jeffl1107 Posted October 23, 2010 Share Posted October 23, 2010 Hey Guys,Need some input on this. About 3 weeks ago I started noticing when I was coming to a stop and I was heavier than normal on brakes the truck would sometime start to jump up and down. Would have to let off the brakes to get it to calm back down. Then about a week ago I noticed that the front end was sagging on the passenger side. Then today I noticed when I got loaded (its a tri axle dump) that the front end was really sagging on the passenger side. I looked underneath. On drivers side the cushion (not sure what it is called) that is on the shock bracket ontop of leaf springs, the travel between frame and cushion was around 4 inches. On the passenger side it was practically touching the cushion. I did not see any visible cracks or breaks on the leafs, but wouldnt you say that the leaf spring has to be the culprit here? Quote Link to comment https://www.bigmacktrucks.com/topic/16247-front-end-sag/ Share on other sites More sharing options...
MACKS Posted October 23, 2010 Share Posted October 23, 2010 Broken springs,shackles,or pins,you need to get to a spring shop. Quote Link to comment https://www.bigmacktrucks.com/topic/16247-front-end-sag/#findComment-65718 Share on other sites More sharing options...
Rob Posted October 23, 2010 Share Posted October 23, 2010 Hey Guys,Need some input on this. About 3 weeks ago I started noticing when I was coming to a stop and I was heavier than normal on brakes the truck would sometime start to jump up and down. Would have to let off the brakes to get it to calm back down. Then about a week ago I noticed that the front end was sagging on the passenger side. Then today I noticed when I got loaded (its a tri axle dump) that the front end was really sagging on the passenger side. I looked underneath. On drivers side the cushion (not sure what it is called) that is on the shock bracket ontop of leaf springs, the travel between frame and cushion was around 4 inches. On the passenger side it was practically touching the cushion. I did not see any visible cracks or breaks on the leafs, but wouldnt you say that the leaf spring has to be the culprit here?That rubber bumper is called a "jounce bumper" and does not allow the leaf spring to "arch over" from a positive, to negative arch. You definately need to visit a spring shop soon as mentioned.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/16247-front-end-sag/#findComment-65722 Share on other sites More sharing options...
jeffl1107 Posted October 23, 2010 Author Share Posted October 23, 2010 Ok thats what I thought. Thanks for the info Quote Link to comment https://www.bigmacktrucks.com/topic/16247-front-end-sag/#findComment-65725 Share on other sites More sharing options...
jeffl1107 Posted October 27, 2010 Author Share Posted October 27, 2010 Ok need more help. I replaced the front spring on passenger side. Although it helped the travel between bounce bumper and frame, I still obviously have a problem still. I just cannot figure this one out. The travel between the frame and bounce bumpers on the rears seem to be ok. Body seems to be ok in the down position on the frame. I cant figure out what is causing this problem. Starting to get nervous that something might be structurally wrong. Any suggestions? Cant say the ground was perfectly level in the picture, but pretty level and it was while I was loaded, probably 25 ton. Quote Link to comment https://www.bigmacktrucks.com/topic/16247-front-end-sag/#findComment-65886 Share on other sites More sharing options...
jeffl1107 Posted October 27, 2010 Author Share Posted October 27, 2010 Here is a picture just after I dumped. Quote Link to comment https://www.bigmacktrucks.com/topic/16247-front-end-sag/#findComment-65887 Share on other sites More sharing options...
Mike Posted October 28, 2010 Share Posted October 28, 2010 Jeff, I'm by far no expert but, I would measure some places on the truck. On a garage floor or where it is close to being flat, I would measure the frame in front on both sides to see if it has been bent in some time. If it is close to the same measurement then it's possible the body may be sagging on one side than the other. That is my thinking but, again you need Dr. Rob, Dr. Moe, Dr. Larry. Lets hear back from you soon. mike Quote Link to comment https://www.bigmacktrucks.com/topic/16247-front-end-sag/#findComment-65905 Share on other sites More sharing options...
Rob Posted October 28, 2010 Share Posted October 28, 2010 Here is a picture just after I dumped.Did you replace only the spring and not the pins, bushings, cushions, shackles, etc? These parts all work and wear together. With a lean as pronounced as the photos show a sag in the frame would be discernable to the naked eye. Sighting the cab also has a lean to the right I would look for a stressed frame. If it is cracked or broken, it must be repaired/replaced or you're headed for expensive trouble. Be certain to look where the crossmembers are attached to the frame for fatigue. Broken crossmembers are a vital clue to look for.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/16247-front-end-sag/#findComment-65908 Share on other sites More sharing options...
oldmacktrucks Posted October 28, 2010 Share Posted October 28, 2010 Looks to me like a stressed frame, check behind the cab...was that truck always a dump, or did someone convert a tractor...if the frame was stretched it could be weak thus giving you the sag. Quote Link to comment https://www.bigmacktrucks.com/topic/16247-front-end-sag/#findComment-65917 Share on other sites More sharing options...
jeffl1107 Posted October 28, 2010 Author Share Posted October 28, 2010 Yes, everything was replaced on the spring. I purposely held back some info to see what you guys came up with. Now I am afraid of what might be going on. Before I purchased the truck, the frame was cracked about 2 foot behind the cab on drivers side. About right in the middle of where the lift axle bolts up to the frame. I never caught it before I bought it and the guy held back a few things about the truck that he should have told me about. The other things were mechanical things I took care of. But this was something that threw me for a loop when I found it. I had a guy weld the frame (and he told me about having to weld in small increments and let it cool down very slowly), there is a piece of metal same shape as the frame, only 1 size smaller that was put inside the frame on the inside as a fish plate that spans 1 foot in front of crack and about 2 foot behind. It has several bolts going threw it. And a piece of angle iron that was welded on top spanning about the same area as fish plate. Now, visibly, I dont see anything wrong with it. I dont see it cracking again, it does not seem to be sagging there. But maybe you know better than me. If I am looking at the front of the truck head on like in the picture, does it not look like the passenger side is lower than the drivers side. The crack is on the drivers side. I would think if that crack was giving way, and like I said, I see no signs of that, that the truck should be sagging the other way. I would think that the weight of the truck being loaded would put stress on the crack and push it down, which the crack is almost dead in the middle of truck. Whats your take on it??? Below is a picture of it BEFORE it was welded by my guy. This is how I found it. The top was welded and ground down, probably to hide it. But the inside frame was not welded. To tell you the truth when myself and the guy who welded it looked at it, and maybe you can tell from pic, it looks like someone blew threw it with a torch. Quote Link to comment https://www.bigmacktrucks.com/topic/16247-front-end-sag/#findComment-65918 Share on other sites More sharing options...
rhasler Posted October 28, 2010 Share Posted October 28, 2010 Yes, everything was replaced on the spring. I purposely held back some info to see what you guys came up with. Now I am afraid of what might be going on. Before I purchased the truck, the frame was cracked about 2 foot behind the cab on drivers side. About right in the middle of where the lift axle bolts up to the frame. I never caught it before I bought it and the guy held back a few things about the truck that he should have told me about. The other things were mechanical things I took care of. But this was something that threw me for a loop when I found it. I had a guy weld the frame (and he told me about having to weld in small increments and let it cool down very slowly), there is a piece of metal same shape as the frame, only 1 size smaller that was put inside the frame on the inside as a fish plate that spans 1 foot in front of crack and about 2 foot behind. It has several bolts going threw it. And a piece of angle iron that was welded on top spanning about the same area as fish plate. Now, visibly, I dont see anything wrong with it. I dont see it cracking again, it does not seem to be sagging there. But maybe you know better than me. If I am looking at the front of the truck head on like in the picture, does it not look like the passenger side is lower than the drivers side. The crack is on the drivers side. I would think if that crack was giving way, and like I said, I see no signs of that, that the truck should be sagging the other way. I would think that the weight of the truck being loaded would put stress on the crack and push it down, which the crack is almost dead in the middle of truck. Whats your take on it??? Below is a picture of it BEFORE it was welded by my guy. This is how I found it. The top was welded and ground down, probably to hide it. But the inside frame was not welded. To tell you the truth when myself and the guy who welded it looked at it, and maybe you can tell from pic, it looks like someone blew threw it with a torch.On a few rare occaisions I have seen RD with double frame rails break about midpoint of the cab (both sides), but the truck had been badly abused. You might have broken bolts at the right rear motor mount bracket where it mounts to the frame rail. If I remember correctly the rear spring hangers, cab mount, and motor mount brackets share mounting bolts. As Mike said before, comparing measurements on both sides may help you find the problem. Quote "Mebbe I'm too ugly and stupid to give up!" Link to comment https://www.bigmacktrucks.com/topic/16247-front-end-sag/#findComment-65921 Share on other sites More sharing options...
Rob Posted October 28, 2010 Share Posted October 28, 2010 I purposely held back some info to see what you guys came up with. Sorry, but I can't work with this.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/16247-front-end-sag/#findComment-65933 Share on other sites More sharing options...
Mike Posted October 28, 2010 Share Posted October 28, 2010 Sorry, but I can't work with this.Rob Yes Rob I understand. I feel the same way. Nobody needs to hold out information when they are seeking help from people wracking their brains to help. I would suggest a Frame Shop from this point forward. mike Quote Link to comment https://www.bigmacktrucks.com/topic/16247-front-end-sag/#findComment-65937 Share on other sites More sharing options...
fifth wheel Posted October 28, 2010 Share Posted October 28, 2010 He needs to put his new toy away and play with his skateboard, he has a bigger problem than a broken frame. Good luckFW Quote Link to comment https://www.bigmacktrucks.com/topic/16247-front-end-sag/#findComment-65944 Share on other sites More sharing options...
oldmacktrucks Posted October 29, 2010 Share Posted October 29, 2010 I agree with Rob, why ask and hold back info? Makes no sense. My personal opinion would be to take it off the road, export it to Nigeria and buy a one ton mason dump to play with. Good day and good luck. Quote Link to comment https://www.bigmacktrucks.com/topic/16247-front-end-sag/#findComment-65992 Share on other sites More sharing options...
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