Preventing rattle on shorter springs

[adam g]

I have just fitted slightly shorter coil springs to my UR but have found the Koni shocks I have do not have enough adjustment on the top threads to screw the upper spring perch down onto the shorter spring when the shock is at full extension. This means if the shocks reach full travel the springs will rattle about.

What options do I have to fix this. I'm pretty sure there are shocks out there that do have some adjustment range to suit shorter springs but as my Konis are in good nick Im reluctant to buy 4 more.

Can I use helper springs and does anyone know a source for them that will fit the standard suspension strut /perch for a UR quattro.

Any other ideas? Thanks.

[booested4door]

what koni's are they?

[adam g]

They are yellow sports shocks but have been on the car since I bought it (20 years ago).Part numbers are 86 2086 sport 0898.

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[Quattro Dan.]

Loose springs.

If you are using the standard UR struts/legs, then the way to solve the issue is to buy shorter travel shock absorbers (not ideal as you did not want to buy new shock absorbers).

If you have coil overs fitted (2.25" or 2.5" dia.) then you can fit assister springs which would solve the loose spring under full droop conditions.

Some people do not consider it a problem as it's not often that the shock absorber is at full droop.

Hope this helps,

Dan.

[John.]

Some people do not consider it a problem as it's not often that the shock absorber is at full droop.

Agreed, but some MOT testers may not see it this way though?

[Lago Blue]

Isolating the issue...

Adam,

I'm afraid I agree with the MoT folks who would view the above disfavourably. What is the vertical distance (clearance amount) you need to take up?

Something I did (years ago now!) to my slightly lowered B3 & stock B4, front & rear, upper & lower spring perches was to make tough plastic plates to isolate the springs from the perches themselves. Being otherwise stock, these raised the car on the suspension by the plate thicknesses at all occasions, not just full droop, as I did not have your issue; however something similar might suit your situation.

These plates where installed to remove the metal to metal contact of the stock spring fixturing, to quiet the suspension and to slightly de-couple the damper-axis from the efffective spring-axis. I still view the co-incident slight lifting of the cars as an advantage.

Link to my road test impressions at the time afterwards:

http://www.audiworld.com/forums/audi-90-80-coupe-quattro-cabriolet-22/enroute-report-b4-oem-front-suspension-totally-suspended-plastic-2129159/

[adam g]

Thanks for the suggestions, I really dont want to live with springs banging about on full droop, I need to make up about a 15mm gap then I was thinking another 10mm to enure some spring compression so 25mm total.

The springs I have are stiffer for the same ride height so fitting spacers would increase the ride height over standard which I would rather not do.

This leaves new shocks, not sure how Id go about finding some that would fit the struts while reducing travel by 25mm. I have contacted a couple of konis suppliers and service agents on the issue but no solutions have been forthcoming, might be time to look at other makes of shock absorber.

[Colesy]

See if you can find some Bilsten B8's, they are especially designed for lowered cars and have shorter piston rods so would probably do the job.

[newsh]

If you have re-buildable shocks you can fit a spacer inside to reduce travel

[Lago Blue]

Bilsteins for shorter springs

The Bilstein's site used to have a very good and more specific explanation of what reduced ride height they where aiming to accommodate with their B8 damper (reco'd for use with shorter springs, it can also be used with regular height springs BTW, it is a re-valved version of their B6). IIRC, 25 -30mm (below OEM non-sport spring ride-height) sounds like what they where targeting.

[Bowie69]

Hose clamps to hold the spring in place? Works on Land Rovers

[psiconauta911]

How about cutting the shock spigot where the thread is and do a new thread making the shock shorter by the amount needed, I´ve seen it done but it´s probably dumb, just an idea though!

[adam g]

Hose clamps to hold the spring in place? Works on Land Rovers

Now I am liking the sound of this. Simple and cheap. Ive just googled it and it seams spring retainers made from a simple bracket to pin the spring to the pearches are common in the off road communities.


There are plenty of holes in the spring base already to accomodate a nut and bolt or slide a hose clip through and I could easily drill a hole in the top perch.

Can anyone think of a good reason not to.

I have since found that Bilstien B6 can fit without further mods but that would cost a lot more.

[John.]

Can anyone think of a good reason not to.

Nope!.......other then when the car is jacked up for maintenance, are you really going to be driving it where the suspension is going to be at it's max?
Why not do this and see how you get on, if anything it'll buy a bit of time 'till you decide if changing the shockers is required?

[adam g]

Im not in the habit of going airborne over hump back bridges, (the last time I did that I ripped my intercooler off when I landed), but some people experience springs banging just from going over speed bumps and there are plenty of those.

As you say, no harm in giving this a whirl.


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