GM Ends Medium Duty Production

[JESSE1]

Back in the '90's GM made a heavy duty model called the 3500HD. I believe it was rated at 1 1/2 tons. Had a solid front axle and 19.5" wheels. Never saw many of them, seems like most were used by utility companies. If they had continued building them after they came out with the Duramax and Allison trans they might have had a popular truck.

 

[Renze]

Ford has such a good driveline it keeps mechanics fully employed everywhere.

Ford has everything on their European models so good that it keeps mechanics employed... The latest models Ka, Fiesta, Focus, Mondeo, they all lack proper rust prevention because ford has been cutting corners. Their doors rot within 3 years from new, and you keep replacing stuff at every annual safety inspection... A 6 year old Mondeo has about the same resale value as my 13 year old Volvo, but all i replace are some suspension bushings when the 300.000 km are passed.

Does a frame have to be boxed to be strong? Never saw a freightliner or peterbilt with a boxed frame.

In Europe the most popular trucks/vans are the MErcedes Sprinter (the VW Crafter is based on the same frame, only differs in styling and engine choice) and the Iveco Daily. Iveco tells customers that they have a truck chassis "like the real trucks" and that their open C-channel frames dont collect dirt so they dont rust as quickly. However their chassis paint job is just shabby. Mercedes has a boxed frame, has a perfect paint job and coats the chassis heavily with wax after assembly.

Now the big noticable difference between the MB/VW chassis and the Iveco chassis is: the Iveco twists and badly hangs over in the corner, (yeah, just like a "real truck" ) and the MB chassis rides like a passenger car: no cornering hangover, perfect road behaviour. You dont notice you're controlling 5 ton with your right foot, which became a problem for some drivers when the model first came out, with the 184 hp V6 as they, because of the car-like handling, didnt anticipate on their center of gravity and weight inertia and ended up in the ditch.

 

[Builder]

Does a frame have to be boxed to be strong? Never saw a freightliner or peterbilt with a boxed frame. Resale value tells the story. When customers are happy the used price is higher and in greater demand. If it wasn't for the cummins dodges wouldn't have a hd line. Ford has such a good driveline it keeps mechanics fully employed everywhere. When mine is traded and GM doesn't offer a replacement it will be an International.

Yeah, I just went out and looked at my 33,000lb GVWR/60,000lb GCWR IH dump truck and it doesn't have a "boxed frame". Guess I better trade it in on an F-350 with a "boxed frame" so it can get the job done. lol

I'll make sure to spread the word on the big truck forums I belong to that they better get "boxed frames" on those bigger trucks right away. I'll also let them know boxed frames don't corrode as fast because they don't trap road salt like an open frame, too. haha.

 

[Diamondpilot]

Comparing a consumer versus a professional truck such as a 3/4 ton to a semi has no merit. The material spec, thickness, and design characteristics are totally different. Sure you can make a strong frame that is not boxed. In lots of ways they are better as mentioned plus they can flex slightly to prevent cracks. I see this on trailers all the time. The box tub trailers look great for the first 15 years but rust internally while the C channel frames do not look as sharp but last for ever.

The simple fact is GM can not jump into the 450/550 market with the current chassis they have for the 2500/3500 series trucks. Can they make a chassis that is capable of making it in that market? Sure, they are just late to the game.

Chris

 

[Travelover]

Yeah, I just went out and looked at my 33,000lb GVWR/60,000lb GCWR IH dump truck and it doesn't have a "boxed frame". Guess I better trade it in on an F-350 with a "boxed frame" so it can get the job done. lol

I'll make sure to spread the word on the big truck forums I belong to that they better get "boxed frames" on those bigger trucks right away. I'll also let them know boxed frames don't corrode as fast because they don't trap road salt like an open frame, too. haha.

I worked in the industry for many years, including frame design. The purpose of boxed frames on pickups is not for durability or hauling capacity, but to minimize vibration. A conventional open frame has resonant frequencies that contribute to customer complaints from engine idle, tire and driveshaft vibration. Stiffening the frame makes the vehicle much less sensitive to these kinds of disturbances.

I know that some manufacturers have touted the "tough boxed frame" in their advertisements, but that is puffery.

 

[Builder]

I worked in the industry for many years, including frame design. The purpose of boxed frames on pickups is not for durability or hauling capacity, but to minimize vibration. A conventional open frame has resonant frequencies that contribute to customer complaints from engine idle, tire and driveshaft vibration. Stiffening the frame makes the vehicle much less sensitive to these kinds of disturbances.

I know that some manufacturers have touted the "tough boxed frame" in their advertisements, but that is puffery.

Correct, and I was simply supporting this member's post that boxed doesn't mean stronger here:

Does a frame have to be boxed to be strong? Never saw a freightliner or peterbilt with a boxed frame.

and refuting another poster's inference that an open channel frame was lighter or weaker than a boxed frame here:

GM uses torsion bar front suspension on the trucks and the chassis is lighter and not boxed like the Ford or Dodge. Every heard people say I really like the GM truck because it rides better than the others? Its simple, its lighter built. It was not up to the task to make a 4500 series or larger so they came out with the Top Kick and Kodiak line.

It is peculiar to me that the a boxed frame is thought to be one that would reduce vibrations. My friend's Ford 6L powered F-350 is noisier and vibrates more than my GMC 3500 Duramax diesel.

Every truck I've ever owned that was heavy duty had a C-channel frame or a C-channel with inverted L doubling like my 4800. Never saw a heavy duty truck with a boxed frame. F-350-550 trucks are toys compared to the heavy trucks, including the ones I've owned & driven and they are mostly boxed.

I guess I'll take the "greater vibration" some claim and the corrosion resistance and big truck build of a C-channel over the light duty truck boxed frame found in a phord.

Different strokes for different folks I guess.

 

[Heywood Jannockitov]

This is merely an uneducated guess on my part, but I think that since light truck frames are typically hydroformed nowadays, that it is easier to produce a boxed channel frame by this method than an open C-channel frame.

The necessary stiffness can be formed into the frame easier and lighter gauge steel an be used to achieve the same rigidity.

Although the manufacturers will tout the "tough boxed frame" as a selling point as travelover pointed out, the real goal is to reduce weight and cost by using less steel in the frame.

 

[capt_met]

i own and work 2 GM medium duty trucks. an old C65 dump that still makes money. also, a 4500 4wd dump truck with the duramax/allison combo. i drove the ford 450 and 550 prior to buying the gm and am very happy with my decision. both trucks work very hard and have been overloaded a time or two. the 4wd system on the 4500 has been flawless. the turning radius on the gm is also tighter than the ford or dodge offering. i also like the 4500 body style, the visibilty is great from it. the turning radius and visibilty make a big diffrence in the areas i often work. the 5:13 gear ratio also is great when towing heavy up mountains. the arguement against the newer medium duty trucks doesn't hold water in my mind. i think GM lost the medium duty market prior to the new trucks. they went a long time living off the older style trucks and didn't try to compete in the 4500-5500 market till it was too late. the late 90's ford super duty and 450 550 were great trucks and during that time it seems ford started really taking over the medium duty market. the sad thing we are all poorer having lost GM's medium duty division. attached is a picture taken on top of Rich Mountain outside Boone N.C.. i was towing a backhoe in 4-6 inches of snow up and around the mountain. there was 3 tons of topsoil in the bed as well. i think they hold their own well.

 

[Travelover]

.................It is peculiar to me that the a boxed frame is thought to be one that would reduce vibrations. My friend's Ford 6L powered F-350 is noisier and vibrates more than my GMC 3500 Duramax diesel.
..............

Boxing the frame helps for things like sensitivity to tire and driveshaft imbalance, idle vibration and road induced shake. It doesn't do much for engine noise - that is primarily airborne.

 

[Cat_Driver]

One of the best combo's was a Ford truck with a Cummins diesel. Only problem is you could only get them in Brazil. The dealer I talked to in Brazil was willing to ship one up to me. I was too scared of serving it obviously.

Bottom line after all these years they haven't made a perfect brand yet. I had great luck with all three and I had some of my worst vehicles with the big three.

Seems it's more the luck of the draw. On the last GM 3500 4x4 I got overheated constantly yet i was told " this is normal " and when I called GM about it they said " gee this is the first we have heard of this" while I know for a fact that many others complained and got buy backs for same issue.

They best display I ever saw was at a Ford dealer they had frame sections from, GM , Dodge and Ford. After looking at the actual pieces of cut frame you would never buy anything but a Ford because of the thickness of teh sidewall on the frame. It was double the Dodge and GM.

I think the demise of the GM 4500 was the size, Ford made a huge hit with their 450 looking like pick up truck while GM had teh look of a huge medium duty truck, just too big.