8880 weak springs

[Amt0571]

A couple of years ago I rebuilt my 8880 Supercar from when I was a kid to show it on a shelf in my office. The car has been "lifted" from the shelf using a stand (the wheels were not touching the ground, and the springs were as extended as the suspension arms allow). The car worked perfectly after the rebuild.

I had barely touched it until today, and to my surprise I found that the suspension springs are barely able to return. If I push the car down it returns really slowly or doesn't return at all. I found it surprising because when I built it I felt that the suspension was way too hard, and I also remember this feeling from when I built it when I was a kid.

I have always disliked the fact that with the suspension fully extended the springs are still partially compressed, and I'm not sure if this could be the cause of the "damage". Is this a possibility? I'm thinking about displaying it with the shocks lower pivots removed, so as the shocks are fully extended, and see if they recover... is that possible? or once they get weak there's no turning back?

It's not a huge issue, since it's now a shelf queen, but it bothers me somewhat to have it not working as intended.

Edited January 27 by Amt0571

[allanp]

That is strange. I also remember thinking the suspension was very hard. Did you use the springs that came with the 8880, the dark grey ones, as they are stiffer than the black ones. You can try disassembling the spring assembly and physically stretching the springs back out. 

 

[Stereo]

I think it's more likely the parts are dirty and don't slide smoothly enough (probably the spring itself but maybe other suspension parts, along with usual caveats about not clamping moving parts too tightly between bushes).  That style of spring puts a pretty big side-load on the sliders (since the top end axle hole is offset from the spring)  A few years ago I rebuilt my 8448 and cleaned/dusted everything and the steering and drivetrain worked way more smoothly.  I've had it on its wheels on a shelf for its entire 25+ year life and the springs haven't lost anything, just sitting shouldn't affect them.

 

Track width also changes quite a bit on compression cause the control arms flatten out, so tire grip on the ground prevents suspension from returning smoothly.  If it's that, you could try putting one side's tires on sheets of wax paper on carpet, so they can slide sideways, see if that helps.

Edited January 27 by Stereo

[Amt0571]

6 hours ago, Amt0571 said:

2 hours ago, allanp said:

That is strange. I also remember thinking the suspension was very hard. Did you use the springs that came with the 8880, the dark grey ones, as they are stiffer than the black ones. You can try disassembling the spring assembly and physically stretching the springs back out. 

 

They're the grey original ones. I have disassembled one and it extends to the original length, but it's definitely weaker than it was.

 

1 hour ago, Stereo said:

I think it's more likely the parts are dirty and don't slide smoothly enough (probably the spring itself but maybe other suspension parts, along with usual caveats about not clamping moving parts too tightly between bushes).  That style of spring puts a pretty big side-load on the sliders (since the top end axle hole is offset from the spring)  A few years ago I rebuilt my 8448 and cleaned/dusted everything and the steering and drivetrain worked way more smoothly.  I've had it on its wheels on a shelf for its entire 25+ year life and the springs haven't lost anything, just sitting shouldn't affect them.

 

Track width also changes quite a bit on compression cause the control arms flatten out, so tire grip on the ground prevents suspension from returning smoothly.  If it's that, you could try putting one side's tires on sheets of wax paper on carpet, so they can slide sideways, see if that helps.

I've disassembled one of them and they're clean. They feel definitely weaker than I remember them.

[JesseNight]

If the metal spring itself got weaker when trying it in disassembled state, then it's probably metal fatigue. I don't know the quality of Lego springs but it's not exactly uncommon on 30 years old springs.
Wouldn't be surprised if there's third party replacement springs available somewhere that would fit.

I'll give my own 8880 a quick check later, I do remember the suspension being quite hard on this car. My childhood friend used to show off dropping the red 8865 Test Car (the model before) with the light gray old model springs, and it would be fine. I remember doing that with my 8880 and the hard springs just making parts fly off that the springs were connected to.

[edit] Yeah my own have definitely gone weaker too. Not weird on a 31 year old spring though.

Edited January 27 by JesseNight

[Amt0571]

47 minutes ago, JesseNight said:

If the metal spring itself got weaker when trying it in disassembled state, then it's probably metal fatigue. I don't know the quality of Lego springs but it's not exactly uncommon on 30 years old springs.
Wouldn't be surprised if there's third party replacement springs available somewhere that would fit.

I'll give my own 8880 a quick check later, I do remember the suspension being quite hard on this car. My childhood friend used to show off dropping the red 8865 Test Car (the model before) with the light gray old model springs, and it would be fine. I remember doing that with my 8880 and the hard springs just making parts fly off that the springs were connected to.

[edit] Yeah my own have definitely gone weaker too. Not weird on a 31 year old spring though.

The thing is that a couple of years ago, when I rebuilt the car, the springs felt ok. I think that they got weaker because they're partly compressed when in the car even when there's no weight on the wheels.

I previously had built the car twice when I was a kid, but it had never been assembled for more than a week or two.

[JesseNight]

22 hours ago, Amt0571 said:

The thing is that a couple of years ago, when I rebuilt the car, the springs felt ok. I think that they got weaker because they're partly compressed when in the car even when there's no weight on the wheels.

I previously had built the car twice when I was a kid, but it had never been assembled for more than a week or two.

That does make a difference in wear yes. Storing springs without any tension on them prevents metal fatigue.
I'm actually surprised mine still work fairly okay even if a bit softer, considering for 31 years the car hasn't been disassembled for more than 2 years that I remember.

Edited January 28 by JesseNight