Differential Noise HELP!!!
 

Hi There,

My Z has 50.1k miles being driven spiritually on the weekend. This afternoon I noticed a loud clanking noise whenever I reserve the vehicle.

I conducted the following tests to isolate the noise:
1) Did the noise change with speed? Yes only in reverse
2) Did the noise change going forward? No did not make any type of noise going forward
3) Did the noise change low speeds? Yes going forward I hear a click and reverse the noise is more extreme
4) does the noise happen in reverse going downhill? No noise is heard when in neutral going downhill

Do 370z diff normally go out at 50k?
How much should I expect to spend on repair?
Is this a diff problem or something else?

Could be a few things, but I would start at looking at the diff bushings.

The stock diff is fairly stout. But it is susceptible to damage if beaten on regularly and the fluid is not maintained. Could be a bearing.

The diff bushing is very prone to failure (I bet yours has), but the result is maybe noticing a bit more slack in the drivetrain, not loud clanking in reverse.

There is also a rear axle click issue that can be annoying, but I certainly wouldn't describe it as "loud clanking" (http://www.the370z.com/engine-drivet...unk-noise.html).

The 2 most common problems are the rear diff bushing and the axle click. For the rear diff bushing. Get under the car and look at the diff cover. If the bushing is shot. You should see black/brown streaks running down it. The axle click can be fixed easily. The problem is the axle nut is not tight enough. Causing the axle splines to move inside the splines in the hub.

Mine has 54k and had some noise and feels a little off.

Had it on a lift at dealer and could see that my rear diff bushing bled out, now there is a chalk outline at the scene of the crime. Time to go aftermarket for the replacements. Dealer doesn't service enough 370s to waste my time there.