Frame Stiffing to reduce Porpoising?
Got a question for you seasoned drivers with older rigs. I have a 1999 F350 Dually Quad Cab Long Bed. I've been driving it for thousands of miles and for the most part, it's been fine. However, while ...
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I will not weigh in on how good idea it is to stiffen the frame.
Working on heavy trucks, if I suspect excess frame flex,* the first thing I do is look where crossmembers mount. Any sign of movement between the parts? Rust around the fasteners? Then spaces between the members. Any concentrated areas where paint is loose? And are there any places where it looks like the steel has been hot?
Now if you decide you have a frame issue I have had pretty good luck using L shaped piece of frame steel, cut so near as tall as rail, and as wide as the flange. I try to end at crossmembers, and make ends angle, so flange end is longest. Use hard bolts, in holes drilled for tight fit, and flat washers. (NO SPLIT WASHERS!) Drill in pattern so no 2 holes are in the same vertical line, and spaced between half of, and the width of vertical frame section. Most important, NO HOLES IN THE FLANGE
*(Never seen a case on Ford, 500 to 9000, and have extended the wheelbase on more than a few 9000s)
Working on heavy trucks, if I suspect excess frame flex,* the first thing I do is look where crossmembers mount. Any sign of movement between the parts? Rust around the fasteners? Then spaces between the members. Any concentrated areas where paint is loose? And are there any places where it looks like the steel has been hot?
Now if you decide you have a frame issue I have had pretty good luck using L shaped piece of frame steel, cut so near as tall as rail, and as wide as the flange. I try to end at crossmembers, and make ends angle, so flange end is longest. Use hard bolts, in holes drilled for tight fit, and flat washers. (NO SPLIT WASHERS!) Drill in pattern so no 2 holes are in the same vertical line, and spaced between half of, and the width of vertical frame section. Most important, NO HOLES IN THE FLANGE
*(Never seen a case on Ford, 500 to 9000, and have extended the wheelbase on more than a few 9000s)
