youguessit

Ok for starters heres what i have. 2002 a4 z28. I have prothane motor and trans mounts. It is stalled. I have this wierd vibration unrelated to vehicle speed. It is more related to rpm. It is on and off though. it vibrates for a second and then stops for a second over and over. It starts vibrating real subltle and then more and decreases the same way. I have already tried unhooking the belts and it still does it. I have checked the bolts on the converter as well. My engine is running perfectly and i have perfect oil pressure. No wierd noises. So any ideas?

conan

iTrader: (5)

have you checked your U joints in the drive shaft.

01ws666

U-joints would make it a more speed related vibration not rpm related.

I'm having similar vibration issues and cannot figure out WTF it is! At speeds under 60 the vibration is only apparent in manual 2nd or 3rd. But in drive its smooth until 60ish then the vibration starts and gets worse and worse as i go faster.

It all started after I snapped my transmission output shaft, twisted my driveshaft and blew my 10 bolt. Everything's been replaced or upgraded, new driveshaft and slip yoke have been checked for ballance, torque arm bushing -tranny mount - motor mounts have all been replace with polyurathane bushings.
I pulled the driveshaft and ran the car through the gears with it off and had vibration still. was thinking it may be the torque convertor but have the same vibration before and after swapping in a yank pt3800. flexplate was replaced with a s.f.i. approved unit... WTF else could it be?

Omec

iTrader: (2)

Youguessit - since its no speed related i wounder if its the converter. also most ls1-6 ive ever seen have always had shudder too it.

01ws666 - ive got an M6 w/ polys all around. at about 62-72 MPH i get a vibration from the rear. only between those speeds regardless of gears. seems like alot of people have that problem and have yet to fix it. UNLESS its your pinion angle thats off, bad u-joint (i know ive got one) or a tire balance issue.
Edit: sorry for somereason i thought you had an M6. im thinking maybe you shocked something in the trans, or flex plate when you you took out everything?

youguessit

LOL, i found it. My trans mount had a lil play in the bolt... Now instead of vibrating some of the time and stopping it vibrates all the time. win some and lose some lol. I guess thats what everyone complains about with the prothane mounts. Well thanks anyways guys.