Q: Experiencing a knocking noise while I'm decreasing speed on the highway. I have examined the up&lower ball joints, tire rods, axle

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Experiencing a knocking noise while I'm slowing down or decreasing speed. I have examined the CV axles, tie rods, upper and lower ball joints and everything seems to be in place. Does not make no squeaking sound like a ball joint would. And no noises when turning left or right. The knocking sound appears to be coming from the driver's side while decreasing speed at stops on straight roads.

My car has 135000 miles.
My car has an automatic transmission.

Hello, thank you for writing in. Inspecting the suspension and steering components was a great idea. Did you perform a visual inspection, or did you actually raise the vehicle and maneuver the parts to check for excess play? However the brakes and the drive shaft can both causing a clunking noise when coming to a stop. Attempt to replicate the noise while backing up. If the brakes are of a concern, you will likely hear it in both directions. Something like your drive shaft may not be heard while backing up. Most of these components can be tested while on the vehicle, but you may need a hand. For more diagnostic help, contact our service department.

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Hi there. Check the brake system and see if the caliper or rotor is damaged on the driver side wheel. Since the noise only occurs when decelerating to a stop, then there could be an issue with the brakes. Try downshifting the transmission on a road with no other cars and let the vehicle decelerate as the transmission slows down the vehicle without touching the brake pedal. If there is no nose, then the brakes is your problem. If the noise is still there, then either there is a loose suspension part or there is a problem with the transmission. Check all the fluids on the vehicle and make sure that they are full and top off any low fluids. If you cannot locate the issue that is making the knocking sound when decelerating, then I recommend seeking out a professional, such as one from Your Mechanic, to help you diagnose the issue.

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