of the leaves.

I too did not try to note if there were any differences in length of the main spring pack springs as per the three springs under the spring with the eye bushings, but what I did see and your photos also show this is that the bottom tapered overload spring is different in length as in shorter on your new truck. I realize your photos are not taken at the same angle on each shot but I would say from looking at my spring pack ( and again mine being on the gas one ton ) that my spring pack lower overload tapered spring looks to be the same length as your new max tow truck and my upper overloads are also two leafs. It would not be that surprising if they use the same spring pack for the gas and diesel versions in the 3/4 ton, as well as the different spring pack with the upper overload style for the 1 ton version of gas or diesel since the back of the trucks weigh very similar. The front axle is where the extra weight of the diesel sits and why the standard torsion bar diameter is larger and rated higher on the diesel ( unless one gets the gas truck with the snow plow prep ). The max tow package does cost somewhat less than buying a 1 ton rated truck, it doesn't give quite as high a weight rating but if that doesn't matter then its a mute point, and not sure about Ontario licensing and if that lowers your rate over a 1 ton. I suspect the reason why the dealers up here tend to bring in more 1 tons and especially if its a crew cab, is customer demand and part of that would be oil field and forestry, and farmers as well just buying it to get more payload since the price spread isn't that much and as I pointed out before the insurance rate tends to be a bit lower.

Which province are you in or purchased the truck in as I am surprised such a unit even made it into dealership inventory assuming it was a dealership order vs a special order someone backed out on. I won't pretend to know the various licensing issues that some provinces may have over others but I am in Alberta and the 1 ton single wheel typically way outnumbers the 3/4 ton on lots and tends to be so lower end trim work trucks that are spec'd as a 3/4 to get the cost as low as they can. Licensing would actually cost more here if its licensed as commercial and going across into other provinces the higher the GVW I believe but if driven personally it makes no difference. Just seems some of these GVW levels have more to do with some of the states that automatically throw a 1 ton into a category if used commercially that the driver has to hold a commercial drivers license, yet some states have a lower fee for a 1 ton plate over a 3/4 ton which makes no sense either. The only thing I have picked up on so far looking at a 3/4 vs 1 ton single wheel spring pack aside from the obvious upper overload pack, is that the bottom leaf which is an overload in a sense is longer on the 3/4 vs the 1 ton. If your ever at the dealership and looking at trucks and it does help to compare with the same tire size as a visual point of reference or you can use a tape measure, you can see if your bottom tapered spring has the same length spring forward and rearward of the axle vs other 3500's. I never noticed that until I had bought my truck and was comparing the packs of a 3/4 that sat near mine, that it really was different. Also the bottom leaf is not centered from front to back, more spring sticks to the rear of the truck although the 3/4 has a similar theme but longer in both directions. I never have heard any concrete info on torque management, I have heard said that the 3/4 had it or more of it in low gears vs the 1 ton and if so I would only be guessing to say they would logically tune yours as a 1 ton since its got the heavy rear diff.

Speaking of winds and because of having the fuel mileage readouts, I find that even a stiff side wind or even slightly to the rear of sideways will still knock down the fuel mileage and can be on the same stretch of highway I go on frequently in the same direction. A direct tailwind is great but coming around too much to the side seems to have a negative effect, obviously a head wind is a killer. Still though, getting 17.5 to me is quite remarkable over what historically a truck not this high and heavy in a two wheel drive could dream of getting years back no matter how good the conditions were or how grandpa like one drove ( the proverbial egg under the foot ).

Speaking of actual realistic fuel mileage and as you pointed out 19 seems to be about the achievable number, then as you pointed out as well with the 25 mile being so easy to manipulate and can give wildly impressive numbers by way of elevation drop or a high tail wind. I had mentioned in another thread of a lady youtuber who claimed her 2024 6.6 duramax gets 27.1 and then lately she happened to scan over her dash just enough that I caught where she came up with the number, it was listed as her best 50 mile. Granted a 50 mile setting would reduce the bs, its still not long distance driving with typical variables. The odds of getting 27 with a 6.6 duramax on a long drive at even a careful highway speed would be quite something. By the way I have been in Estes or as I mistakenly group it together and refer to the area as Rocky Mountain NP as per the loop road and its getting a ways up there all right, that would be a drop from 12000 feet down to 5000 in that case so a 7000 foot drop .. maybe could break the 100 mile per gallon mark !. Also was going to say that last year I had bought some slightly used factory wheels from a guy who has a 2022 duramax and he was making some rather fantastic fuel mileage claims on his duramax because he had it deleted ( its legal enough in Alberta that shops do it all the time on pickups and highway tractors ) and he claimed there was quite a noticeable jump in the fuel mileage as per numbers like 23.5. However he was going by the dash and I always wonder in the back of my head if a software programmer could if they wanted to, to manipulate that data to make it look even better. Never the less there would be no more fuel thrown out with regens and no more restrictions with all the crap in the exhaust and then tuning/fuel timing would play a part in it as well. I don't doubt there is potential under the hood of these emissions strangled pickups to get better fuel mileage if they reworked them right from the factory, never mind have a fraction of the issues do deal with through the life of the unit that the diesel industry struggles with now.

The reason I was curious about the highway is I had been on interstate 94/90 once years ago just driving through from Minneapolis area and on down past Madison and south, its years ago now but in my mind I seemed to think of the drive as quite flat but I covered a lot of ground and its easy to forget certain things. The main problem was the awful road conditions for the first ways from MN due to a winter ice storm as it was in the middle of Dec and miles of traffic going no where in the middle of the night on the freeway but once I got out of that mess the next morning it turned into easy driving with no snow or icy roads to contend with ( other than the touristy pass over the Smoky Mountains ). I've not taken the effort to test the premium fuel up here and I am told its a bit of a coin toss if it will have some ethanol or not, I only buy small quantities of it for running in chains saws, trimmers and a small generator. But as to regular grade ethanol free, I have never heard its a thing up here but of course was all ethanol free some years ago but leaded fuel instead.

You wouldn't by chance be referring to interstate 94 or 90 would you ? For sure that is a pretty mild elevation, no its not like driving the coast but a far cry from an extreme of mountain country in Colorado plus the insane altitudes and sucking for air or certainly a naturally aspirated engine is. I see a few on here or other places on the internet talking about being able to find non ethanol fuel so I wasn't sure, I imagine its a state by state thing and unfortunately here in Alberta with regular I suspect most of it has some ethanol in it and therefore reducing the fuel economy some. As my truck has that fuel economy readout that records from the moment the key is cycled and then driven and deletes itself when the truck is turned off, its easy to tell by it that when I for example drive back from town to home its starting out with a warmed up drive line and counts up to better fuel economy numbers far quicker which indicates the truck is able to use less power right off the bat due to less friction vs a cold start. While not exactly fair, yes it would be possible to have the vehicle warmed up from a prior distance before starting a mileage run ( no doubt the EPA fuel mileage testing is done just that way to get all they can out of the vehicle to pass ! ) as even that would bump up the mileage test a little. Not sure how the 6 speed and engine combo is computer controlled compared to the 10 speed but after my truck was past its break in, I did what amounts to a couple of different episodes of a zero to ground speed limit runs to see how the truck reacts as well as anything that might show up by pushing it like one would be doing towing. I did not actually look that closely at the tach but I don't believe it was getting anywhere near the redline before its shifts on its own accord, and boy does it show up as to how the computer pulls power drastically at the moment of shifts to protect the transmission under full throttle, one dead power shift after another and so many shifts as well being a 10 speed which explains why it does not impress speed or time wise in lets say a 1/4 mile. Of course I am little concerned with that, its not a sports car after all !, but am impressed that it is tuned to protect the transmission clutches vs slam shifting.

I did not think these trucks would be able to achieve that type of fuel mileage at that speed. Is that section of road quite flat and at what elevation is that at ?. Also do you know if the fuel your using is non ethanol or if it has the typical 10% or whatever it is that they throw in. What is your trucks 25 mile "best" reading, while that is definitely a cherry picking number I'd be curious what it shows as mine lately for whatever reason of I would guess a tail wind and maybe driving slower jumped up to a 21.2 reading in the 25 mile. I'd be blown away if I was able to reproduce that on an actual drive. Having said that I have yet to be on a drive longer than a 50 mile drive from point A to B and with a couple of stop signs and grades to climb as well so not a good test for best fuel mileage. Also and expect you have noticed this as well, right out of the gate from a cold truck the fuel mileage is in quite a deficit and as the miles accumulate the mileage keeps increasing slowly as a cold driveline and a cold engine even in summer time temps takes a while to warm up and lower the initial friction/drag. It would be interesting for you to drive the same route with the same weather at 60 mph and see the difference, you may even break past the 20 mark !

I imagine your winter ( which is probably more like our normal summer temps ) would be kinder to the temps or at least control it better. In reading about humidity I haven't come across proper information to say one way or the other if its a net negative or positive on engine temperature but it has effects with the actual air density as in decreasing air density with high humidity and the obvious which is your high ambient temperatures are not where its at for cooling, or power for that matter. Oddly the 3.0 diesel from what I am seeing on a mechanics videos is set up to have stupid high trans temps at a minimum as well, yet the gas counterpart half ton is designed to run a lot cooler when driving empty. Doesn't make a lot of sense to me why they are doing that but GM must have their reasons ... or its EPA pushing them. If your able to get 14 at what I assume is still a fair pace down the highway, that's all one can expect from a gasoline truck with the shape of a brick. Only by going slower and a consistent speed and no head wind etc can one get into some better numbers.

That certainly seems to indicate the trucks system forces the transmission to hold a high minimum operating temperature although that type of ambient temperature is not helping at all !. Lately I was paying attention to what my trans temp would settle in at and of course its a different transmission and more than likely the cooling system and how its set for its minimum trans temp. I was in very different conditions than yourself as it was around 60f outside starting out in the morning heading to town and I noted that it took over 35 miles before it reached the point where it stabilized at around 145f and I was driving at around 60 mph. On the return trip hours later it was 75f out and the trans already warmed up from driving around town between stops and so it came up to the 145 a lot sooner and that is where it hovered around and again I was only doing around 60 mph. What it would do driving faster and in a temp like yours and the air con on full blast, good question. As to your average and best 25 mile fuel consumption, I'm guessing you wore a very light pair of shoes to obtain the 18.5 best !

You got me curious about that now, perhaps in part it was because I was trying to add Z71 to max tow and it would not do it, and while some lower trims will list on its own the option of "two speed transfer case" alone as a choice, that was a no go as well other than the 6.2 as I believe it can be matched up within the LTZ trim with that engine and two speed and max tow, as well as its High Country trim. Also I was looking on the Canadian site, not sure if there would be option differences between the two countries. I might have said this elsewhere on here but a neighbour had bought a used 2022.5 model year refresh with the 3.0 but its a GM elevation and his criteria for finding a used truck was to have crew cab with a front bench seat and the 3.0 engine, and to be sure to have the max tow with the 3.73. What he found had the short box and he ended up buying it even though he wanted the 6.5 box. What he had not realized through his want list is that he assumed it would have a two speed transfer case and only when he had it at home and was going through things he went to "try out" 4 low and realized it wasn't there. I already knew what he was leading up to before he said it, I personally feel GM has missed out on sales because of them going this route but that's just from my own view point, their bottom line may say different. My wording wasn't specific enough about the animal collision theme as I am sure your very correct on the fact that the vehicle is a mess and a very expensive mess to repair regardless of size. What I was eluding to is the passengers survival and be that not injured or much less so vs wishing one was dead in the aftermath or actually dead. There are so many animal accidents around here and its a sparsely populated area in the scheme of things and yet some winters there will be one animal after another plowed up by the snow plow on the edge of the ditch along the local rural highway. I've been fortunate in that I've only hit one deer with a pickup so far and was a small deer and caused relatively minimal damage in the scheme of things, but I've also hit two deer with tractor trailers and both trucks had moose bumpers on them but still managed to bend the bumper of one of the trucks and insurance doesn't like to pay out for that, or passenger vehicles for that matter due to the number of claims they would get.