asilverblazer

The size tractor you are referring to can EASILY be handled by a half ton truck. If you can't keep that load on the road with a new half ton, you shouldn't be driving anything other than a mobility scooter. It seems that everyone in this thread has a good grasp of the different weight ratings.

Sounds like improper fueling. Fix that first, the P0172 and P0175 codes. You've probably smoked the catalytic converters from running too rich. One of three likely problems (in no particular order): 1. Fuel injectors. 2. High pressure fuel pump. 3. Low pressure fuel pump. Perform a fuel injector balance test and check/monitor fuel rail pressure (high pressure pump performance) and fuel pump pressure (low pressure pump performance).

Proceed with caution, there are counterfeit parts... the new one may end up being worse than the old one. I'm not being critical of your course of action, just warning you not to assume that putting a new injector in (or any part for that matter) rules it out as the culprit of the problem. Be careful with the intake gaskets too. They are supposed to be replaced when you pull the manifold.

A couple things... 1. At the most recent oil change did the old oil smell of gasoline? Sometimes the high pressure pump leaks to the crankcase. I don't recall specs for fuel rail pressure but 700 seems low. 2. I would pursue injectors or fuel pump separately. You've done the injector balance test and the results do not indicate an injector issue. You can run the test as many times as needed to confirm that result. If you choose to replace any injectors do so one at a time with a genuine GM part. I would try the high pressure fuel pump first if the pressure is indeed low. I would not replace the pump and injectors at the same time, too many variables start getting introduced.

Pay careful attention to fuel pressure. A past thread with similar codes, went quite deep and it ended up being the high pressure fuel pump. Its a long read. Thread

For 'normal driving' the tire size doesn't seem THAT large. I would maybe consider a salvage swap for an axle with a more aggressive ratio. I would also have the pinion angle checked professionally because of the amount of lift. What failures required differential replacement? Why was the 'axle' replaced? Are the u-joints breaking or wearing out? Are the other parts breaking or wearing out?

I would have a new on hand - I would inspect the old one for damage and check wiring to it - if you are tearing it down to check the old one, might be just as easy to replace it while you're there. I don't have the actual diagnostic for it in front of me to confirm that a new knock sensor is the correct action for P0332. There is also an outside chance that something else could be causing weird engine "vibrations" that the sensor(s) are picking up as miss fires. If memory serves, bad motor mounts, loose components, accessory drive issues or other drivetrain faults such as out of balance tires even. None of these are nearly as likely though and I wouldn't consider until thoroughly diagnosing the knock sensor issue.

Depends on what the problems are. Driving style? Typical terrain?

Fuses, wiring harness damage?

1. What do you mean by "haven't really had much problems", either the truck runs fine with no check engine light or it doesn't. 2. Investigate the knock sensor first, the truck won't be able to adjust timing correctly without it. Poor timing can cause miss fires. Fix the EVAP line, obvious faults will complicate diagnostics.

I think those are both with in spec.

It took them over three weeks to fix a 'bad' battery? The battery probably went bad just like you suspect, in order to diagnose further they had to replace it. Battery replacement probably cleared all the codes and they were lost where to look next. No codes, no problem, come get your truck. What was being done during that three weeks?

Since when can GM not build a small block V8? 1. Failing lifters 2. Lifter bores 3. Misaligned main bores All within the last 4 years. If there was 1 thing in the history of GM that they could do right it was a small block V8.

Probably be real easy to find a 3.73 axle with G80 in it, bolt on and go. (Tune update of course.) 4.10 would be just as easy to do but harder to find. The 4.8 was never a torque producer, power only really exists spinning it fast. I'd select mods to compliment that, a higher revving cam (within reason) wouldn't be a bad choice. Top end kit, long tube headers, transmission cooler, gear swap, tune. Cam shaft selection would take the most careful thought. Lastly, depending on the cam maybe a torque converter. For towing, the transmission cooler I'd recommend if your truck doesn't already have it an electric trailer brake controller and good receiver hitch. Otherwise all the mods ought to make a fun little truck to drive around.

Has anyone tried adjusting the trailer brakes to see if any improvement can be had? It's not recommended but I always adjust my trailer drums to provide 'heavy' drag when spinning the wheel/tire.

Seems pretty common sense to me, a gooseneck and fifth wheel both place the trailer tongue weight in the same location... Camper dealers are notoriously poorly educated (dumb). Never take advise from them regarding what you can or cannot tow, you'd be better off to ask your neighbors cat.

No... but to be clear... Weight on what tag? The trucks tag specifies maximum weights that can be placed on/behind the truck. The trailers tags indicate the maximum weight that can be carried by the trailer and it's axles. The actual pin weight of a particular trailer can vary based on what you put in the trailer and where you put it. The key is that when the truck and trailer are loaded as you intend to travel to weigh the combination at a truck scale. You should get three weights: 1. Steer/Front axle weight 2. Drive/Rear axle weight 3. Trailer axle weight 1 and 2 cannot be higher than the corresponding GAWR on the trucks sticker. 1 and 2 cannot add up higher than the GVWR on the trucks sticker. 3 Cannot be higher than the trailers axle ratings on the trailers sticker. 1, 2 and 3 Cannot add up higher than the GCWR on the trucks sticker. To determine the actual pin weight that cannot exceed the 2865 lbs, the trailer would have to be unhooked and the truck re-weighed without it. The sum of 1 and 2 with the trailer, minus the sum of 1 and 2 without the trailer is the pin weight.

Above is the only other reading I found on the topic... Nothing I read seems to follow a path that results in replacing the switch.

Should be real easy, pull the panel off, unplug the switch, pull it off the panel. Reverse for installation.

I doubt they know much more than published information I posted, I'd be interested to do an actual diagnostic of Chadw90's condition to see what tests point to replacing the switch to get better performance. Then compare those same test results to your truck. In his case there was an actual problem (apparently) and would like to see if that is the same in your case. In any case, all we are 'supposed' to know is what ever the manual says.

I bet you could do just the bottoms, I've thought of doing the same myself.

In my case, probably all the above... It would be a misnomer to say I frequent job sites, but I do occasionally. Currently, the tires on my truck are Goodyear Workhorse something or others load range E. My gravel road, that's about 1/4 mile long is tearing them up. They were new when I bought this truck and I can't wait for them to wear out so I can replace them, I can't bring myself to be THAT wasteful.