I have an 86 Wagon with manual transmission. Last night, I started hearing this clunking/knocking sound that seemed to be coming from the lower right wheel. I thought either I had a flat or that the mudflap was hitting the tire.

I made it my destination with just this sound. On the way back home though, stopped at a light, when I went to engage it into 1st gear, a big thump and rattle happened - it felt like something fell out of the front end. I was able to start moving in 2nd gear though it sounded very crunchy....third was a bit better and fourth was smooth.

What could this be? I'm worried it's something major. Clutch? Bearings? Mount? Synchronizer? OR the whole transmission? I need to get it to a mechanic but want to be knowledgeable on these symptoms.

The clutch feels fine. I tried to move it today (in Brooklyn so we have alternate side parking rules) and started off in 1st gear, then tried 2nd - making this knocking sound with each foot it moved forward and the seemed to slip out of gear. Finally, it wouldn't go into any gear and so I rolled it into a space.

Also, when we drove it back the other night, I recall the gear shifter moving itself - like bouncing up and down and left and right.

I just don't want to go to a mechanic with no knowledge and being it is so old, feared it would be something major. A recent problem I had and really the only one since I've owned it is that some bushings failed/came off on the alternator I believe.