Clunking and violent vibration
03-12-2024, 08:06 PM
#1
Clunking and violent vibration
Hello. Been lurking on this forum for a while in anticipation of finding a clean Cayenne. I recently purchased a nice 2005 Turbo with 132,000 on the odometer. After replacing a valve cover gasket and plugs to fix a misfire, as well as changing oil, diff, and TC fluids, I've come across another issue.
When accelerating slowly from stop, I notice a slow popping sound coming from what appears to be the right rear. This feels like maybe I'm running over a few large grooves in the road but there are no grooves present. When I get up to freeway speeds, there is a violent vibration coming from what seems like that same right rear area. It sounds and feels like the truck will shake apart. It goes away when the brakes are applied but continues when accelerating again.
I initially thought perhaps there was an issue with the transfer case so I unplugged the TC control module from underneath the passenger seat. Since then, the truck drives like butter and there are no issues. No codes were ever thrown on the dash and nothing comes up on my scanner except for a few unrelated AC and purge valve codes. I also thought this could be related to the driveshaft but like I said, it runs fine now that the TC module is disconnected, albeit with only the rear wheels getting power. Is it possible that the transfer case is shot or could it be chalked up to something else such as a front driveshaft issue? I've done some research regarding the TC stepper motor but most of the people with that issue report noises when turning. I have no such issues when turning.
Any help or ideas would be appreciated.
When accelerating slowly from stop, I notice a slow popping sound coming from what appears to be the right rear. This feels like maybe I'm running over a few large grooves in the road but there are no grooves present. When I get up to freeway speeds, there is a violent vibration coming from what seems like that same right rear area. It sounds and feels like the truck will shake apart. It goes away when the brakes are applied but continues when accelerating again.
I initially thought perhaps there was an issue with the transfer case so I unplugged the TC control module from underneath the passenger seat. Since then, the truck drives like butter and there are no issues. No codes were ever thrown on the dash and nothing comes up on my scanner except for a few unrelated AC and purge valve codes. I also thought this could be related to the driveshaft but like I said, it runs fine now that the TC module is disconnected, albeit with only the rear wheels getting power. Is it possible that the transfer case is shot or could it be chalked up to something else such as a front driveshaft issue? I've done some research regarding the TC stepper motor but most of the people with that issue report noises when turning. I have no such issues when turning.
Any help or ideas would be appreciated.
03-13-2024, 10:51 PM
#3
Thanks for the response. From what I've read it could very well be the stepper motor. I've seen some conflicting info regarding whether or not it's necessary to replace the control module along with the motor. Did you replace the module as well?
03-25-2024, 07:18 PM
#4
Replaced the stepper motor with a new unit. No change in behavior at all. Still starts shaking violently at about 50mph. From what I've been reading, sounds like it may be a stretched transfer case chain.