Hi Guys,
I am wondering if I need a new drive shaft or not. I have an 04 cayenne s with 75k miles that I suspect the drive shaft is bad. The symptoms I get is when making a turn it feels like the front wheels are shifting direction little bit, also I get a knocking noise in the mean time. I had a technician check the axles which were good. The drive shaft on the vehicle was replace at 35k and an inside source info of they last about 35k for these vehicles which is about right for this case. I have also inspected the drive shaft and the center support mount. The mount is in place and not torn, however there is a little bit movement in the area. Since the last time I replace the shaft the same amount of movement was present and I was getting similar symptoms expect feeling like a flat tire. After I replaced it at the dealer it took care of it. My question is if anyone else is experienced this issue and if that is really the problem, should the drive shaft be rock solid with no movement at all. Also on the uneven roads sometimes I get a kind of something shaking or rattling underneath the car, which also feels like a bad center support mount for the drive shaft. The funny thing is when I take it to a test drive with a technician everything seems to be perfect. I would really appreciate any input thanks everyone for your help.

 

Mine went around 60k and you know when it goes. It bangs pretty hard if you get on the gas.

 

Mine works fine when moderate accelerating. Just when cornering it bangs really hard, and rattles when driving on uneven road. I Should try hitting the gas, will I get banging? Will try this soon? If I do then I know it is the drive shaft for sure.

 

If you hear what sounds like a rock tumbler from your center console area while accelerating - likely you've got a shot drive shaft.

Hard to diagnose the issue over the internet - but definitely sounds like a candidate.

 

Thank you house motor. The noise occurs when turning. While the steering is straight it doesn't clunk. It appears to be coming from under the dash towards the hood area. I had the drive shaft inspected, the center support mount is starting to go bad. It has little cracks on it but still in place. When having a shot drive shaft as you mentioned does that mean the center mount is bad. The center mount can be replaced alone from (vertex auto) supposed to be a permanent fix for the bad drive shafts. Unless that is not the case and I need a complete drive shaft. The one thats on there now is factory drive shaft installed by the dealer.

 

We've used a customer supplied EPS drive shaft center mount replacement in the past - and it seems to work as intended. The actual drive shaft itself is never damaged, it's always the support bearing that fails, causing the actual drive shaft to rattle around and smack the undercarriage of the vehicle upon rotation. Per Porsche - this bearing is a non serviceable part and requires the full driveshaft to be replaced.

Unfortunately Porsche hasn't made any changes to the factory driveshaft for that model - so it will have the same tendency to fail over time just like the unit that it is replacing. The center mount/bushing from aftermarket companies is worth trying I would say in your situation!

 

Thank you House Motor. I appreciate the time you are putting to explain the details. I would be going on my 3rd rive shaft in just 75k miles, which I think is horrible. It would make seance that when the center mount is broken and while accelerating the drive shaft would rattle and hit the undercarriage of the car. However in my situation the mount is in place (not broken). It has little cracks according to the tech, and it moves up and down little bit when moved by hand which is normal I world suppose because it is a mount made of rubber, so little play is normal. Also when I accelerate while driving straight it makes no noise at all. Doesn't matter if I hit it hard or moderate. It only clunks when I turn the steering (when turning from one street to another) it clunks once and continuously same clunking sound as I turn, (more repeats if I drive fast and less if I drive slow. It goes away when the steering comes to straight position. At this point I am suspecting that it might be a power steering issue. As for the bearing support, do you mean the mount is failing (going bad) or the actual bearing itself? The EPA support is only replacing the center mount and doesn't touch the bearing. So if it is the bearing that is failing which causes the
mount to go bad, when I replace the EPA support I really did not fix the issue. Except bought more time for it to make the new support to go bad. If it is the bearing, then It would be more reasonable to buy the aftermarket mount which comes with a new bearing where the EPA is the support only. Not sure how to approach this issue as they are all costly repairs and I am little confused from where to start. In my opinion if it is the center mount that is going bad, the $399 support from EPA which comes with 5 year warranty plus $100 or so labor would be much cheaper then the $1400 drive shaft. Thats if I don't need to touch the bearing. Thanks again House Motor I appreciate your help, as Im trying to understand what is really happening to the car without paying for unnecessary expensive repairs. Also, if I choose to go with the aftermarket center mount which comes with the bearing, then I would think the drive shaft needs to be removed and taken apart for the new bearing to be instal. Then does it need to be balanced? How many hours labor would that be?

 

When the cardan shaft fails, it is usually the bearing that is the point of fail.
When this happens, the job of the bearing is not being done. Its job is to keep the two parts of the shaft in alignment with each other.
So when the bearing fails, the two rotating parts of the shaft are no longer concentric when spinning. This creates a wobble at the bearing location, that produces the rock tumbler effect where noises seem to be coming from the underside of the vehicle.
You noticed that you were able to move the shaft up/down and left/right at the bearing location. That is the issue. - Since you mentioned that the clunking noise gets more frequent if you are driving faster during a turn, and less frequent as you drive slower - the noise is coming from a rotating part (driveshaft) that is matching your speed/rotations on the cardan shaft itself.

The fail progression differs in each case. Greatly depends on how you drive the car too. If you are always gentle and drive slowly, it may take a long time. If you accelerate harder, it will likely get worse quickly. The wobble causes further damage to bearing under acceleration, causing more wobble, causing more damage, etc, etc. When wobble gets bad enough, the two parts can break resulting in a ride home in tow truck as mentioned above.
Going up hill will also help accelerate the failure due to load on shaft changing.
In my opinion, if you notice the wobble, stop driving and make preparations to replace asap. Some said that it may cause damage in bearing on the tranny too if bad enough, thus putting you in a world of more expensive trouble.

http://www.vertexauto.com/ShowItem/2...t%20Mount.aspx

Where are you located? It might be worthwhile to take your vehicle into the nearest dealer for just a diagnostic - typically an hour of labor they would charge and find out what they say is wrong with the vehicle. You can then make a decision after they have confirmed if it's indeed the driveshaft issue or something entirely different.

 

Thank you house motor. I think you are right, It seems the bearing is failing. I will need a new drive shaft. I just don't understand why its doing while the car is turning and not when driving straight, which is the confusing part. I live in LA. I did take it to dealer (Ruznak), however they want the issue to be present to diagnose it. Unfortunately it doesn't fail while trying to reproduce when test driving with the tech, and the bearing support mount is in place (not bad). Thank you again house motor as it is most likely I would need to replace the drive shaft. I have another issue with brakes squeaking. This car is just not keeping me board at all. I had installed aftermarket front brakes and rotors few months ago, as they were in bedding process seemed there was a size difference in between the rotor (which I confirmed were the right size) and the brake pad. The pads seemed to be about a one millimeter larger than the rotors causing an overlap on the inside part of the rotor (close to the axle) which was causing the squeaking. Since the rotor size was confirmed were the large size vs the smaller size, I assumed the pads were aftermarket and were not cut precise. I ordered new set of OEM pads from Suncoast Parts and replaced the aftermarket ones. Now couple of moths later when bedding is complete or still bedding I am getting squeaking from front brakes again. I don't understand what could be the issue, could of it been the rotors were nor cut precise and I should of replaced the rotors instead. I don't think it would be a installing issue since the pads could not have been installed improperly. The confusing part is I did the same aftermarket brakes and rotors for the rear and they did not squeak at all. Than you house motors for your time in advanced I appreciate the effort you are putting and explaining things in detail.

 

Let's do this -- since you are in LA, bring the car down to our shop and I'll have our techs go on a test drive with you and let's see if we can figure out if it's the drive shaft once and for all. Just give me a call before you come on down and we'll get to the bottom of this! Also, you should be bringing your car to us for any issues and routine maintenance from here on out, we'll take great care of you and your Cayenne!

http://www.yelp.com/biz/house-automo...epair-pasadena

For brakes, we always recommend factory parts - we've found that aftermarket brake components almost always have some sort of squeaking/noises. It's possible that the rotors have something to do with the noise now that you've got new oem pads up front.

- Jason
626 539 2911