dreaded shock knock

mal1953 · Post by **mal1953** » Fri Aug 10, 2012 6:56 pm

Hello all, as topic says. I had new lowering springs fitted today and I now have nasty banging noises from rear end, took the car back to the garage and they checked that everything was tight,it seems to me that I need the extra washer fitted to take up the slack which I have read about on prelude uk, does anyone have any sizes of the washers I need, ie outside diameter, inside diameter and thickness or is the thickness to be determined somehow? Also where is the washer fitted, is it where the top part of the shock is in the boot? Many thanks for your help. ps its 4th gen bb1.

bristol_bb4 · Post by **bristol_bb4** » Fri Aug 10, 2012 7:00 pm

http://www.ludegeneration.co.uk/honda-p ... -t739.html

mal1953 · Post by **mal1953** » Fri Aug 10, 2012 7:46 pm

Many thanks bristol bb4, would you know if the ammont of washers needed is diffrent for lowered cars? Or is it a case of trial and error.

Dbo · Post by **Dbo** » Fri Aug 10, 2012 7:50 pm

when i did mine i got 3mm thick washers and fitted 2 to each so a 6mm spacer

mine is lowered 30mm on back

just remember to centre the holes in the washers over the shock collar

A1ex · Post by **A1ex** » Fri Aug 10, 2012 7:56 pm

I need to get this done too, after reading this that knocking since lowering makes much more sense!

Post by **NafemanNathan** » Fri Aug 10, 2012 8:02 pm

That cure for shock knock is actually only for when the top mount bushes are warn and slack... The washers basically make up the difference lost from the overall stack height from the bushes.

If you've suffering from shock knock after fitting lowering springs you won't be able to cure it by adding washers. In theory you want to shorten the travel length of the dampener, but by adding washers to the top on the top mount or even to the underside, all you're doing is squashing the bushes. You can't pull the dampener rod further up through the top mount which is what you want to achieve, as near the top of the rod is a shoulder that can't pass through.

Hope that makes sense.

Out of interest, what springs have you used and how low have you gone?

A1ex · Post by **A1ex** » Fri Aug 10, 2012 8:07 pm

If that questions for me, Ive got jdm tein basic coilovers (from LLL) would changing the top hats help?

h10ndr · Post by **h10ndr** » Fri Aug 10, 2012 8:12 pm

I thought both my Prelude and my bro-in-law's had shock knock until we fixed it by replacing the rear drop link bushes...

mercutio · Post by **mercutio** » Fri Aug 10, 2012 8:24 pm

h10ndr wrote:I thought both my Prelude and my bro-in-law's had shock knock until we fixed it by replacing the rear drop link bushes...

this^^^^^
check all the suspension your driving an old car unless you have replaced all the bushes/rubbers it could be anything

A1ex · Post by **A1ex** » Fri Aug 10, 2012 8:30 pm

V true! Ive got the 2ws sub frame to go on from cebul's type s which covered about 40k which may go some way to cure it as have all 4 arms with bushes

Lude Generation

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