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1999 C7500 Dump Truck Towing Capacity

Willie B

Senior Member
Joined
Jan 2, 2016
Messages
4,040
Location
Mount Tabor VT
Occupation
Electrician
A gas engine falls weak on torque. It needs gear reduction to power a heavy truck. I found mine had 5 X 2 rear gearing. Up, or down hill I was never very high in gear ratio. The engine screamed 3000 - 4000 RPM all the way. This is not good for fuel economy, and a lesser engine won't survive it long. The GM truck engines 366 & 427 were built to haul. Massive crankshafts were forged from steel, not of cast iron. the cooling systems were high volume, big ports, big pumps, dual thermostats, and VERY big radiators! Cylinders were tall, as were pistons, and an extra oil control ring was equipped.

I could brag all day about these engines........until we discuss fuel economy.

I fear newer engines were not engineered for the same level of longevity.
 

Steve Frazier

Founder
Staff member
Joined
Oct 30, 2003
Messages
6,599
Location
LaGrangeville, N.Y.
gvwr is what the truck its self is sold as being capable of handling . gcwr is what you license it for to be legal for the gross weight you want to haul

I'm familiar with what GCWR is and that's the search term I used. GCWR is often listed in sales literature as a selling point. The page I referenced was a review of the truck back when it was new and that was the information they listed. The laws regarding that number seem to vary from state to state, in NY if you were involved in an accident over the manufacturer's recommended limits you'll have a lot of explaining to do in the courts and very unlikely to come out with much more than the clothes on your back.
 

DMiller

Senior Member
Joined
Feb 21, 2010
Messages
16,432
Location
Hermann, Missouri
Occupation
Cheap "old" Geezer
This information is what the state level DOT personnel are currently using to get at the NON CDL considered commercial drivers for landscapers, for hot shot services, for short run shippers that use no DOT information as try to slide under the wire.
 

Willie B

Senior Member
Joined
Jan 2, 2016
Messages
4,040
Location
Mount Tabor VT
Occupation
Electrician
I've always wondered about where I'd stand in a truck check. Never found any published GCVWR on either GM medium duty I have owned. I have carried 30 750-800 LB concrete blocks plus a 1500 LB boat many times for the antique tractor pulls. With trailer that is 30,000. Add the 12500 truck, that's 42500 combined weight shared between trailer & truck.
This load mostly North / South on reasonably level Route 7. It did struggle on even gentle grades with the 427 Gas. As for keeping it under control, no problem.

Just a guess, these trucks are fitted with a great variety of bodies. They outfit them with a wide variety of suspension, and drivetrains Owners manual for the 1976 C6500 mentioned tandem axles as a option. GVW varies all over the place. In an earlier year, each state had different laws. Each truck will have a different tow rating.
 

DMiller

Senior Member
Joined
Feb 21, 2010
Messages
16,432
Location
Hermann, Missouri
Occupation
Cheap "old" Geezer
Current mfg build sheets include GCWR on them, not hard to dig up the old GCW lists as found with the DOT boys here. They were in the old Owners manuals as to the numbers and had to have Final Completion company (Body Installers)sign offs.
 

Jmiller26b

Active Member
Joined
Nov 24, 2020
Messages
30
Location
Missouri
You guys are awesome and are a wealth of knowledge! Thank you all for your responses! After reading your comments I think I may pass on the truck and look to go with a newer diesel instead...even though it seemed like a good buy. The fuel economy with the diesel would be a plus because I plan on loading the bed full of logs and hauling them off of the job as well.
 
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