Ok, so here’s a recap! First off I will share my cat scale ticket.
Yes, I’m over the 19,500 GVWR….I didn’t kill a school bus full of nuns, or anyone for that matter.
Technically, I’m under GAWR for both front and rear. Rear is 14,706 and front is 7k. So I had about 800 lbs under GAWR. I’m under the max weight for the tires and wheel capacities and from what I have found the GCWR had a 30,000 lb option back in the day for high towing capacity package, which fit the criteria of my truck. So I am under 30k.
I do find it interesting that when ford came out with the F600 they reinforced the frame right behind the cab. With the frame stretch I have 2 giant C channel frames sandwiched together during an overlap. So while there may be other concern spots I know that this isn’t one of them. Lastly, this is with 80 gallons on board and the load did get lighter as we went along.
Chassis and suspension: it flat out didn’t care. The suspension didn’t handle funny, it didn’t have a ton of sway, etc. I feel confident in the chassis at this weight level all day long.
That’s probably where the “it didn’t care” ends.
Engine seemed to have more then enough power to accelerate but EGTs became an issue. First I had another tune on and it was smoky as hell. I went to a medium tow tune and it cleaned it up nicely. EGTs we’re better but still an issue. My turbo setup isn’t a bolt on ordeal and is known to be the best at EGT control and at 20k lbs gross it is never a concern but at 29k I had to watch it.
Transmission: temp wise, it never got hot and handled the load just fine. Gear option wise it’s severely lacking. At 20k lbs I can live with a 4 speed 95% of the time. At 29k it really needs more gear options and the reason being is EGT control. In certain situations I’m pulling a grade and will get up to 3100 rpm, it’s time to shift, and it drops 1k rpm. At 2100 rpm it’s not moving enough air going up hill at that load and EGTs become an issue. So you let it sit at redline and pull the grade at that speed. With a 10 speed it will drop from 3100 rpm to 2750 rpm and I think the 6 speed would be like 2500 rpm vs 2100 rpm. It’s much easier to continue to accelerate at that rpm while keeping EGTs in check.
All this was done at 4K-7400 feet in elevation and in 85-105 degree heat with the AC on full blast for hours on end.
When I did 28k it was 45 degrees out and 1200 elevation and it pulled grades like a champ.
Braking: it did stop the loads and I had to get used to it as I got them hot 2 times but once I got control of downshifting it was much better. It could use an exhaust brake for a much more confidence inspiring braking experience but I also wasn’t fearing my life there.
I will not be doing the aux trans. I think it’s just a bandaid and adds too much weight. I think the real answer is a 6 or 10 speed. It probably isn’t feasible but figured I’d mention it. My main complaint was gear options. I did email US Shift and they are working on the 10R140 stand-alone harness but it’s about a year out.
My buddy asked me if 29k isn’t efficient for these 2 rigs, as in, is it lighter with a F350 dually and gooseneck and I don’t think it is.
2022 Ford F-350 dually 4x4 is 8,133 according to fords site.
JK and H3 combined is 13,500
Big Tex gooseneck to handle that weight is 6,200
Your at 27,833 before people and road trip crap. That 29k includes that I have 80 gallons on board during that weigh in. So I don’t think it’s inefficient in terms of weight.
So as a whole would I do it again? Yes, I would. The truck handled the load fine in most situations. I went as fast as 73 mph and as slow as 34-38 mph up some of the grades at 7k feet when it’s near 90 with terrible air quality due to fires (not sure if that changes air density)
I had one situation I will never ever do again. I pulled off to a passing shoulder and had to start moving at a stop going up hill right near the summit. I had to keep it in first at like 25-28 mph until I hit the summit. If I didn’t stop and just wait for the passing lanes I probably would have never gotten into 1st gear and maintained 2nd at 35 mph or so.
I saw a 2004-2005 duramax with its hood up on the side of a grade…so I’m glad I didn’t overheat lol I saw many ram 3500-4500s pulling 3-4 cars and I always wondered what they pull like with probably 30-35k gross. They were on flat sections at 4K feet but I would love to see how they would do going up the Sierra grades at 7k + feet.
Rear axle was hit with an infrared temp gun and never saw over 175 at the pinion.
Lastly, here are two slips, the truck when I got it and the weight with the t case, 4x4 swap, new rear axle, aux tank with fuel, winch, some spare parts and heavy ass ramps in the bed and 3 tires I needed to bring to the dump. I’m assuming a good chunk of the weight gain is unsprung weight and not weight that the frame and suspension have to hold up.
