Altima 05, 2.5s 4 cyl, idle vibration - rear mount?

[doronbra]

Hi all

Hope I might be able to get some help regarding my idle vibration.
I will start to say that I am a kind of perfectionist and its not a matter of very rough vibration but rather a slight vibration on idle in drive, felt in the steering wheel, pedal & seat. Sometimes it goes away but felt stronger on a cold engine. I think that it's better in moist weather condition, does that make sense?
The vibration is only in drive and parking and neutral is flawless.
Had the car for a year, it has 106k miles and I have already done the following:
1. Replaced front, transmission & passenger mounts
2. Replaced cranckshaft & camshaft sensors
3. Changed plugs
4. Did oil change and filter
5. Cleaned the throttle plate and relearned the idle

It seems I always had this vibration and it got better as I did the above but it's still there.

I have added this verio that shows the engine as I move to drive and add load such as ac and lights. I am thinking that maybe the rear mount, the only one I didn't replace, is responsible for this and I wanted to get some professional advice.

http://youtu.be/NckkQA832xE

Thanks

[sstroudwku]

A notorious cause of this is the alternator coupling has froze up. I'd be willing to bet if you remove the drive belt and retest it I would bet it goes away. If so, an aftermarket will do the same thing. Your best bet is a second hand factory unit, a new replacement is over $400.

[doronbra]

Thanks sstroudwku!

I have an ODB connector with an app on my phone and can see that the volts are around 13, it jumps slightly between 12.8 to 13.2. Would that also hint about the alt?
Would you cancel out the rear mount based on this info?

I was advised to take out the belt but I will be honest, I was reading people's descriptions of how to do it and couldn't completely follow, seems there are different ways to do it. Any straight guides you can advise for the altima 05 4 cyl?

I have read that replacing the alt is pretty straight forward, would you advise the same?

Would love to do this as DIY and would appreciate any help guides here.

Thanks again!

[doronbra]

Another quick question, I saw there are different alternators based on when the car was made (thru 12/4, frome 1/05thru 4/05 etc...). How can I check my exact model?