Gen4 possible LSD problem! Help

CrunchyAdams82 · Post by **CrunchyAdams82** » Fri Mar 29, 2013 4:08 pm

Hello all,

I recently bought a '1994 Gen4 Honda Prelude 2.2 Si vtec LSD' to work on as a project. I am also using it as my everyday car.

Yesterday it started making a horrible clattering/chattering noise under low rev deceleration. The noise kind of spins up when I slow down and the engine reaches low revs, then fades down once I either get back on the throttle, or come to a complete standstill.

The noise only occurs when the vehicle is in motion - slowing down at low revs to be specific, and can happen whether the brakes are being applied or not. Coincidentally, the noise is exactly the same regardless of whether the brakes are being applied or not.

The clattering is also accompanied by what I can only describe as a 'background electrical whining'.

Perhaps most importantly, the 'spinning up' & 'winding down/fading away' characteristics are not consistent with either engine speed, or wheel speed. But the sound seems to be coming more from the r/h/s of the vehicle. Possibly close to the right front wheel. Car is R/H/D if this makes any difference.

Now, I don't know much about how LSD's work, hence my post. But the reason I believe it to be a problem relating to the LSD, is that it sounds like how I'd expect it to sound if I could hear it working. It sounds like it's working correctly, just one of the internal components is grinding, or worn out.

It sounds like gears grinding, or if you were to spin up a cog of sorts really fast, then touch it with a piece of metal or plastic.

My best guess would be a problem with overrun, and something relating to the coupling perhaps?

I really don't know much about LSD's, so I could be completely wrong about this. But either way, it doesn't sound healthy.

*It may be worth noting that the ABS light is on. I would assume that the brake pads are just low because the brakes feel a bit spongy, and perhaps slightly out of balance. But no brake related warning indicator noise to speak of. The only reason I mention it, is that where as far as I know the brakes have nothing to do with the operation of a LSD, is it conceivable that it could in some way be interfering with the normal operation of the system? Or does that simply confuse matters further? Just throwing it out there.*

Does this problem sound familiar to anybody? Is there something else obvious that it could be?

Any help would be gratefully received.

Thanks

CrunchyAdams82 · Post by **CrunchyAdams82** » Fri Mar 29, 2013 4:38 pm

Also, the ABS light is on. So I think the brake pads are probably low. Could the problem be compounded by this in any way?

Post by **vanzep** » Fri Mar 29, 2013 5:02 pm

i take it the noise is only when the car is moving? so difficult to tell what things like this are with little info. like you say could be clutch or brakes.

Post by **Pushki** » Fri Mar 29, 2013 5:39 pm

How low are the brake pads? Could be the wear indicators you are hearing.

CrunchyAdams82 · Post by **CrunchyAdams82** » Fri Mar 29, 2013 6:30 pm

Only when in motion; deceleration to be specific at low revs. Defo not clutch. Pads are quite low I imagine, but not sure how low; and have no idea what wear indicators sound like. Could be.

CrunchyAdams82 · Post by **CrunchyAdams82** » Fri Mar 29, 2013 6:34 pm

When you say 'wear indicators', do you mean the metal screechy ones that scrape on the discs when pads are low? It's not that.

Post by **Pushki** » Fri Mar 29, 2013 6:37 pm

CrunchyAdams82 wrote:When you say 'wear indicators', do you mean the metal screechy ones that scrape on the discs when pads are low?

Yes.

Post by **vanzep** » Fri Mar 29, 2013 6:45 pm

sounds like it could be chatter/grinding from worn or damaged pads or a sticking caliper - you should be able to feel the car pulling to one side

CrunchyAdams82 · Post by **CrunchyAdams82** » Fri Mar 29, 2013 6:50 pm

Yeah, it's defo not the brake pad warning indicators then. I've had those go several times before & know what they sound like. It's more of a mechanical/electrical whiney burble??!! Sounds somewhat like a noisy, abrasive hedge trimmer!!

CrunchyAdams82 · Post by **CrunchyAdams82** » Fri Mar 29, 2013 7:02 pm

The noise is not consistent with the speed of the engine or wheels. The noise can be there whether the brake pedal is pressed or not. I don't believe it to be the brakes. I genuinely think it has something to do with the LSD, but know nothing about the components that make up a LSD. It's just the 'spinning up' and 'winding down' of this noise that sounds reminiscent of what I'd expect to hear from such an application. Almost like it is working as it should be, but something to do with it is worn or knackered. Like a bearing - if applicable to LSD??