Low RPM vibration
 

As title says, under deceleration (engine braking) in any gear there is a vibration when the needle falls around 2300-2100 RPM. Not apparent above or below this range. You can feel it in the wheel and even hear it a little too (but only just), almost feels like there is a very slight resistance.

Thinking it could be from the diff, I can't feel anything particular coming through the knob if I rest my hand on it.

I have put almost 16k on the car since picking it up in December last year, (now at ~43k) and am thinking a diff fluid flush might help? (service manual says replace at 60k)

Has anyone else experienced this? Should I look into replacing the oem VLSD? Any input is appreciated.

check your Differential bushing could be collapsing

http://www.the370z.com/engine-drivet...l-bushing.html

Bet the rear subframe diff bushing failed. Look for evidence of fluid leaking out where the diff connects to the subframe (see pic in the link above). Dealer will want to replace the $900 subframe plus the bushing and stupid amounts of labor :shakes head:

Just take it to a decent shop and they should be able to replace just the bushing for a couple hundred plus the Whiteline diff bushing set is like $100. Don't put in another fluid-filled OEM bushing that could just fail again.