Propeller Shaft play...How much is TOO MUCH?
 

Hey guys, Its been a while. I had an issue with some rear end noise that could be heard at low speeds. It was intermittent, and I couldn't replicate the sound intentionally. I could only hear it sometimes, typically while making sharp turns in my parking lot. Anyway, I got under the car today and started to jiggle stuff. When I got to the Prop-shaft, I noticed a lot of free play in while trying to spin the shaft. I took a video that ill post here. Im not sure what is typical for an AP1 shaft. But i did recently do a clutch job (~4K miles ago, and everything was fine up until this point). Something that I did not consider, was that my prop shaft could be out of phase, as I had to disconnect the shaft to remove the transmission and the clutch. I didn't take into account that the prop shaft is "phased", and I could have very well have reconnected it back out-of-phase. I noticed some white markings on the shaft, but I cant make out what is supposed to line up with what. Any help at all would be great.

Also, While jiggling stuff I tried to see if the sound was coming from my half shaft axles. Theres a slight amount of play in the axels, but nothing seemed abnormal. Everything was seeming as it was since I did the CV-bucket swap about 2 years ago. One thing I did notice that maybe someone could shed some light on:

While Turning the prop-shaft, with the rear end up, parking brake off and in neutral, I could get both rear wheels to spin along with the prop shaft. I could also spin each wheel individually by hand, without it turning the other wheel. Something that seemed strange was if I put my hand on the Prop-shaft and spun one of the wheels, I could easily keep the shaft from spinning. This seemed almost too easy to do, but I have never tried that before. Could this be a sign of a worn differential? Ive never serviced the diff, other than change the fluid out around 5k Miles ago, and nothing seemed abnormal then. I guess my next maneuver is to drain the diff and check for chunks and the apparent "burnt" smell.

Thanks guys, any advice here would be greatly appreciated.

you need to service the driveshaft. Pull it out. There are two screws that secure the end caps. Lightly tap the cap off and remove as much of the old grease as possible and repack it with new grease.

https://cimg4.ibsrv.net/gimg/www.s2k...06c43845d5.jpg

Glad I stumbled on to this thread. Having similar symptoms with about 230k miles on my original driveshaft. Didnt even know they were serviceable:thumbup:

To note though, the back and forth play isnt in the driveshaft but in the trans/diff backlash in the gears, which is normal to some degree. How much is hard to say. But the vid looks like pretty normal backlash. That's not to say there may not be some vibration coming from the driveshaft that a repack would wouldn't solve. Its what i'm hoping for.

Everything you have explained is normal operation of the dif.

The driveshaft cannot be installed out of phase. The marks are redundant, they are preservation markings.

The prop shaft cv joints can also be replaced, if it ever comes to that. Seen threads covering that, including where to source the joints. Both ends are the same joint.

But it doesn't sound like you have bad prop cv joints.

Whoa awesome I didn't realize they were serviceable! Awesome, thanks for the input here. Im assuming some CV molybdenum grease here would be sufficient? Thank you

Awesome, thanks Billman. I really have never had to think that hard about the diff before. I guess I have to familiarize myself with the inner workings a bit more. As far as the drive shaft phasing, I guess thats only an issue with Universal type joints on the shaft? I guess the constant velocity joints eliminate the need for phasing. This is all new stuff to me so Im just trying to wrap my head around it. Thanks for the input. Im hopnig that the noise I have been hearing is a faulty Wheel bearing on the rear. I have yet to feel any wheel play, but Im still not ruling that out as a culprit.

What would the symptoms of a faulty prop shaft CV joint be on the S? would it be an audible thing? or more of a vibration?