Sonic ear for diagnosing gearbox noise?
Sonic ear for diagnosing gearbox noise?
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Discussion

GRynners

Original Poster:

138 posts

262 months

Tuesday 20th March 2012
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Anyone any experience of using these to diagnose the area for gearbox noise? Soemone has asked me about them - know where I can get one? A few searches has brought up nothing other than some kiddies game from years back. I assume it's something like an electronic stethoscope.

Thoughts appreciated.

GR

ridds

8,372 posts

274 months

Saturday 24th March 2012
quotequote all
www.frost.co.uk do them.

Saw one in their catalogue today £19.95.

No reason why it shouldn't work fine on a gearbox.

Evoluzione

10,345 posts

273 months

Sunday 25th March 2012
quotequote all
http://www.ebay.co.uk/itm/Mechanics-Diagnostic-Pro...

As with any tool the skill is in how you use it and these aren't as easy (in your situation) as you would first believe. The problem is that noise travels through the whole of the engine and transmission making single point identification initially quite difficult. I would recommend buying a cheap one like above (or even making your own from a length of metal rod with a plastic cup skewered on the end if you can't wait for the real thing) and giving it a go and learning how to use it by comparing pitch, tone and volume of various areas and components.

Be aware that sometimes the noise can be so harsh it can hurt your ears, so maybe dampen it by putting a lump of plastic or plasticine on the end of the probe.

GRynners

Original Poster:

138 posts

262 months

Monday 26th March 2012
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Thanks both. Not quite sure if it was what they were looking for, but the ebay one has got to be worth a punt.


ScoobieWRX

4,863 posts

256 months

Tuesday 27th March 2012
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It sounds like you need the same kind of setup as a tuner would for listening to engine knock....Electronic Det Cans!!

Bolt the knock sensor to the gearbox casing far enough away from the engine if you can, and you should be able to hear what's going on. I have a set of closed ear headphones, 12V headphone amplifer with input/output (you can buy 9V battery operated to), knock sensor with a long cable and jack plug.

I usually bolt mine to the top of the OEM knock sensor on Subarus, and i can hear what's going on no problem. I imagine you should be able to do exactly the same with a gearbox.