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Sinking Suspension Springs


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#1 WoodyWagon

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Posted 09 July 2019 - 04:18 PM

I'm running into this issue where the front of my car keeps sinking until its on the bump stops. Previously I have yellow SRacer spring installed and right from the get-go I had this issue, I would jack up my trumpets and the car would continually sink after a quick run around the block until its back on the bump stops. I would jack them up more and get the same results. When I look at the spring it just seems to be compressing it more and more, leaving a very small amount of space between the coils.  

 

This year I picked up a set of red springs and have run into the exact same issue. Although it seems much more pronounced, where by when I jack it down, it looks like a gasser with the front way up in the air. After a few drives its back to compressing the spring and ridding on the bump stops.

 

I run lowered gaz shock and have the larger a-arm bump stop (cut down somewhat) I don't feel this is a problem as I have tons of droop when jacking the car up?

 

Any clues what's going on here?

 

Edit: its a 68? smooth roof, external tank woody wagon. Seemed to have been dry suspension before. Now has a 1380, SC 7-port (not sure that matters)


Edited by WoodyWagon, 09 July 2019 - 04:23 PM.


#2 Steve220

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Posted 09 July 2019 - 05:34 PM

You're not going to receive positive praise on here for using springs. I'd personally replace them with proper cones and go from there. It sounds like your springs aren't the right rate.

#3 cal844

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Posted 09 July 2019 - 05:34 PM

If you have coil springs fitted, the best place for them is the scrap pile.

Personally I'd renew the upper suspension arms, knuckle joints and cups and obviously new cones, I'd recommend red spot all round... and then clean and paint the subframe and under the arches etc to try and keep the rust at bay.


Fitting new cones alone will transform the car.

Nicklouse or Moke Spider have images of what happens to coil bound springs 🤢
Post edited

Edited by cal844, 09 July 2019 - 05:37 PM.


#4 WoodyWagon

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Posted 09 July 2019 - 06:36 PM

So perhaps I should have been much more clear. The car is fully restored and basically everything on it is new or refreshed. As much as cones may be favoured the fact remains that I have springs right now and for the rest of the season due to budget restrictions. Many people have successfully used springs and wasn't looking for advice on changing but wondering if others have experienced this, if its common, why wouldn't it work when it seems to work for others, etc. 



#5 cal844

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Posted 09 July 2019 - 07:00 PM

It will always happen sooner or later as the metal fatigues faster than the rubber.


The knuckle joints might have worn through the top arms. You'll need to strip it and have a look below the knuckle joint cup

#6 Moke Spider

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Posted 09 July 2019 - 07:12 PM

There is usually some settling of any spring, be it coil or rubber from when initially fitted, however, the coil springs settle very quick and usually on the first 'go'.

 

I've not struck the issue you are seeing and it is an odd one - maybe.

 

One thing it maybe is if the machined sockets in the front arms, that the knuckle joint fits in to are worn in their base, the plastic cups will wear through rather quick as their bases are unsupported.

 

The other thing it that comes to mind is the tower tops on the subframe have cracked, though, I wouldn't expect both sides to have gone.

 

 

In regards to the Coil vs Rubber Cone 'debate' can I suggest you keep an open mind about the subject. For what it's worth, I do like the idea of Coils and looked in to it many years ago, and worked closely with a Coil Spring Manufacturer and their Engineer to see just how this could be done. After some months of trying all many of things, we found that in order to have the full natural travel of the suspension arms, the short of it was it couldn't be done with Coils.

 

Many (but not all) on the forum who have tried coil springs have reverted back to the rubber cones as they found out (and some the hard way) exactly this. When the Hilos are adjusted to a normal height, the Coils will bind before the Arm reaches the Bump Stop or soon there after. When that occurs, huge loads are transferred in to the Subframe tower and they usually break off, or, if you are lucky, the coil will break or the hilo bend.

 

Here's one from a big collection of photos I have of issues from coils;-

 

vw2qiiW.jpg

 

As I suggest, keep an open mind on it.



#7 WoodyWagon

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Posted 09 July 2019 - 07:31 PM

My mind is open, its my wallet that's stuck closed right now :X You've given me a few things to look at, although I just had it all apart last weekend and nothing jumped out at me, but it would be easy to have overlooked the bottom of the plastic cups or the beginnings of subframe separation



#8 nicklouse

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Posted 09 July 2019 - 08:53 PM

If you are getting suck down then you have too much rebound set on your dampers and it is overcoming the spring force jacking the car down in use. Park up and the car will slowly rise back up again. Much harder to happen with rubber as the spring rate rises.

Sorry but get another reason coils are really track only when it comes to Minis.

#9 Dusky

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Posted 09 July 2019 - 10:10 PM

Out of interest, what make are the springs?
Whether or not springs are good in a mini doesnt matter atm, this shouldn't happen regardless.

#10 timmy850

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Posted 09 July 2019 - 10:24 PM

Does the kit come with different front/rear springs? Just wondering if the rear springs are softer and they’ve ended up on the front?

How much space is left between the coils when the suspension is fully compressed? It’s possible the height adjustment is just set too low?

#11 nicklouse

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Posted 10 July 2019 - 12:12 AM

Out of interest, what make are the springs?
Whether or not springs are good in a mini doesnt matter atm, this shouldn't happen regardless.

It can happen with rubbers as well. But people are less likely to wind on more damping with rubbers.

#12 WoodyWagon

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Posted 10 July 2019 - 12:34 PM

Out of interest, what make are the springs?
Whether or not springs are good in a mini doesnt matter atm, this shouldn't happen regardless.

The original springs were sracer yellow, which were a fast road/rally type. I still use these in the back and haven't had any issues there. I just recently swapped the front to red springs that you find at places like mini mania or 7ent.

 

 

Does the kit come with different front/rear springs? Just wondering if the rear springs are softer and they’ve ended up on the front?

How much space is left between the coils when the suspension is fully compressed? It’s possible the height adjustment is just set too low?

The original sracer springs only had a fitting spacer for the rear, which is an adapter or more like a buffer for the small dome in the rear subframe. The original srace (yellow) front springs didn't have any spaces. The replacement red ones did and I tried them with and without. This spacer is made to go in between the trumpet and spring to provide a tighter fit.

 

 

If you are getting suck down then you have too much rebound set on your dampers and it is overcoming the spring force jacking the car down in use. Park up and the car will slowly rise back up again. Much harder to happen with rubber as the spring rate rises.

Sorry but get another reason coils are really track only when it comes to Minis.

This is an interesting thought and will take a look at this, I have lowered Gaz shocks that are adjustable. Maybe I'll back them right off and see if this alleviates any of the issue.


Edited by WoodyWagon, 10 July 2019 - 12:36 PM.


#13 nicklouse

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Posted 10 July 2019 - 01:13 PM

It ain’t a though it is a fact.
A dampers job is to control the motion of the wheel. If the wheel is not being allowed to return to its normal position in an acceptable time then there is too much damping.

The same as when you follow a car and a wheel it bouncing over ever bump and continues to bounce. Not enough damping (or blow damper).

A damper does not control the body movement that is the job of the spring medium (as well as holding off the ground).

#14 Bobbins

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Posted 10 July 2019 - 01:52 PM

It ain’t a though it is a fact.
A dampers job is to control the motion of the wheel. If the wheel is not being allowed to return to its normal position in an acceptable time then there is too much damping.

The same as when you follow a car and a wheel it bouncing over ever bump and continues to bounce. Not enough damping (or blow damper).

A damper does not control the body movement that is the job of the spring medium (as well as holding off the ground).

 

 

It's what Nick says. As much as most of us despise springs on a Mini and you really ought to invest in some proper rubber suspension, you need to understand what's happening and sort out what's wrong because you could run into a similar issue with suspension rubbers.

 

A damper is there to control the movement of the spring ... start by removing (or disconnecting) the dampers and see where it settles. this will be your ride height. Bounce up and down on the suspension and make sure it returns to the same point, if it doesn't you need to investigate further. When you're happy it's settling at the same point each time reconnect the dampers and set them on their softest setting. Bounce up and down again and if this time it doesn't return you're over damping the car and need softer shocks. Likewise if it settles okay initially but then droops after stiffening the shocks, you're over damping again, back 'em off.

 

The situation (and possibly your problem) will be compounded if you run soft(ish) springs with hard (over-damped) shocks - when you drive the car the additional driver weight and momentum weight as you drive over bumps will cause the spring & dampers to compress, but there won't be enough strength in the spring to overcome the shock and lift the suspension back to where it started, this is probably what you're experiencing.

 

And when you've sorted it ... bin the springs and fit some proper suspension :)



#15 tmsmini

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Posted 10 July 2019 - 09:06 PM

I have never seen yellow S Racer coil springs, only green, red and blue.

I have had S racer red springs on a car for a few years and never experienced the issue you are having.

Terry






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