Hi I keep hearing these knocking sound and vibrations f...

Hi I keep hearing these knocking sound and vibrations from underneath the vehicle when accelerating, I've changed the drive shaft like twice now but still experiencing the same problems. Please I need solutions! Mechanic's A...

Hi I keep hearing these knocking sound and vibrations from underneath the vehicle when accelerating, I've changed the drive shaft like twice now but still experiencing the same problems. Please I need solutions! Mechanic's Assistant: Where exactly do you think the noise is coming from? And how long has this been going on? Underneath the car, on the passenger side. Mechanic's Assistant: What is the make/model/year of your car? 2008, volkswagen passat FSI Mechanic's Assistant: Are you fixing your Passat yourself? What have you tried so far? I hired a mechanic, and I've tried a new break disk, new bearings, new shaft Mechanic's Assistant: Anything else you want the Mechanic to know before I connect you? Not really, except that before this knocking sound my old shaft grease plastic-really don't know what it's called, worn out and the bearings were exposed and a little bit dry.

Automotive Expert
Welcome to JustAnswer. Thank you for contacting us for assistance with your vehicle. I'm Pete. I will be happy to assist you with your question. May I ask to whom I have the pleasure of speaking with today?

Famous, my name is Famous
Automotive Expert
Hello Famous. Nice to hear from you today! I'm sorry to hear you are having this problem. I know this can be frustrating. Were the engine and transmission mounts checked for any damage at all?

Yea.... But no faults, engine is fine and transmission is very ok.
Automotive Expert
Do you know if the bearings that were replaced were the bearings that were exposed to dirt or road debris?

Automotive Expert
Does the transmission shift and operate properly?

Not sure, but my bearings wear replaced, the full drive shaft on the passenger side was replaced
Automotive Expert
Thank you for your reply and that information as this does help me better understand the situation. Please give me one moment to type out some info for you. I’ll be right back!

Yea.... Except that it bumps once a day or less but all gears shifts very well
Automotive Expert
Thank you for holding Famous! Since the noise is coming from under the vehicle and since at one point there was bearing damage that had to be replaced, this type of noise and fault can be caused by an internal mechanical fault in the transmission itself. There may be other internal bearings or gears that are failing that is causing this noise that has to be replaced. I recommend having the engine and transmission mounts double checked to make sure none of them are worn, broken, or collapsed needing to be replaced. If the mounts are found to be o.k. then the transmission itself will need to be inspected internally to identify the issue so it can be repaired properly. This can cost over $1000 to have it inspected and repaired by a transmission repair facility.

Also, this knocking sounds and vibrations that I hear and feel in the stirring and underneath the car started after trying to add lubricant/grease to the old shaft
Automotive Expert
If this occurred after adding grease to the old shaft, I recommend having the shaft and transmission inspected for any mechanical issues. I do suspect that this will be a fault with the shaft itself or transmission. If you did not receive my answer I posted for your question a few minutes ago above, let me know and I can post it below again for you!

Automotive Expert
Your welcome! Glad I could be of some help! I hope everything works out well for you! If there are any additional questions on this issue that should arise, please feel free to reply and ask! Thank you for choosing Just Answer for your questions. Have a great day!

What others are asking

How do I select an MP3 or WMA file?
If you are playing an MP3 or WMA disc, then you can easily select a file to play: 1. Press the selector knob until it displays a folder list. 2. Rotate the selector knob to choose a folder. 3. Press...
Hello, Im having hard time with choosing vehicle for work
You did not mention what motor or transmissions either of the vehicles have. These are the biggest and most expensive repair concerns on any used vehicles. Firstly, I would not recommend buying a used vehicle (https://www.yourmechanic.com/article/how-to-buy-a-used-car) without having a qualified...
Breaks don't work without a lot of pressure, and is puttering when it is on
If unusual effort is required to depress the brake pedal, to get the vehicle to stop, that is often due to a fault in the brake booster or the vacuum supply and check valve in the booster circuit. If you...
Car makes what I would describe as a helicopter noise under the hood when I step on the gas; it's worst when changing gears.
Hi there. If you added three quarts of oil to your engine, it is very likely that you may have internal engine damaged; possibly in the cylinder head hardware like lifters; as that is what typically makes a constant clicking...
Wheres the 89 grand marquis fuse box location?
There is a fuse box below and to the left side of the steering column. That fuse box is covered by an access door that is part of the dash. In addition, there is a fuse box in the engine...
Car dies when AC is on
It sounds like you may have a damaged AC compressor or compressor clutch. As you may know the AC Clutch is the pulley that spins with the Belt. There are two ports on the rear of the Compressor. One is...
My 2001 Acura MDX is stalling intermittently. It usually takes a jump start to get it going again.
It sounds like you may have a weak battery, a failing voltage regulator or failing alternator. As you may know, the alternator charges the battery while the engine runs by generating amperage and recharging the battery while the engine turns...
Getting a check engine code too much air detected.
These vehicles had problems where the fuel tank causes no start after refill and there is a warranty extension on this problem and should contact the dealer to verify if covered under the failure. If it is then have problem...
Speed wont go above 60mph no matter if i step in the gas. Please help.
Hi Otto. Thanks for sending in your question. Typically when the car will not accelerate past 60 MPH, it’s due to either the ECU activating a limp mode or other mechanical (fuel or ignition system component) failures. Some of the...