What age and / or milage should shocks and springs be change

[Welshbeef]

As per title

Clearly shocks wear with milage and also age. Clearly you could choose to run them until one leaks then change that axle or until it is an MOT fail.
However shock absorbers are key to stopping distance. So again stopping distance to me is very high on the priority so guess what's the equivalent shock wear to tyres down to the 3mm tread depth at which point stopping distance increases materially.

Next springs.
These wear due to constant weight of the car compressing then so they lose their reverb clearly if you carry more weight more often they wear out sooner. Or if you drive on a rougher road surface they will wear out sooner.
Generally people change springs when they snap. And then change the whole axle or if they lower the car properly for track use or faster road driving.


So what's the views.

[v8will]

I've only changed something when it has been needed due to failure or in line with a planned upgrade. A new Eibach and Koni FSD setup with all new bushes and balljoints did wonders for the Volvo T5 project i had a few years back. It's the only time I've went that far with the suspension on a car and unless it was for something performance orientated, I doubt I'd treat a daily driver to pre-emptive work or upgraded suspension again. Outside of that I've only ever change 2 rear dampers on a Clio due to one failing and 2 rear springs on my old E36, due to one snapping.

Realistically most people will only change due to failure and refurbing suspension to give an 'as new' driving quality is an expensive operation - too expensive for most to care much about it.

[Welshbeef]

Should you also not change shocks all round not just one axle ditto springs else the handling will be very odd

[Ozzie Osmond]

Springs should not wear at all.

Shocks should last at leat 10 years if they were any good in first place.

Bushes fail first. Let's say from about 5 years. Spend your money here.

PS All of the above means nothing if you don't slow down for speed humps, which destroy thousands of cars every year.

[Welshbeef]

Springs corrode so their thickness decreases also fatigue they also sag

[1981linley]

Never if your vehicle has air suspension.

[Ozzie Osmond]

Welshbeef said:

Springs corrode so their thickness decreases also fatigue they also sag

Not in properly built cars less then 40 years old!

[Crafty_]

Note that springs snapping are quite common now, thanks to our crap roads and stiffly sprung heavy cars. Instant MOT failure.

Further to an earlier point I think its fine to change shocks/springs on just a single axle but you should never change just one corner on its own.

[OldSkoolRS]

I had a snapped spring on a Mk3 Escort many years ago (when they were only just starting to rust ). I had to replace the front struts on my RS2000 due to an MOT failure and it made such a difference to the way the car drove that I intend to also replace the rear shockers as part of recommisioning the car. Same goes for the various bushes as I've done a couple for MOT purposes when it was last on the road, but have the remaining parts already in stock so may as well fit them. FWIW the RS2000 is 1979 and the MOT fail was back in late 90s when it had maybe 57,000 miles on it. It's a pretty light car by modern standards, but maybe modern shocks last longer?

I'm also thinking about buying a full kit of bushes for my 'new' Z3, as these aren't massively expensive, but they have a hard life so I'm hoping it will sharpen things up a little; then maybe consider shocks/ coliovers, but this is more as an ongoing improvement process.

[300bhp/ton]

Welshbeef said:

As per title

Clearly shocks wear with milage

Nope I'd not say that at all. 10,000 miles on a smooth motorway would be far less taxing than 3000 miles on a cobble roads.

Welshbeef said:

and also age.

Nope not directly either, as you might only do 500 miles a year or 25,000 miles a year. On a 25-35 year old car maybe it's more of point, but nothing newish.

Welshbeef said:

Clearly you could choose to run them until one leaks then change that axle or until it is an MOT fail.
However shock absorbers are key to stopping distance. So again stopping distance to me is very high on the priority so guess what's the equivalent shock wear to tyres down to the 3mm tread depth at which point stopping distance increases materially.

Gas and oil shocks don't wear in the same way rubber tyres do.

Welshbeef said:

Next springs.
These wear due to constant weight of the car compressing

Maybe, but rust and high impact shock (pot holes) are likely far more damaging.

Welshbeef said:

then so they lose their reverb clearly if you carry more weight more often they wear out sooner. Or if you drive on a rougher road surface they will wear out sooner.
Generally people change springs when they snap. And then change the whole axle or if they lower the car properly for track use or faster road driving.


So what's the views.

Replace them as and when they need it, or you think they need it

[Condi]

Ive run 2 cars into the 200k+ mileage brackets and they have both been on original components. And this was in places where suspension takes a lot more abuse than it does in the UK.

It could be that over there they build them better than here, or it could be that suspension parts last longer than you seem to think. Either way, I would run it til it breaks and then change them. It would be very unlucky if, in 100,000 miles of motoring, your shock was to break and before you could make it home you had to do an emergency stop and push it so fine that the extra few yards made a difference as to crash or not crash.

[Welshbeef]

But changing them and also all the bushes will make such a difference to the handling it will turn a 80k car or whatever Ito a handling wise brand new car again.

[Adam205]

Modern dampers should be fine for a few hundred thousand miles before you see a serious drop off in performance. The oils used in them these days will hold their properties pretty much indefinitely as long as they don't overheat. Gone are the days of damper overhauls every 60k.

What causes them to degrade is dirt and water ingress causing the rod to corrode. If you're really worried, whip the dust covers off and give them a good clean once a year or so.

Springs shouldn't cause any issues as long as they look ok.

[Welshbeef]

Ok so given that is it vastly better to change all the bushes every 100k max to freshen things up

[OldSkoolRS]

Given some of the cheap non-OEM bushes that can be bought (particularly I'm thinking back to my old Sierra days and the motor factor's supplied anti roll bar bushes seemingly made of chocolate) some might need doing again well before that. My Z3 has 60K on it, but the history mentions a few bushes being replaced previous to my ownership, due to MOT advisories I think. Presumably they were the original BMW fit ones too. If they put cheap ones on then they may not last as long as the originals anyway, hence why I'm considering polybushes (the softer of the two types available so as not to totally destroy the ride).

[WeirdNeville]

Depends massively.

My current car has suspension that failed routinely, often within as little as 10,000 miles. Gues, what, it's gone again! Stupid design. I'm replacing the whole lot at 50k miles with new dampers and springs. Bushes are solid though and don't have a reputation of failing at less than 100k miles, if at all.

Other cars have lasted 100k miles + on original suspension (volvo V40 driven gently, Audi 8-, driven who knows how?)

BMW's eat lower front arm but they're easy and cheap to change and it's effectively a rebuilt suspension when you do it - both ball joints and a bush get refreshed, leaving just the damper and top mount (and track rod end I suppose)

I completely rebuilt the suspension on my 20 year old MR2, every bush, ball joint and damper replaced. It drove beautifully after that.

If you're pernickety and have the money, rebuild it. Really though, this stuff works until it breaks.

[steadvex]

gotta say, replaced the shocks on my now flood damaged 2005 s60 (very bitter!), made one hell of a difference to the handling of the car, everything improved, what shocked me the most was the braking, seemed like it brakes in a much shorterdistance and the whole car keeps level under harsh breaking wareas before it would dip heavily to the front...took a couple of weeks to get used to its handing again!

I changed them at aroun 160k (now gone at 168k!) took the car for a trip around europe, very glad I changed them before that

Sure theres no *need* to replace them, but if you really enjoy your car and enjoy looking after something i'd say go for it, personally i've done it on all the cars i've had for a while,

[Welshbeef]

I’m now going to get the rear springs changed on the Mrs SMax due to corrosion and an advisory on the last MOT.

So car 105k miles - should I switch the rear dampers at the same time or not worth it.

Note I’ll not be doing it myself so need to consider the labour to do the work.

[Chris32345]

Shocks Only need changing I'd they leak or casing gets very rusty
Also potentially if the bushes Go allthough you can get replacement bushes for some

[MDUBZ]

Nice thread resurrection ( at least it's tour own). I've had rear springs snap on an smax before, it hadn't covered half the mileage. I replaced both rear springs didnt think to check struts due to mileage tbh.

While you've got it up in the air you might as well check the struts to see what damping/ rebound they offer for peace of mind? Worst case youll need to cough up an extra £140 (inc top mounts). At that money I'd just be tempted to do it anyway.

I (garage) took some off a bmw with 70K as I was upgrading and lowering it a bit; the originals were fooked ( pushed the piston in with little resistance and it returned really slowly), visually there didnt seem much wrong with them. I have a mini JCW currently sat on the drive with less than 50K after the os front shock spewed its oil all over the place: you could feel the wheel was just bouncing in the arch. I figured I might as well upgrade all 4 corners (shocks and springs) as it gets driven quite hard at times.

Edited by MDUBZ on Sunday 26th July 19:30