Another JR

Victron’s Orion Smart dc to dc chargers are well built, have a lot of adjustability of the charging characteristics and the engine running detection logic and charging threshold voltages, and they don’t need a separate signal to tell them the engine is running. They cost a bit more than the Renogy. The Orion Tr Smart 12/12-30 non-isolated 30 amp charger is $226 from PKYS.com, who provides excellent customer support. I have no affiliation - I’m just a satisfied customer. If 30 amps is sufficient for you, it’s a great product. Also, you wouldn’t have to bother with finding a switched 12 volt D+ signal to tie into - you just need the two main wires and the software decides when to turn it on based on your settings. However, you will be able to get the Renogy installed and it will do the job (with 10 more amps of output). A time delay relay on the control circuit can mostly address the start battery initial recharge current concerns Sheath mentioned in normal operation. The Renogy would make your system less tolerant to an alternator failure, but those are pretty rare, you get indication, and you just need to remember to immediately shut off the charger one way or another to avoid draining the truck battery. If it was me and I felt 30 amps was sufficient and I could return the Renogy for a refund, I’d go with the Victron because of its more sophisticated controls and easier installation, but the Renogy is not a bad choice if you are committed or need the 40 amps.

The Renogy chargers do not have that capability. They have somewhat adjustable output voltages, but on/off is simply controlled by the D+ wire.

My Victron dc to dc charger has a programmable delay after engine running is detected to allow higher initial recovery current for the starter battery. On chargers with a hard wired trigger from a 12 volt circuit, you could achieve the same effect with a time delay relay.

2021 3500hd slt cclb srw, gas, camper springs (one step lower than plow pkg springs),18 inch stock wheels and stock Michelins. Unloaded my front axle weight is 4440 and rear is 3260. Unloaded I run the front at 55 and the rear at 63. At 62 my tpms alarms. When I have my 1800 lb camper on I run the rear at 67. Almost all the camper weight is on the rear axle so my rear axle weight goes up to about 5000. The ride is significantly stiffer than my 1/2 ton suburban, but is really quite smooth and not at all objectionable for such a heavy truck. On the highway it is a pleasure to drive. With my camper installed I still am not on the overload springs so the ride should be the same as a 2500. Payload rating is 4054 so I’m only at about 1/2 load. I did not need the front camper springs option I ordered, and I plan to install the base springs in May or June to soften the front a little. It’s fine with them, but the front is slightly stiffer than the rear with the camper on, and I think the suspension will be ideal for my camper load with the base springs.

When I test drove the trucks, I could definitely feel a difference in the stiffness of the ride and transmission of road roughness between 18” versus 20” tires. Of course, this was on empty trucks with max tire pressure. I chose the 18s for the smoother ride. Both tire sizes are smoother if you set tire pressure appropriate for the actual weight.

There’s a good reason the manual recommends not towing in the break in period, and it is primarily related to the differential. Heat is part of it but really a by-product of the break in process. However, it also aggravates the conditions during break in by thinning the oil. When the differential ring and pinion are new, the gear tooth contact area is very small, creating very high contact pressure. This causes oil film breakdown and surface wear, which eventually wears in the contact point, spreading the tooth contact pressure and reducing the local surface stress. If the differential is highly loaded before this wearing in has been allowed to slowly occur, the high local contact stress can cause spalling of the tooth surfaces at the contact point. If spalling occurs, best case it will cause a noisy differential with reduced life, and worst case it can cause tooth failure due to the created stress concentrations. instead, you want to run the differential lightly loaded until the gear contact patches have worn in to some extent, spreading out the force and reducing the contact pressure. Once this has occurred to some extent, the gear teeth can withstand the higher load assocIated with towing. GM has recommended a particular minimum number of miles for this. More is better.

Diyer2 - can you explain the basis for your answer? Since the L8T is a relatively low compression engine, I was about to answer the opposite, but I have no actual test data. Maybe you have experimented?

My neighbor took delivery of his 2021 3500 Duramax within a week or two of delivery of my 3500 SLT gas last April. He really likes the truck, but it has been down for the last two months due to a transfer case control failure that locked up the wheels suddenly on the highway and destroyed the transfer case.

Why has this thread not been moved? This engine is not on the HD trucks. Moderators???????

Aside from the discussion of whether you need the diesel and what issues it has, I am really happy with my 2021 3500hd gas truck. I hope you are just as happy with your new truck.

I suspect that package costs more than the dealer would charge you for the number of individual oil changes allowed under the package. These kinds of packages are almost never a good deal. Instead, they are an additional profit/commission opportunity for the dealer and salesperson. The oil change takes exactly 8 quarts and the filter is a standard filter type that is around $10.

If the truck sits only 1/2 inch higher in the rear it has been altered. In the stock configuration it should be 2 plus inches higher in the back when unloaded. I have a 2021 3500hd cclb with stock suspension and wheels/tires. When I install my popup camper, which puts 1600 lbs on the rear axle and 100 on the front axle ( I weighed it), the rear drops about 2 inches. The rear is still about 1/2 inch higher than the front with the camper on. The overload springs are not engaged at that load, so a 2500 would be the same. if you are approximately level unloaded, your 1600 lb 5th wheel hitch load is going to cause your truck to be about 2 inches lower in the rear. It will be close to the stops at that point.

I don’t think it’s normal, but they all make that sound.

Curt makes wire bundles with connectors compatible with GM connectors. You end up buying a 7 or 10 foot wire harness with connectors, and don’t use the panel mount trailer connector that comes with it. You separately buy the oval panel mount connector, and the Curt harness plugs into the back of it. The other end of the harness had male and female connectors wired in parallel and those connectors insert between the bumper connector and its harness. 7 foot harness Curt 56070 Panel mount oval connector Hopkins 40974

I agree. Sounds like you broke something in the 4wd system rather than the transmission due to making repeated tight turns in 4wd in a high tire traction condition. Unfortunately it’s not really built for that.

My OEM camera, which is the same part number as my tailgate camera, was about $100 from one of the on line gm parts dealers. The cable from Pasternack was $36 shipped. The hard part was fabricating an enclosure. All the ones i found on line were huge. I used a pvc plumbing fitting. The tailgate camera angle is very close to 45 degrees down, so a 45 degree ell worked well.

Buy the OEM camera, get a cable from Pasternack.com, figure out how you want to mount it. Here is my installation on my camper:

I was simply responding to the person I quoted, who said he didn’t think his truck could hit 20 mpg even coasting downhill. I understand I consumed extra fuel climbing on the way up.

I had a trip mileage of 24.1 returning from Mt Rainier to South of Seattle last Fall. Quite a bit of coasting downhill in the first third of the trip and a lot of 50 mph driving.

I did not experience extended cranking during a recent cold stretch here in the mid 20s F (that counts as very cold here in the Seattle area). So the threshold must be lower than that.

I get around 17.5 on the highway doing 65-70 on rolling terrain when empty. With my 1800 lb popup camper, I get 14.5 to 15 on the same terrain same speed. I have the stock 18” wheels and Michelin tires. No suspension mods.

When you first open the door do you hear the fuel pump run to pre-pressurize the fuel system?

I have weighed my 2021 3500hd gas and the front axle weight is about 4500 lbs. A diesel is going to be about 5000 lbs.

Leem offered a good technique: lube the bushings with spray one at a time driving in between until the noise stops. I don’t know if wd40 is a good choice for the materials. I would have guessed silicone spray would be better for the bushings, but I really am guessing. Maybe Leem researched that.

Sounds like a shock or bushing noise. Unlikely to be torsion bar.