Low RPM Vibration Diagnosis

[Tonggi]

Just some background info. Car has 93k miles. Rear subframe reinforced with Vincebar and plates.

Diff bushing Poly, Subframe solid, ball bearing rtabs, and spherical upper bearings. fairly fresh guibo. Poly motor and trans.

STOCK and old driveshaft.

I am driving and in 2 & 3 gear mostly. at around 2000-3500 rpms the drivetrain started shaking. Like a small vibration out of the ordinary that I know of. During idle NO vibration that I notice.

Is this a symptom of a bad Center Support Bearing? What are signs of a bad driveshaft?

I am thinking of getting the JXB Center Support Bearing, anyone have any experience?

https://www.jxbperformance.com/products/p/bmw-e36/e46-3-series-center-support-bearing-carrier-upgrade?srsltid=AfmBOor5nRoV91GYDeSTgQVZIHhh_fPnsHhmCQAUqvxXpQLa2X2ecpip

[Flow]

If it's the CSB it's speed related and not RPM related.
If you have the same vibration at the same RPM in different gears then it comes from the engine.

[maupineda]

That bearing support will just bring you extra noise and harshness.

it can also be your clutch and flywheel assembly out of balance. If you rev to that rpm range stationary, does it vibrate?

[Tonggi]

If it's the CSB it's speed related and not RPM related.
If you have the same vibration at the same RPM in different gears then it comes from the engine.

I will need to check this. Its the shifter where i feel the vibration coming out of. which is direct connect Kinematic connector.. with poly trans mounts. What can be it be form the engine. No CEL.

That bearing support will just bring you extra noise and harshness.

it can also be your clutch and flywheel assembly out of balance. If you rev to that rpm range stationary, does it vibrate?

I am ok with the NVH. I will check if it vibrates when revving.

[Flow]

I'd bet on the flywheel / clutch plate if RPM related.
Engine vibration damper is not probable as the engine would have grenaded itself already I believe, but I don't know enough about that.