'clacking' Noise From Underneath Car

[OzyNick]

Hi. I'm OzyNick and new to this forum.

We have a 1990 (ish) Skyline Automatic.

It's always run well and given no trouble.

Coming home from work the other day it started making a loud tapping or clacking noise. Imagine a small jack hammer or some metal object interfering with metal spokes. I'm sorry but it's best description I can come up with. The sound seems to be roughly under the driver or further back. It's definitly NOT the motor. I imagined maybe the diff?

For the little time we drove it, the car seems fine. Accelerates smoothly, no vibration of any kind, stops fine. Except for the evil sounding noise it seems fine.

The problem is this. I need to get the car to our mechanic, about 10 - 15 easy klm away. But is it a good idea to drive it that far?

Can anyone here at least suggest what the fault might be? And could (should) the car be driven.

I know it's hard not seeing and hearing it your self but maybe the symptoms sound familier?

Thanks in advance for any help at all!

[Daleo]

Hi. I'm OzyNick and new to this forum.

We have a 1990 (ish) Skyline Automatic.

It's always run well and given no trouble.

Coming home from work the other day it started making a loud tapping or clacking noise. Imagine a small jack hammer or some metal object interfering with metal spokes. I'm sorry but it's best description I can come up with. The sound seems to be roughly under the driver or further back. It's definitly NOT the motor. I imagined maybe the diff?

For the little time we drove it, the car seems fine. Accelerates smoothly, no vibration of any kind, stops fine. Except for the evil sounding noise it seems fine.

The problem is this. I need to get the car to our mechanic, about 10 - 15 easy klm away. But is it a good idea to drive it that far?

Can anyone here at least suggest what the fault might be? And could (should) the car be driven.

I know it's hard not seeing and hearing it your self but maybe the symptoms sound familier?

Thanks in advance for any help at all!

Does the noise speed up and slow down with the speed of the car?

If so; you might've got a bit of wire caught around the tailshaft.

If you have a set of ramps or a jack, look underneath. If not; park with the two left side wheels up on a gutter and slide underneath for a look. Could be really simple.

Edited March 21, 2012 by Daleo

[GTSBoy]

Do you have any bastard friends who'd think it's funny to put a cable tie around your tailshaft or driveshaft?

[OzyNick]

I've checked that already Daleo and nothing there. However your spot on about the sound, it sounds just like that!

Does the noise speed up and slow down with the speed of the car?

If so; you might've got a bit of wire caught around the tailshaft.

If you have a set of ramps or a jack, look underneath. If not; park with the two left side wheels up on a gutter and slide underneath for a look. Could be really simple.

[Daleo]

I've checked that already Daleo and nothing there. However your spot on about the sound, it sounds just like that!

Might be a tailshaft uni joint or a centre bearing.

I had a centre bearing in my old R31 that would do that only in reverse and only when the car was stone cold.

As the joint warmed up; the tiny amount of grease still inside would move around and quieten the noise.

Look for grease nipples on the uni's, give them some love; if no nipples; you might have to undo the shaft to check for wear. A dry uni can be hard to diagnose until it starts to wear significantly.

Good luck.