CRAPP!! weird vibration, PLEASE PLEASE Help!!!!!!

[87-325ic]

Alright well.. I just got the car back together good, and i went for a test drive.. All seemed good, until i got to rolling down the street and i got a horrible thumping vibration..

I first thought it was my driveshaft (anything guibo back area) due to how it felt.
It Comes from the front of the driveshaft tunnel, right near the tranny and your feet.. but it Definately is not DriveShaft related, Since.. it does it in Neutral and/ or stopped completely. Hmm??

It's been on jackstands for almost 2 weeks, as ive been doing alot of things to it..
I've Recently replaced/ Done: (in order of how much i think they could be it)
IE urethane mounts (torqued to 40ish Nm as specd , they almost deformed just a little as they got tight)
Guibo/ CSB/ rear TRANNY SEALS (maybe its caused from the tightening of the output flange collar nut as i need to hold the crankshaft bolt in place??)
Replaced tranny and Diff fluid with redline oils..
Drained and Re-filled Power steering fluid ?
z4 short shift and all new bushings
IE catback, Exhaust flanges and gaskets up to manifold
ebrake rebuild (pads, springs, and cables) Should Have Nothing to do with it..

i dont understand what it could be...

I cant feel it until about 1500 RPM, then about 2000+ it gets really noticable and worse as RPMs increase..

i really fear its something in b/w the crankshaft and transmission, as i raised and lowered the tranny mounts alot in my processes.. as well, i turned the transmission/ Driveshaft in neutral alot too..

Please help me out with any solid suggestions..????

Thanks.. :???:


(edit, I Definately think it is a little worse "while under load". What i mean is that it is more noticable around 1100 RPM while starting out in second from a slow roll, than it is stopped and in neutral at that same 1100 RPM.. )

[rede30]

I have to say this just because its happend to me... Did you check your lugs? check your center support.

[porsche gt1]

I would say your tires are off balance. I would get them rebalanced.

[HST]

I vote center support or tranny mounts or guibo

[87-325ic]

i vote everyone of you do not read!

IT HAPPENS STOPPED AND IN NUETRAL, THEREFORE THE DRIVESHAFT OR GUIBO DOES NOT SPIN......

right?

[bwanac]

Motor Mounts?

[arsevader]

i vote everyone of you do not read!

IT HAPPENS STOPPED AND IN NUETRAL, THEREFORE THE DRIVESHAFT OR GUIBO DOES NOT SPIN......

right?

Correct.

Simple rules to follow. Overly simplified but gives you an idea.

Road speed related > Things rear of the output shaft
Engine Speed related > Things forward of the output shaft

[87-325ic]

motor mounts are relatively brand new stock replacements from a few months ago,


Right, i knew it was not driveshaft related, and Clearly stated that, but the first 3 responses were completely retarded based on that... sorry.

[porsche gt1]

I still think your tires are out of balance.

[SchnellerVert]

I still think your tires are out of balance.

While stopped? Yeah ok lol.

[87-325ic]

i think you smoke too much BC Bud.

[DanielHStout]

I already love this thread.... HAHA +1 for motor mounts. Does it get any worse or shudder when you turn the AC on?

[87-325ic]

i havent checked the A/C but that shouldnt have anything to do with it,

Motor mounts ARE BRAND NEW stock replaced about 2 months ago.

i Really feel it is in the rear crankshaft area.. from when i held the front crank bolt while the tranny output flange was tightened..

i REALLY FEAR that i may have twisted the crankshaft, or as someone else suggested, messed up the flywheel or something related.

This NEVER happened before i started all this maintenence..

http://www.e30tech.com/forum/viewtopic.php?t=30686

see ^here^ for the other comments and replies on this topic..


thanks for any more help..

[porsche gt1]

While stopped? Yeah ok lol.

LOL, missed the part where the car was stopped part (putting down the Gange now)

[porsche gt1]

So now that I know the car is stopped and it is not driveshaft realted. I would say it is your urethane mounts (yes specifically Urethane). I know a couple guys that had problems using urethane mounts, they had to put spacers at the top and bottom of them to prevent them from breaking. Take a peek to see if they are cracked.

If it is a shudder all the time, your mounts have got to be the problem.(see when I put the gange down I think properly :) )