How do I know when my CSB has crapped out?

[JPL]

might be a stupid question but when I am on the freeway at high speeds I get a loud hum and some bad vibrations. I am perplexed as to what could be the problem. Does my crank shaft need to be balanced?

any ideas where I should specifically investigate?

Jake

[jlevie]

The usual failure mode for the CSB is a failure of the rubber mount, which will cause thumping/banging from under the car during hard accelerations (especially in the lower gears). And the cause of that is almost always a failure of the drive shaft u-joints. This sort of failure is easily diganosed by a visual inspection of the CSB. Rarely, the CSB bearing can fail and that can only be diagnosed after removing the drive shaft.

A failing guibo can cause vibrations (again subject to a visual inspection). Speed dependent noise from the drive train can also be caused by the differential, wheel bearings, or tires.

[JPL]

my car had the wheel bearings changed at 88,000 miles and there's now 106,000 on my car. the guibo was changed at 97,000 miles. and a few months ago i put in an 3.73 lsd. tires were put on new at 103,000 and i doubt they need balancing already. could be the diff i guess.

whats involved in fixing the diff and what would need to be fixed? considering i have speed dependent noise from the drive train

[HST]

The noise:
-Sounds like the wheel from "wheel of fortune".
- Correlates to wheel rotation, not RPM.
- Really loud, undrivable.
- Pretty much constant, happens loud under braking, intermittent during turning.

According to the GF outside car:
Comes from underneath the cabin, equally loud on both sides. Like it's coming from the driveshaft tunnel.

When I jacked up the rear of the car and turned the wheels, there was a slight noise coming from the driveshaft underneath the exhaust.

http://www.r3vlimited.com/board/showthread.php?t=87401