Shaking Truck Causes Concern

Q. I have a 1995 F-150, Ext Cab that seems to develop stranger problems as it gets older. The current one is that it has developed a shimmy at 40-45mph, but only sometimes. Sometimes, it's so bad I can't even see a good reflection in my side mount mirror. It does smooth out as I go faster, or just becomes less noticeable. I had the three CV joints replaced and the tires balanced and rotated, but this made no change. My mechanic says maybe I should live with it until it starts happening all the time. I think it started happening when one of my leaf springs broke, just out of the clamp. I pulled out the broken part, and the remainder is still intact, nothing loose. Do you think there could be a connection with the missing leaf spring half and the shimmy?
A. It's not too likely that one broken leaf spring is causing the shimmy. However, you might want to consider getting a different mechanic. It's never a good advice to keep driving your truck with a problem that is uncomfortable or potentially unsafe. There are a number of possibilities. It could be due to loose or worn suspension or steering components, problems such as U-Joints, or tires. You should also have the idler arm, center link, and tie rods checked out. If the wheel balance was done and checked out okay, then check the steering component listed.