Vibration problems, help

[immortality]

got some weird vibrations happening when driving. previous wheel balance didn't fix it but it was very minor at the time so i wasn't to worried about it. gotten worse of late, thought it may have been an engine mount problem, see my thread diff problems ok, so far i have replaced the engine/trans mounts, replaced the driveshaft hanger bearing and the universals checked out ok. the orientation of the universals was 90 degrees out from where i woulda normally expected it to be but i don't think this is the problem and i've re-assembled it as it was.
there is a problem with the diff, there seems to be excessive backlash but i don't think that would be the cause of the vibration either. later this week i'm going to pull the diff centre, check the bearing etc and reset the backlash hopefully. i've recently lowered the car on lows(it's the missus daily drive) with all new shocks etc. it's also got a weird shudder from the back of the car when reversing quickly. it's always done this but it's also getting worse now. i've run outa ideas of what to check next, thinking maybe rear suspension bushes etc so far i've replaced the front and rear swaybar link bushes, panhard bushes and front raduis arm bushes top strut mounts

cheers

[r_i_d_a_h]

harmonic balancer maybe? :S

[immortality]

Originally Posted by r_i_d_a_h

harmonic balancer maybe? :S

sorry, shoulda added that there is no vibration when idling or free revving when not in gear. vibration only when driving but at different speeds and it comes and goes etc

[bradyboi]

from reading your problem, i remember scanning across the common faults in VS's... now im no expert on this and you have probably already checked this, but maybe the torque converter?

[immortality]

Originally Posted by bradyboi

from reading your problem, i remember scanning across the common faults in VS's... now im no expert on this and you have probably already checked this, but maybe the torque converter?

torque converter/flex plate should be ok cause there is no vibration when free revving it when not in gear. i will however be pulling the inspection plate off later this week to double check it

[sircruisealotVS]

so its a vibration you feel through the chassis, not just something you hear?
im racking my brain and i am thinking possibly wheel bearings?
whats the vibration like...

[The Darkness]

what speeds is this happening at? i know my vibrating problem turned out to be the torque converter and that was only when driving between 80 and 100km/hr. and at 60 when the power button was on. nothing ever when free revving or idleing either

[Not_An_Abba_Fan]

The fact that you can't feel it while free revving doesn't rule out engine components. The torque converter will act differently under load than it will stationary. Also the balance shaft has a tendancy to produce vibration under load.

[immortality]

Originally Posted by 4BDN_VR

what speeds is this happening at? i know my vibrating problem turned out to be the torque converter and that was only when driving between 80 and 100km/hr. and at 60 when the power button was on. nothing ever when free revving or idleing either

i haven't been able to pin it to any particular speed, ive noticed it right from 20 km upto over 100km, the funny thing is it's not alsways at the same speeds etc. if it was an engine/trans component i'd expect the vibration to always showat the same speeds/revs etc but i haven't been able to do this. i haven't actually tried it with the power button so i guess it's something else for the weekend

[immortality]

Originally Posted by sircruisealotVS

so its a vibration you feel through the chassis, not just something you hear?
im racking my brain and i am thinking possibly wheel bearings?
whats the vibration like...

i'ver always been of the belief and i could be wrong but if the vibration is in the front then you'll feel it through the steering wheel etc, if it's from the rear then you feel it through your butt etc. i'm definitly feeling it through the chassis, i'm still thinking that it's related to the diff somehow cause of the clunk when going into reverse and the fact that you can really feel the chassis move as the diff loads up agains the suspension/chassis as the backlash is taken up etc. wheel bearing is a possibility but i can't feel anything when turning rear wheels. but it's also on the list along with resetting the backlash in the diff etc

[Not_An_Abba_Fan]

Checked your panhard rod bushes?

[immortality]

Originally Posted by Not_An_Abba_Fan

Checked your panhard rod bushes?

yep, one of the first things i replaced when i got he car