Does anyone know if the 12a and the 13b (SE) use different length driveshafts? I've got a mysterious minor gear oil leak (only after the car has been driven). A mechanic friend of mine thinks that the aftermarket driveshaft in my SE might be a bit too short, allowing gear oil to leak from the yoke while driving when the drivetrain flexs. The driveshaft was on the car when I bought it, so I don't know if it was for a 12a, 13b, or for both.

 

same part number for all the m/t cars 83-85. Mazda kept the transmission in the same place and let the engine go forward. the a/t cars have a longer trans, so they have a different length shaft, by nearly a foot.

 

Maybe the rear oil seal just needs to be replaced. Thats easy to do, just unbolt the drive shaft
at the back, pull it out, drain oil, put in new seal, fill oil, put drive shaft back in. Put the nose up
in the air to get all the oil out or put the rear up to keep most of it in. Your choice.

 

I put in a new rear oil seal when I replaced the clutch a couple months ago.