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Clanking that stopped when I filled the gas tank

I drove my pickup yesterday and today, about 10 miles each day. It clanked and bounced on every bump and crack, the bouncing lasting for a few seconds. I suspected my suspension. Today I filled the tank (adding 10 gallons to a 17-gallon tank), and the clanking and bouncing were unnoticeable for minor bumps and cranks, only a little for larger ones. I can’t believe that 10 gallons of gasoline made that much difference in the weight. Could it be that the gas tank is loose and causing the clanking? '87 Toyota pickup, long-bed, Xtracab, carbureted, 5-speed manual, 2WD, red with a white Brahma shell, platformate, GL-7, and green power crystals added.

I would suggest the 65 lbs added to the gas tank combined with the trip to the gas station broke the rust bond between the leaves of your rear leaf springs so they could actually flex as designed.

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Or biased them enough so that they don’t go slack when hitting a bump.

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The gas dissolved the green power crystals so they no longer clunk around.

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Secure a bag of cement. That weighs around 90 pounds I think. Then if the clanking starts again, try placing the bag of cement here in various parts of your truck and there to see if the noise goes away again. Might provide a clue. The tailgate on my truck makes a clanking noise when going over bumps, and the severity of the clank is related to how much weight is in the bed. More weight, less clank.

I hadn’t thought about that. I bought more weight in construction supplies (rehabbing the bathroom) the day before.