I have a 1998 Toyota Corolla with 125k miles. Generally runs great. However, a few years ago I noticed that when I shifted into reverse after starting the car, I’d hear a few quick “clacks” under the car - almost sounded like someone tapping the concrete floor with a billiard ball very quickly two or three times. Then when I shifted into drive, I’d hear it again. I thought it was the transmission, but my garage said they couldn’t hear it though they claimed they found a broken motor mount which they fixed. However, the noise didn’t go away and I decided to live with it. I never heard it when the car was shifting through the gears (from 1 to 2, etc.)
Now it is getting worse and worse (louder), but I’m also noticing that it doesn’t just happen when I shift, but other times when the load on the engine seems to change. For example, I was at a stoplight the other day and my A/C cycled on, and I heard the sound.
Do I just have something loose or could it be the transmission? Any guesses where I should look first? The car otherwise drives fine and the transmission seems otherwise o.k. to me.
Maybe the CV joints on your axles? If it’s getting louder, your garage, or another garage, should be able to find the source.
I second Texases post. This would not be an unheard of sympton for CV joints.
As mentioned above, the CV axles may be the problem. There is a swinger bearing on the passenger side drive shaft on many FWDs and it could be the source of the noise.