Ok so I need some help here. I have been using my recently dealer purchased 2000 f 450 dump for a couple of Weeks now. I noticed that the bed looks like it sags down toward the cab and is higher in the back.most of that is the bed being bent up I have deciphered.
But also I noticed that the frame and cab don't seem like they are on an exact 90 degree angle to each other. I looked at the frame, the part right behind the cab (like an inch so behind it.) The top rail is bent up a little right before the point where the frames angles down to go under cab. It is the exact spot where the crossmember rivets on the top rail.
It is basically identical on both sides of frame.(almost looks like that is just how they were made.)
Can somebody please tell me if that is normal or not. And if not what should I do. I want a strong reliable truck for work (landscaping) please help

 

Can you post a picture of what it looks like? Also do you know of any accidents that the truck may hsbe been envolved in? Another thing, depending on your location You could have the cab support rotting out or a worn body mount

 

I think it is in your best interest to figure this out ASAP. In some states, if not all, it is illegal for a dealler to sell a vehicle as having a clean title and/or passing safety inspection with a bent frame.

 

your best bet would to go to a repair shop that specializes in frame repair and have them put the truck on their rack and inspect it to see if the frame is bent or not. the computer on the frame machine will tell you instantly if there is a problem or not.

 

You are assuming that the cab and frame should be at right angles, which may not be true. Also, a bent or damaged cab mounting point could cause a misalignment also, so as already recommended have the truck checked at a frame shop.

 

Ya redford I was thinking the same thing. Thats why I asked on here maybe someone has the same truck. I think having it checked before confronting dealer is a good idea.

 

Does anybody have the same truck/frame to give me some insight on this? It is like a luttle raised area of the top channel of frame right before the angle down to go under cab.
The truck is rust free completely! This is only a worry with the frame. No way it is body related. My only concern is frame.

 

I was looking into Buying a 99 F450 with a flatbed on it and I did not notice any abnormal bends in the frame. Like others said get that looked at ASAP

 

Yes, I do.

But without a picture of the area of your frame, there is nothing I can help you with.

It is common for overloaded dump trucks to have bent, cracked, and more rarely sheared frames in the exact area that you are talking about.

But to be able to compare your suspect frame to my correct and in tact frame, I'd need to see a picture.

 

i could not figure out how to post pics. it wont let me attach them since i am not a paid member. i took some pics and uploaded them to my photo album in my public profile. you can go there and see them. some of them are upside down or sideways however, but you can get a pretty good idea how the top channel buckles down a little, then up, and then down a little right before it angles downward to go under the cab. please let me know what you think. after seeing the pics as close up as they are i am more convinced that that is not normal. i am going to take take truck back to dealer tommorow or tuesday and show them. thanks for any and all help.

 

easiest way to do pictures is post them to photobucket, then copy and paste the link here.

that frame is messed up.

 

thanks. i am going to request that dealer straighten it and reinforce it in that area.

 

Anyone else have any opinions/ advice. It is not bent that bad at all but I am concerned about future and it being weakened.

 

I tried to look at the pics in your profile.

I could only see the thumbnails. When I clicked on a thumbnail, a window with arrows appeared, but the image never loaded. I wanted to click on enlarge after that, so I could really see, but could never get an individual image to stage first, for that to happen.

I went back to your profile, and turned my entire computer upside down so I could decipher your thumbnails, since you posted some of your pictures upside down, and the thumbs images were too small to get oriented. Plus, not knowing which pics were upside down and which werent made it more difficult.

The one orienting factor I did find was your roadside frame rail, due to the fuel lines and plastic bracket which I recognized.

With that picture, and those similar, I determined that you are observing a warp in the top flange of your frame rail spanning about two inches. Did I read your thumbnail correctly?

If so, the warped upper flange's horizontal deviation from dead flat is not much greater than one half the plate thickness of the frame... did I see that correctly?

If so, then that is common with rigid second unit body mounts in the cab area, and is not warranting of straightening, as straightening will not restore any strength to that area, and stiffening with reinforcements will, unless properly engineered (more on that later) cause a different area of the frame to absorb the frame twist that comes from the front axle and the rear axle being on different planes (turning from a crowned road into a side walk driveway angle, for example).

The proper way to mount a second unit body (hereinafter referred to as SUB) is well documented in the Ford Body Builder's Advisory Service handbooks. These guides are available online, and are easy to look up if you want to wave some diagrams in your selling dealer's face.

Long story short, a fully rigid SUB to chassis frame mount, with shear plates bolted through the web of the frame, not just the flange, is best done aft of axle, aft of the rearmost spring hanger, in the area where there are four open holes in the frame web just aft of the aft axle fuel tank cross member. That's basically where the hinge point is of your dump bed. Your dump bed sub frame should be rigidly mounted there.

But up front, by the cab, the type of mounting should have a "fuse".

There are several different ways a fuse can be fashioned. On ubolt mounted SUBs, such as box trucks, two pieces of oak are used between the chassis frame and the SUB sub frame. But dump bodies are not usually ubolted.

Ford recommends, strongly, the use of shear plates upfront, bolted to the web at a 45 degree angle. Some of the more sophisticated implementations of SUB mounting have that shear plate be an inverted L, with the short leg of the L becoming an outboard flange which becomes a platform for a spring bolt arrangement.

The springbolts keep the SUB secure on the frame, and the tension of each spring (about the size of valve springs) works in opposition against the upper and lower surface of the add on outboard flange, maintaining secure contact as well as fastener tension. The bolt itself is sized thick enough for shear.

However, in extreme twist ditch manuevers, where the front axle is on a radically different plane than the rear axle, which causes the frame to helix, the spring bolt fastener assemblies absorb some of that twist that would otherwise be absorbed by your frame flanges.

The frame flanges are that part of the frame were both tension and compression are greatest, because they are furthest away from the neutral axis of the frame, which is in the center of the web. This is why there are those big red and white labels on the back of the cab of the F-450 that yell DO NOT DRILL INTO THE FRAME FLANGES.

It's because the flanges are doing all the work of that frame. And, as evidenced by the best that I could decipher from your thumbnails, they have been doing some work on your F-450.

My suspicion is that your SUB was not mounted in as sophisticated of a manner as the best engineered SUB mounts. My suspicion is that your dump body is rigidly mounted at the front as well as at the rear, perhaps even with shear plates that are welded to the web of the chassis frame as well as SUB sub frame. And that is fine aft of axle.

But at the cab area, you can expect to see some warpage as the steel in the flange is stressed beyond it's ability to restore it's original shape.

There is also the possibility that the dump body was overloaded from time to time. Easy to do with wet dirt and dense 1/4 by dust gravel.

Ford makes an F-550 chassis with a high GVWR package, and of interest is the frame rail enhancement to that package. I bring this up due to your talk of wanting to reinforce your F-450 frame. Before you do that, I would recommend that you take a look at how Ford reinforced their frame, which is dimensionally the same as yours, but which gets a 70% increase in section modulus as a result of their frame reinforcements.

When you look at the reinforcement, there is a diagonal separation in the critical area where your frame flange warp is... the cab to SUB junction that is about the midway point between contact patches of the two axles. This is the area of the frame that is PERMITTED to absorb the frame twist.

You don't want all the frame twist to occur under the cab, cause the cab will get tweaked beyond the allowance of the cab mounts, and because the frame is still natrually more rigid in that area due to the additional crossmember of supporting the transmission.

Just the same, you don't want the frame twist to happen under your SUB, because the structure of the SUB disallows it... and the frame is naturally more rigid due to the major crossmember that ties together the two forward mounted rear spring hangars.

So Ford's frame reinforcement has a clever separation between channels at the CAB to SUB junctional area, that controls how the reinforced frame deals with twisting stresses. The frame will move, because the earth will not. The suspension cannot soak up all the all of the planar differnences the two axles encounter.

I'd say the flange deviations that I can interpret from your pictures are not critical, but I can agree with you and see how they would be concerning. I would be carefull how you reinforce Fords frame, if you feel the need to do so.

I would be more inclined to not overload the F-450, first and foremost, and then I would look at how the dump body sub frame was mounted in the forward anchoring position of your truck, and compare that mounting with some research on manufacturer recommended bed mounting practices for all types of trucks, not just Fords. Much can be learned from the reading their recommendations. I have found that the best practices resonate with commonality.

Good luck.

 

WOW!! That was much much more of a response than i ever expected!! probally the most elaborate response in the history of this website!! if not of all the forums on the net. great info on aftermarket installations. Thanks!

i took it to the dealer today and they say they dont see anything wrong. they say that if the top channel bent like that and if the whole frame was bent down that the side and bottom channel would be distorted also, which they are not (or at least not plainly visible to me). that seems to make sense. i thought of that before also, but to me just looking at the truck the cab and chassis dont seem to be at an exact 90 degree angle, as is the case with every other cab/chassis from any other manufacture including ford that i have ever seen.

there is a heavy duty truck frame shop about 30 minutes from me they do everything from lenghthening frames to leaf springs, drive shafts, custom welding, the whole 9.
i am going to try to convince the dealer to have the truck sent to them and pay for the frame being checked and if bent fixed.
if they wont i am going to take it there myself.

i currently have and have had a 1989 chevy 3500 dump that i purchased in 2005 when i started my landscaping business. the truck has been great, always reliable and has made me a ton of money, but being an 1989 it is just getting real tired. (it has been through 2 motors, head gaskets twice, 4 clutches etc.....)

that is why i brought this ford. it is in really great condition rust wise and everything works like new and it only has 60k miles on it. i figure from what i have read that with the 7.3 diesel it has it can be great dependable truck for many years to come. thats why i got so scared seeing the frame like that.

i feel a little better after your post and also knowing that there is a frame shop close by, so no matter what i will end up with a strong properly aligned frame and have a good work truck. it is nice its a class 4 a nice step up from the 3500 also.

i really appreciate your taking the time to look at my pics and respond like that. thanks Ben