So recently whether i press on the brakes to slow down or engine brake...once it hits around 20mph and lower a weird very light vibrating sound comes in for a good 2-3 seconds and then disappears. Now, I replaced the whole control arm kit/ tie rods and front axels about a month ago. I'm thinking the vibration is coming from my drive shaft or train? what do you think?

 

Sounds like an ABS issue. I've been reading up on this lately - do a search for "tone ring" and see what comes up. The S4 guys deal with it quite a bit.

 

No doubt this is an ABS issue. More than likely either one of the ABS sensors is damaged or simply not pushed in far enough.

 

yea i found out that when the car slows down on gear whether it be engine or pressing on the brakes the car would vibrate slighty then go away after 2-3 seconds but if i slow down on neutral whether its engine or the brakes there is no vibration...is this still an ABS issue?

 

So the car will do this vibration around 20mph whether you are pressing the brakes or not?

It's possible it could still be an ABS issue, if your car has some sort of traction control (forgot what it is called on these cars) it's possible that is activating, since it uses the ABS system.

 

yea when the car slows down to around 20 mph or lower...short vibration sound