Rebuilding Shocks
#1
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Many of you have expressed interest in what happens to shocks when service is neglected as well as to what to look for as a tell tale for bad shocks...
'First and foremost this set of dampers had no outside visual leaks or damage. And it held pressure in the canister of 250psi. Usually thats only when they show up is when they are leaking
So visually the damper was good.... and the shaft went down and came back up! thats what its supposed to do right? until you get it on a dyno
This shock set was 3 years on a car and was never rebuilt.... The following is what happens.
They pic of the dyno just shows what looks like a fat line.... That is all of the clicks in the compression range high and low speed.... So basically you could add compression, but the shock didn't respond any differently!
The pics that follow are of the guide, which surrounds the piston at the top of the shock body and locates it in the center.... as you can see instead of a shiny smooth bearing it has worn away, much like the cylinder walls of a engine if the oil is never changed. So that needs replacing.... This will be the only part of the shock that gets replaced, the rest is just cleaning and seals and fresh oil
The rest of the pics show how dirty the shock is internally. The shims are gummed up, the seals are not holding hydraulic pressure, and the oil is burnt and dirty.... These Dampers can get in excess of 300 degrees and some as high as 450.... so Imagine what happens to the oil when its not changed.... it breaks down and loses its viscosity and creates moisture (just like brake fluid).
'First and foremost this set of dampers had no outside visual leaks or damage. And it held pressure in the canister of 250psi. Usually thats only when they show up is when they are leaking
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
They pic of the dyno just shows what looks like a fat line.... That is all of the clicks in the compression range high and low speed.... So basically you could add compression, but the shock didn't respond any differently!
The pics that follow are of the guide, which surrounds the piston at the top of the shock body and locates it in the center.... as you can see instead of a shiny smooth bearing it has worn away, much like the cylinder walls of a engine if the oil is never changed. So that needs replacing.... This will be the only part of the shock that gets replaced, the rest is just cleaning and seals and fresh oil
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
The rest of the pics show how dirty the shock is internally. The shims are gummed up, the seals are not holding hydraulic pressure, and the oil is burnt and dirty.... These Dampers can get in excess of 300 degrees and some as high as 450.... so Imagine what happens to the oil when its not changed.... it breaks down and loses its viscosity and creates moisture (just like brake fluid).
#2
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Here we are all cleaned up, assembled, and ready to go back together with new o-rings, teflon's, and oil....
Here is a screenshot of the rebuilt shock on the dyne..... Its amazing what fresh fluid and seals does...... every click works just like it should.... with good range of adjustability.....
Once again outwardly the damper was fine! I like to tell people its like your eyes going bad, but gradually over time, the more you drive it the more you get used to the degeneration of the damper, then you try new glasses and you can see all of as sudden
Here is a screenshot of the rebuilt shock on the dyne..... Its amazing what fresh fluid and seals does...... every click works just like it should.... with good range of adjustability.....
Once again outwardly the damper was fine! I like to tell people its like your eyes going bad, but gradually over time, the more you drive it the more you get used to the degeneration of the damper, then you try new glasses and you can see all of as sudden
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
#5
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@ Francois This is just the cliff notes and there is so much more involved.... but preventative maintenance on shocks is something that few ever do!
Ha so I will see your doubles in a year!
Ha so I will see your doubles in a year!
#6
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@ Matt yes these are JRZ 997cup Motorsport Triples. The rear is the graphs and the fronts are getting the 1231 upgrade that we talked about before.
Thats what the dampers came in for was a upgrade to the 1231 valving..... not for a rebuild "car feels fine so no need for a rebuild".........
Thats what the dampers came in for was a upgrade to the 1231 valving..... not for a rebuild "car feels fine so no need for a rebuild".........
#7
Nordschleife Master