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burnin oil · 12-19-2018, 01:22 AM

If it is just the top of the C channel I would just go down to the bone yard and get a chunk of frame of the same thickness. cut out the bad section and weld the patch back in. Dont cut the whole frame, just the bad part of the C channel. Be sure to round the corners so that there are no 90 degree cuts. This should be plenty strong. Everyone will have an opinion on fish plating but I would not do that for a repair as I described. The rail should be plenty strong and still flex. The fish plating arguement could come up but think about this. If you only plate one side then the opposite rail cant flex the same and will also cause a stress area. Frames are welded every day without fish plates and this is one of those occasions that I would not. Guys will weld the whole frame front to rear, cut reliefs, and add brackets. Its only when the frame is cut into two pieces is when the plate issue even comes up. Heck most modern small truck frames are 2 pieces slid together then plug welded and stiched at the joining point. Holds up to a 1 ton diesel just fine.

Now if the above repair encompasses a spring hanger area then I would stick a plate on the inside of the frame to add a little security. I also abuse my trucks harder than the average guy. Extra power and used as a truck, not a cruiser is my style.

12-19-2018, 01:22 AM	#5
burnin oil Registered User Join Date: Jan 2013 Location: Eastern TN Posts: 1,921	Re: Frame repair If it is just the top of the C channel I would just go down to the bone yard and get a chunk of frame of the same thickness. cut out the bad section and weld the patch back in. Dont cut the whole frame, just the bad part of the C channel. Be sure to round the corners so that there are no 90 degree cuts. This should be plenty strong. Everyone will have an opinion on fish plating but I would not do that for a repair as I described. The rail should be plenty strong and still flex. The fish plating arguement could come up but think about this. If you only plate one side then the opposite rail cant flex the same and will also cause a stress area. Frames are welded every day without fish plates and this is one of those occasions that I would not. Guys will weld the whole frame front to rear, cut reliefs, and add brackets. Its only when the frame is cut into two pieces is when the plate issue even comes up. Heck most modern small truck frames are 2 pieces slid together then plug welded and stiched at the joining point. Holds up to a 1 ton diesel just fine. Now if the above repair encompasses a spring hanger area then I would stick a plate on the inside of the frame to add a little security. I also abuse my trucks harder than the average guy. Extra power and used as a truck, not a cruiser is my style.