Cluncking (kinda) Sound Under Load

[AVIA8R]

2004 Cayenne Turbo, Upsolute Chip, FAbspeed bypass pipes, and straight pipe exhaust.

Last night I pulled out of my neighborhood and when I got hard on the throttle, there was a clunking sound. It sounded like it was under the vehicle. It was similar to the sound that the engine made after I put the Upsolute chip in and raised the boost, but before I replaced the ignitors. So, I immediatly thought my ignitors were going back again. But, it was not from the engine, nor did it change in tempo or magnitude with engine speed. If I applied a load in 6 until it started doing it and then down-shifted to 5th, there was no change in the sound. So, I'm thinking it's the transmission or one of the differential.

To be honest, I'm sure I brought this on to myself. I replaced the muffler with straight pipes a few weeks back and have been down-shifting during deceleration a LOT.

Any advice? I've searched the Forum and cannot find anything.

Any help would be appreciated.

Matt :renntech:

[wvicary]

First thing to check is the centre brng in the rear drive shaft, also called a carden shaft. Then inspect that aftermarket exhaust system to make sure it's not hitting or come adrift.

[wirunner]

First thing to check is the centre brng in the rear drive shaft, also called a carden shaft. Then inspect that aftermarket exhaust system to make sure it's not hitting or come adrift.

+1 Those VW driveshaft center bearings are crap. Probably just too much for it.

[AVIA8R]

Thank you for your time. Other than the sound, is there a way looking/inspecting the driveshaft that one can tell if it's defenietly the shaft?

Agian, thank you. I greatly appreciate your time.

Matt

[wvicary]

The drive shaft is of a two piece design supported in the centre by a brng in a rubber carrier. The rubber brng support will have visible cracks or torn away completely from it's metal outer housing. This is the most common type of failure with this unit.

[AVIA8R]

Ok. Just crawled under. Now it looks like there are actually three pieces between the front grear box and rear differential.

The first section is about 1.5' long. I looked the connection area at that point and there's a rubber bushing that I can see completely through. The shaft and the out support are completely loose from eachother. Is that the bearing in question? Is that torn area my problem?

You guys are great...thank you so much. This is saving me (again) a lot of time, hassle, and money.

Matt

[mtimmy]

Did you get the problem fixed? same thing just happened to me,. it only sound loud with load, even small load ., I try to down shift at 65mph to 5 to 4 to 3.,

its the same sound with same tempo.

I even put the car in netual and it making a very small sound., so I assume its not the engine..

Ok. Just crawled under. Now it looks like there are actually three pieces between the front grear box and rear differential.

The first section is about 1.5' long. I looked the connection area at that point and there's a rubber bushing that I can see completely through. The shaft and the out support are completely loose from eachother. Is that the bearing in question? Is that torn area my problem?

You guys are great...thank you so much. This is saving me (again) a lot of time, hassle, and money.

Matt

[AVIA8R]

The clunking noise was a worn drive-shaft bearing. It holds the connection point between the two driveshats pieces. About $600.

If it's worn as mine, you'll be able to see a gap between the shaft at the bearing holder underneath the car. Mine was completely gone.

Good news is that the new one is greatly upgraded and doesn't fail as easily.

Hope this helps.

Matt

It

Did you get the problem fixed? same thing just happened to me,. it only sound loud with load, even small load ., I try to down shift at 65mph to 5 to 4 to 3.,

its the same sound with same tempo.

I even put the car in netual and it making a very small sound., so I assume its not the engine..

Ok. Just crawled under. Now it looks like there are actually three pieces between the front grear box and rear differential.

The first section is about 1.5' long. I looked the connection area at that point and there's a rubber bushing that I can see completely through. The shaft and the out support are completely loose from eachother. Is that the bearing in question? Is that torn area my problem?

You guys are great...thank you so much. This is saving me (again) a lot of time, hassle, and money.

Matt