Well I've had this problem ongoing for awhile now and its recently gotten much worse. Basicly, with both wheels on the ground I can hand turn the driveshaft over half a turn in each direction before it locks. During driving this causes a smack that can be felt all along the drivetrain when on and off the throttle. Parts that have been replaced so far are a new center bearing, helical differential, and a new SR tranny. Yet with these the problem is still prevelant and is getter worse as time goes on. I am wondering if anyone has had this problem and what course of action did they use to repair and trobbleshoot the problem.

 

if you can get ahold of a spare driveshaft, try it out, i've heard driveshafts themselves can be out of balance. it's rare, but my neighbor had this problem on an otherwise stock s14.

 

All those new parts and there's still half a turn of play in the DS? I'm not even close to an expert but that doesn't sound like a DS balance problem... you think that could be?

 

The driveshaft seems to operate fine after the "smack" from the throttle on. No vibrations or anything. I don't think an unbalanced driveshaft would cause play in the shaft itself, wouldn't it just vibrate at certain speeds or RPMs?. I could be wrong.

 

carrier bearing replaced??? had the same problem and it was my carrier bearing. how about your differetial? is it good

 

well the drive shaft is 2 pieces did you pull it apart for inspection?

 

Are you in gear when it finally locks? the diff should stop the DS from turning no matter what? The smack you are feeling, where is it comming from exactly. The back or the front of the car will have a great amount to do with the problem.

 

The smack is felt all through the driveline when it locks. The origin feels like its coming from the rear. When i take my hand and turn the shaft abruptly, obviously when the freeplay locks its going to be felt at both ends of the driveline (tranny and diff), since they are connected via the driveshaft. The differential is a new helical and works perfectly despite this problem. The play in the driveshaft is definatley causing the problem, but I'm having a hard time figuring out the origin of the play.

Regards to JimmyHat's post, it doesn't matter whether the car is in gear or not, with both wheels planted and not moving there should not be play in the driveshaft, but yes the smack is felt when shifting gears because when the power between the shift disengages, the driveshaft clunks or smacks to rid the slack, and then when on the throttle, it smacks again, relieving the slack or play. I can toggle this on and off the throttle in any gear and it's getting so bad that I'm afraid the driveshock from this "smacking" is going to break something.

 

if it does it when the car is off and in gear then its your transmission side most likely. if it does it in neutral its the diff side. also what anthony said could be true.

 

Than I sau tits the U Joints on the DS. Swap it out and see it it fix's it.