Are lowering springs on stock shocks okay? Should you do it? Do you need to change the shocks if you change the springs?
(Assuming the lowering spring manufacturer says the specific springs are okay for stock shocks) The accepted answer is “if your dampers are in good condition you don’t need to change your stock shocks when you fit lowering springs”
And this has always been my advice. However I have changed the lowering springs on a car (from a 60mm lowering set to a 35mm lowering set ) and I had some issues later, namely two shocks blew out.
Maybe this was to do with the changing the springs, maybe not.
Bit of Background
The car was used like this for well over 100,000km. Zero issues (apart from those mentioned in the TEIN video).
Because of the issues mentioned in the TEIN video, we decided to swap them out for a set of H&R lowering springs which are only 35mm lower than stock.
Swapping from the TEIN lowering springs to the H&R raised the car by around 25mm.
What Happened Next – The Issues
After around 15,000km with the new H&R springs (and the original B8 dampers that were fitted with the TEIN) problems started to occur.
The first thing that happened was a front strut blew out. Completely. Oil all around the wheel arch. Completely shagged. But before it blew up it had started to knock.
So we swapped out the front B8s for a pair of KYB Excel-G shocks/dampers. This gave some material for the YouTube channel eg what is it like to mix sport dampers and stock dampers.
About 5,000km after fitting the new Excel-G dampers on the front, the rear right B8 damper also blew up ejecting oil over the rear suspension. This was a catastrophic failure which led to the damper giving zero damping. Again, completely shagged.
Was it a coincidence that a set of Bilstein B8 dampers which had been perfect for over 100,000km suddenly saw one front shock blow up and one rear shock blow up within 6 months of fitting springs with a different ride height?
It’s a possibility.
What do I think?
After so many KMs I expect the dampers wore out the shafts/seals/rods etc at a specific place.
Changing the ride height after so many KMs led to the damper/valves/seals working in a different part of the damper tube ie a part that was not so worn. And this led to the leakage issues.
Again, it could be a coincidence but I also think it could be down to the potential wear issues I just highlighted.
To answer the question
Can you use lowering springs on stock shocks?
Do you need to change your shocks when you fit lowering springs?
In this case, the suspension had epic KMs on it. If I was going to do it again I don’t think I would do anything differently. Because the dampers were so expensive and because I wasn’t going to sell them to anyone and because I wasn’t go to have them sitting on a shelf. I was always going to use them with the new springs, even if it destroyed the shocks.
However, if I had the stock shocks still on the car when I changed the lowering springs and if the dampers had over 50,000km on them, I think I would preemptively change the dampers at the same time as the lowering springs. Solely to eliminate the chance that I would have to pull the suspension apart again in the future to replace the dampers. The added bonus being I’d have a fresh set of dampers to go with my fresh set of springs.
If you are thinking of fitting lowering spring on stock shocks, hopefully this article helps you decide if you should swap out your stock shocks for a new set at the same time.
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