I know that there is another vibration threat on here...however, I believe my question is more advanced than just "why is it vibrating".

Ok, the car vibrates over 40mph. It is a constant vibration once over 45mph but not always as strong. I turned the car off while driving and left it seating in drive and the vibration remained, then I started the car again and turned it off but this time with the car in neutral and the vibration disappeared. Also, i feel the vibration coming from the radio-shifter center area of the car and towards the back seat.. So what am I looking at here , the drive shaft? Where do I look first? What do I check for? Should the drive shaft have any play while installed? Or it should not move at all? Thanks

 

First thing I would look at are the motor mounts and transmission mount, common problem they are rubber and therefore crack ,perish and break.
Start the engine then get someone to rev it while you look at it, there should be very little movement side to side, if the engine is rocking all over the place it's a good sign the mounts have gone, transmission is easier to see and check its condition.

 

Welcome to our forums,,, for future reference and faster help, please provide up with the year of your car. I looked it up in your profile, so I now understand we are talking about your 96 LS.

There are ALOT of variables whenit comes to vibration with these cars so lets start with the simpliest ne first, wheel balance. Lexus' are SUPER SENSITIVE when it comes to balance issues, so this is the first area that i would check. Next is an overlooked item, and that is the driveshaft bushing. Considering you feel thevibe from the shifter and you seem to have isolated it to the rear of the car, this could be the issue. A worn dirveshaft bushing will cause all kinds of crazy vibe, I found out the hard way, but these 2 items Imentioned above are themost common, as well as the cheapest items to address first before you start to throw money and parts at the car. Mounts, as mentioned above, willbe the next item to have looked at. Use the method described in above post to visually inspect yourself. Have these items checked first, and addressed if necessary. Report back if the problem still exists.

 

I have vibrations and clunks. Im too lazy to fix it or even look into it.

 

Like Trukn1 said, check the wheel balance. I currently have vibration also when I drive over 55 mph and I checked the inner barrel of my rims and lo and behold, a clean square from where a weight used to be.

 

I apologize for not posting the year of the car, I'm used to using the forum for my 90-96 300zx which is very similar to this one on looks. I purchased this car back in july and so far have not done anything besides changing the fan bracket and K&N intake.
My front passenger tire is bald on the outside, only the passenger side, not the driver side. tomorrow im getting better tires since it is raining nonstop here in SoFla and the tires are very sensitive during take offs and cornering. I dont think the vibration is coming from the tires since it goes away with the car off and in neutral. Is there a specific way on removing the driveshaft? or can i just use lexls.com for tutorials on all these mounts I need to check/replace? Thanks