Rear frame rot
- Thread starter Baker7888
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Don't know if this would work but what about using the plates for a frame notch kit? Normally they are used on the outboard side but maybe could be used inside? I repaired my El Camino many years back just with steel plates but it had the Frankenstein look due to the many welds.
Just a suggestion.
Just a suggestion.
Better check the rest of the frame out for rot. Likely there is rot other places too.
Ironically everything else is good. The car is in better shape than my 04 sierra. It had a massive amount of under coating, then up front a rear main seal leak from the original v6 kept everything fresh
I too have the rear frame rails rotting as my Malibu did come from Washington. The whole rest of the frame is fine. It's just that rear section behind the axles where it straightens out. It's on an up coming project. Right now it's considered "The Rear Crumple Zone". It'll be on next years project since the car now resides in AZ. You've heard the term "I know a guy who know some people who knows a guy". I know the guy! He's just gonna cut out the rot and weld in new plate.
So the section of rear frame horn that you need has to include at least the first part of the kickup that takes the frame rail over the rear end.?
Couple of more questions here.
Beyond what is visible in the pictures, how far up the side of the existing frame horn does the cancer go? I am seeing an oblong hole in the frame wall in the one picture; does the rot quit before it gets to that hole?
Where I am going with this is that, while it would be nice to plug in a complete section of rail, if you can cut away the rot to clean metal and still have about half the side wall of the old rail showing, then it is possible to fab up a replacement section of material from flat plate and graft it in as a repair. All the pictures show me is that it is the side wall that is nasty; is the bottom section where the two halves overlap still intact? That whole area appears to be wide open as if the rear end has been dropped out and set aside to gain working room. To me that makes it possible to do a panel repair instead of a total cut away and insertion. What makes going with the panel something to consider is that it eliminates the need to fish plate the seams once you have the new horn installed. While it looks like the connections could be a case of just using butt welds, edge to edge, That section of frame is a structural member and has to support the body section that sits on it which in turn has to support the gas tank. Gas weighs, approx, 6 lbs/gal so a twenty gallon tank, full, weighs around 120 pounds plus the weight of the tank itself, plus the weight of the rear bumper and associated components for it. All this is just static load, weight just sitting there. When you are driving down the road and your suspension is articulating, the frame is being subjected to stress from the vertical action of the suspension as it moves up and down. The butt welded seam might hold but the frame horn might also tear away just beside it.
I honestly wish i had been able to take pictures of the frame horn section replacement that I did for my Monte to show you exactly how much re-inforcement of the joint needs to happen. The are shots on this board of the frame cleaning work that I just completed prior to rehanging the rear end and they clearly show the diamond shaped fish plate that lies squarely across the welded seam. it is both rose or plug welded to the side wall and then burned in completely using a perimeter weld around the edges. it doesn't look all that pretty but it was never intended to win a beauty contest. What you can't see is the pair of plates that i sistered to the inside face of the existing rail and the new horn using plug welds to secure them, one on each side wall. With them in place i could not only weld the two edges to each other but also to the inner plate by leaving a slightly wider gap to help with the penetration. By comparison it would almost have been easier to do a frame off and toss the old frame away in favor of something in better shape; thing being that cherry, un molested, pristine, rust free frames are like hens teeth up here in the land of the Frozen Chosen.
Nick
Couple of more questions here.
Beyond what is visible in the pictures, how far up the side of the existing frame horn does the cancer go? I am seeing an oblong hole in the frame wall in the one picture; does the rot quit before it gets to that hole?
Where I am going with this is that, while it would be nice to plug in a complete section of rail, if you can cut away the rot to clean metal and still have about half the side wall of the old rail showing, then it is possible to fab up a replacement section of material from flat plate and graft it in as a repair. All the pictures show me is that it is the side wall that is nasty; is the bottom section where the two halves overlap still intact? That whole area appears to be wide open as if the rear end has been dropped out and set aside to gain working room. To me that makes it possible to do a panel repair instead of a total cut away and insertion. What makes going with the panel something to consider is that it eliminates the need to fish plate the seams once you have the new horn installed. While it looks like the connections could be a case of just using butt welds, edge to edge, That section of frame is a structural member and has to support the body section that sits on it which in turn has to support the gas tank. Gas weighs, approx, 6 lbs/gal so a twenty gallon tank, full, weighs around 120 pounds plus the weight of the tank itself, plus the weight of the rear bumper and associated components for it. All this is just static load, weight just sitting there. When you are driving down the road and your suspension is articulating, the frame is being subjected to stress from the vertical action of the suspension as it moves up and down. The butt welded seam might hold but the frame horn might also tear away just beside it.
I honestly wish i had been able to take pictures of the frame horn section replacement that I did for my Monte to show you exactly how much re-inforcement of the joint needs to happen. The are shots on this board of the frame cleaning work that I just completed prior to rehanging the rear end and they clearly show the diamond shaped fish plate that lies squarely across the welded seam. it is both rose or plug welded to the side wall and then burned in completely using a perimeter weld around the edges. it doesn't look all that pretty but it was never intended to win a beauty contest. What you can't see is the pair of plates that i sistered to the inside face of the existing rail and the new horn using plug welds to secure them, one on each side wall. With them in place i could not only weld the two edges to each other but also to the inner plate by leaving a slightly wider gap to help with the penetration. By comparison it would almost have been easier to do a frame off and toss the old frame away in favor of something in better shape; thing being that cherry, un molested, pristine, rust free frames are like hens teeth up here in the land of the Frozen Chosen.
Nick
Just a curious question... Are rear sub frames commercially available? I know on my 81 Firebird spring hangers bad, and rear over axle rails rotten, common problem with F-Body. The rear subframe kit was $2,500 (2008), now I guess they are running about $4,000. Is similar available for the G Body?
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