Porsche Cayenne Forums banner
1 - 8 of 8 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter · #1 ·
Hi, I'm new to the forum but had our 955 S many years now...

After fording 2 feet of water a few days ago I now have a metallic whine that is evident with increase in road speed.

The tip-tronic shifts are normal as is switching in and out of low range.

Brakes all feel normal and have been power washed to be certain.

Thoughts would be very much appreciated.


GEN 1 955 S, Air Suspension.
 

·
Administrator
Joined
·
28 Posts
The most vulnerable bearing in a 955 would seem to be the center bearing on the cardan (front to rear) driveshaft.

If it is directly related to road speed (vs engine speed) - then it's somewhere in the driveline. It may require getting it on a lift and running it (remember to turn off the air-suspension before lifting it) while checking underneath using a mechanic's stethoscope (available cheaply in the US from a discount tool place - Harbor Freight).
 
  • Like
Reactions: CayenneLife

·
Registered
Joined
·
4 Posts
Discussion Starter · #3 ·
Thanks for your response, I forgot to say that I replaced prop/drive line 2 to 2.5 years ago... Any suggestions for how to hang under the car with a stethoscope? :geek:
 

·
Registered
Joined
·
6 Posts
The other bearings to consider would be in the front differential carrier. Both my 955 and 958 had a whine tied to road speed (it changed pitch accelerating vs decelerating). On the newer one, I ended up replacing the front diff with a factory reman and things have been quiet ever since. The replacement wasn't as bad as feared and in hindsight I probably could have just replaced the worn bearings, but I wanted to minimize vehicle downtime and was not 100% confident about setting diff preload, etc. I would think a good 4x4 shop could handle it...
Ed
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #5 ·
The other bearings to consider would be in the front differential carrier. Both my 955 and 958 had a whine tied to road speed (it changed pitch accelerating vs decelerating). On the newer one, I ended up replacing the front diff with a factory reman and things have been quiet ever since. The replacement wasn't as bad as feared and in hindsight I probably could have just replaced the worn bearings, but I wanted to minimize vehicle downtime and was not 100% confident about setting diff preload, etc. I would think a good 4x4 shop could handle it...
Ed
Thanks for this info, would it be possible for this to happen right after fording water as it seemed a little coincidental.
 

·
Registered
Joined
·
6 Posts
Thanks for this info, would it be possible for this to happen right after fording water as it seemed a little coincidental.
If water got inside the housing it could compromise the diff fluid. Have you tried draining and replacing it? If it looks milky it got mixed with water. Also, you should see shiny dust or flakes if your bearings are damaged. I would check both the transfer case and the differentials - changing the fluid isn't too difficult and it won't hurt to have new, clean fluid in them.
 

·
Registered
Joined
·
3 Posts
If water got inside the housing it could compromise the diff fluid. Have you tried draining and replacing it? If it looks milky it got mixed with water. Also, you should see shiny dust or flakes if your bearings are damaged. I would check both the transfer case and the differentials - changing the fluid isn't too difficult and it won't hurt to have new, clean fluid in them.
Thank you. Evidently there was no evidence of water in the old TC fluid. from What I was told, Porsche had given no guidance on TC fluid change frequency when the Cayenne’s came out. Evidently there is one now.
 

·
Registered
Joined
·
6 Posts
Good news! Did the TC fluid change affect the metallic whine sound? If no, maybe check the front differential fluid. On my 2014, the drivers side output shaft bearing (at the end of the "long arm" of the differential carrier) was shot.
 
1 - 8 of 8 Posts
Top