I have a 1971 240z 4 speed w/ 280z transmission and engine is what i i was told. I was wondering if anyone knew what would cause the shifter to pop out of 3rd gear into neutral ( seems to happen every now and then especially when i hit a bump ). Does this mean i need new bushings ? I don't know much about cars but was hoping for some ideas.

thanks

When the transmission pops out of 3rd gear and into nuetral, are you under power or coasting?

Either way, it is the 3rd gear synchronizer ring that needs to be replaced.

If it jumps out of gear while under power, then you also need to look at the shift fork for 3rd-4th gear. The fork can wear down because of people driving with their hand resting on the gear shift lever. This forces the shift fork to wear prematurely and not allow the the synchronizers to fully engage, thus it pops out of gear unless you forcebly hold it in place.

You need to pull the transmission out of the car and have it rebuilt. You may only need to have the 3rd-4th gear synchro's replaced (depending on how bad the rest of the transmission looks). Manual transmissions are fairly easy to work. Pulling the transmission out yourself will save you some of the labor costs if you have someone else rebuild it.