I bought a beautiful 88 745TI with a M46 trans very recently. The car has 114K miles on it. This is the first vehicle I've owned with a manual trans (very excited) and first volvo. After doing several shifts from 1-2-3 and back through the gearbox around town, it becomes increasingly harder to put the car into 1st and sometimes impossible. Yesterday, it completely locked me out of all of the gears. When I allow the car to sit in neutral after being locked out for several minutes, it shifts fine for the next 5min and I then have the problem again. On one occasion, during these troubles, I took my foot off of the clutch pedal and the pedal did not return all of the way. I put my foot behind the pedal to bring it back up and did not have this problem again (i was around the corner from my house).

I read the notes in the FAQ about changing the trans fluid and adjusting the clutch cable. However since this is the first vehicle I've owned with a standard trans, I really have no experience with the mechanics of this. I also have yet to look at the cable or trans.

My questions are:
1. How do I know if the cable needs to be replaced? Will it break all of a sudden?
2. What kind of fluid should i replace the transmission fluid with? Do I have to do a flush to switch to a synthetic?
3. Could this be another problem other than fluid or cable?

thanks,
-jeremy
Philadelphia