Should I replace 2 shocks?

JaCrispy

Hi,

I've an 11 ix35 (85k miles) - dropped it in for a service last week and the guy said one of the rear shocks is leaking.
He said that really I should be changing both the shocks. That would cost 400euro instead of my budgeted 200euro.

Is he blackballing me? Should I be changing boths shocks even though only one is faulty?

5W30

Yes you should change both shocks.

When they test your car at the NCT they look at the imbalance between both sides of the car. If one shock is used and one is new there will be imbalance even though the shocks are good and your car will fail.

magentis

Shocks should be replaced in pairs ideally.You could end up with an nct failing imbalance otherwise.€400 sounds a bit ott for 2 shocks though.

*Kol*

5W30 wrote: »

Yes you should change both shocks.

When they test your car at the NCT they look at the imbalance between both sides of the car. If one shock is used and one is new there will be imbalance even though the shocks are good and your car will fail.

That's not always the case. If the shock you are replacing is still in good condition then the imbalance will not be above the fail limit. A new shock wont score 100% in the test anyway. I speak from recent experience of this. The new shock basically scored the same as the one I left in at the retest.

colm_mcm

Price around. I know you're still within warranty but getting them done outside the Hyundai dealer should be a bit cheaper.

BrianD3

5W30 wrote: »

Yes you should change both shocks.

When they test your car at the NCT they look at the imbalance between both sides of the car. If one shock is used and one is new there will be imbalance even though the shocks are good and your car will fail.

Two threads that show that this isn't the case

http://www.boards.ie/vbulletin/showthread.php?t=2055376733
http://www.boards.ie/vbulletin/showthread.php?p=58450596


-I pass the NCT with 0% imbalance with 20k miles on one front shock and 190k miles on the other
-another poster passes the NCT with an 11% imbalance with 0k miles on one rear shock and 100k miles on the other.

In the OPs case, if one shock is leaking and the other shows no evidence of leaking or damage and especially if the leaking one is on the nearside - the OP should replace the leaking shock only.

CiniO

JaCrispy wrote: »

Hi,

I've an 11 ix35 (85k miles) - dropped it in for a service last week and the guy said one of the rear shocks is leaking.
He said that really I should be changing both the shocks. That would cost 400euro instead of my budgeted 200euro.

Is he blackballing me? Should I be changing boths shocks even though only one is faulty?

Yes, you should change both shocks.
No, you shouldn't pay such mad price for that.

5W30

BrianD3 wrote: »

Two threads that show that this isn't the case

http://www.boards.ie/vbulletin/showthread.php?t=2055376733
http://www.boards.ie/vbulletin/showthread.php?p=58450596


-I pass the NCT with 0% imbalance with 20k miles on one front shock and 190k miles on the other
-another poster passes the NCT with an 11% imbalance with 0k miles on one rear shock and 100k miles on the other.

In the OPs case, if one shock is leaking and the other shows no evidence of leaking or damage and especially if the leaking one is on the nearside - the OP should replace the leaking shock only.

Is it worth an NCT retest fee and bringing the car to a mechanic again AND having to replace the other side when it fails ending up having oddly wearing shocks?

This is the reason why this country is filled with cars that are lemons. Don't break simple rules of automotive repair. Do it in pairs.

*Kol*

If only one is leaking yes. The imbalance is because of the one leaking shock. Once the imbalance is large you will be able to replace only one shock. If a shock is not leaking it will operate normally.

corkgsxr

Id always do pairs. If one is worse it will wear the better faster.

Or you have unpredictable handling.

60 on a left turn fine, 60 on a right and your nearly over a ditch

Duke O Smiley

colm_mcm wrote: »

Price around. I know you're still within warranty but getting them done outside the Hyundai dealer should be a bit cheaper.

Will that invalidate the warranty?

JaCrispy

An update. Just changed the 1 shock and sailed through the NCT yesterday.

clogher71

It should be under (5 year) warranty....why call into a dealer?

JaCrispy

Ive gone over 100k miles

martinr5232

LIGHTNING wrote:

Congrats your car now has a unbalanced setup but sure you passed the NCT so whatever right

How is it unbalanced ?? It passed the nct so its obviously within specification.

rex-x

The NCT specifications are extremely "loose" bare minimum for safety

joujoujou

rex-x wrote: »

The NCT specifications are extremely "loose" bare minimum for safety

+1.

Passed NCT 2 or 3 years ago with one of the coil springs broken - all readings within limits.

Guy:Incognito

martinr5232 wrote: »

How is it unbalanced ?? It passed the nct so its obviously within specification.

If its 1% under the limit it will pass. Hitting a pothole on the way home from the ncr could send it above the limit and it'll most likely not be checked again for 2 years, by which point it could be rally bad.

JaCrispy

LIGHTNING wrote: »

Congrats your car now has a unbalanced setup but sure you passed the NCT so whatever right :pac:

I didn't post the results so how do you know it has an unbalanced setup?

5W30

Out of interest did you replace the shock yourself or was it a garage? I'd rather not visit the garage if it was done by one if they really only changed 1 shock :pac:

martinr5232

Guy:Incognito wrote:

If its 1% under the limit it will pass. Hitting a pothole on the way home from the ncr could send it above the limit and it'll most likely not be checked again for 2 years, by which point it could be rally bad.

That could happen if you replace both shocks.

Ideally shocks should be replaced as a pair but not everyone has four or five hundred euro to replace them in pairs.

JaCrispy

LIGHTNING wrote: »

New shock one side + old shock other side

That doesn't automatically mean it is unbalanced.

colm_mcm

JaCrispy wrote: »

Ive gone over 100k miles

It's unlimited mileage on Hyundai's isn't it?

Shocks are wear and tear anyway.

5W30

LIGHTNING wrote: »

Of course it does! Do you think shocks have an infinite lifespan? Shocks/Springs all suspension components have a shelf life. They wear out,tolerences loosen, sag etc. There is a reason car companies spend millions a year on suspension setup/design! They specifically say to replace them in pair for this reason. You have pretty much altered the setup of your car.

But then again I saw another thread in here where a user complained about wheel spin in the wet and they had some of the cheapest tyres around. Gotta love this country where we spend as little as possible on car maintenance.

Not only that but the replacement spurious shock probably has a different spring/rebound rate compared to the original shock

bazz26

From my previous experience of trying to be penny wise and end up being pound foolish by only replacing one shock, the imbalance resulted in the other one to weaken further and I ended up having to make another trip to the mechanic to have that one replaced about a month later too. Lesson learned to replace both at the same time.

mickdw

It is also possible that after another 2 years wear and tear, the old shock might have developed a similar fault or deteriorated and results in a failed test again. You then have to fit the shock anyway and then you still end up with a slight imbalance again due to different ages of the shocks.
It just doesn't make sense installing them in ones.
Now for your ordinary careful driver this slight imbalance will never likely be noticed but that doesn't make it right and just cause it passed the test doesn't mean it's to a factory fresh standard either.