I have a 2020 CX5 (purchased a year ago with 5400 miles). 80% of the miles I’ve put on are highway. I was told by my trusted mechanic that the rear shocks were leaking and needed replacing. I’ve never heard of shocks needing replacement so soon. Ideas?

 

Last year I was told I had 2 leaking shocks, one front & one back, and I would need to replace all four. I had 42,000m on the clock. Took it to another shop & they said no fault & showed me the UNLEAKING shocks. I then took it to another shop to get a 3rd assessment & they also said no fault.
I suggest that you go to another shop & get a second opinion.

 

Do you know what was done to the car during previous 5400 miles?
Anyway, all forum talk in that case is only speculation. Take it to another trusted mechanic for a second opinion. Any mechanical component is subject to premature failure (manufacturing defects), that's what a warranty is for.
Personally I think shocks must last much longer than 24000mi, if they are not abused.

 

My 2020 Frontier had a bad shock around 5k miles. Took it in and they found the shock had failed (leaking oil) and replaced it under warranty. No off-roading or rough treatment. Just a bad shock. I had two wheel bearings fail on a 2002 Porsche Boxster at under 10k miles as well.

 

*Thats because you don't work in auto service?

There could be numerous reasons why a damper leaks.
Driving on a Highway is not really an indicator of how long a dampener would live. I.e Nebraska roads are some of the worst currently in the nation and can and does cause frequent damage vehicles suspension parts.

My question is are they both leaking? Because that would be unusual with low miles? I would get clarity on that point from your service advisor. I will say however aside for a dealership under warranty it is very common for independent service shop to recommend replacing shock in pairs or per axle instead of a single unit. There are suggested technical reasons for this. I am one that dampers should be replaced per axle if one fails or is damaged.
Unless you have been caring frequent heavy weight in the rear section or towing a trailer that was not set up correctly and loaded.

You do not necessarily need to go to another service shop for the same recommendation. If the dampeners is leaking, you will be able to see it. It is a no brainer that it needs to be replaced.
Also previous service work would have no effect on a dampener to cause it to leak. So past service history in their case is also not necessary and may convolute the solving or better information to you.!

ASE

 

I'd get a second opinion, and try to look yourself with a light to see if they are actually leaking. I wouldn't expect shocks to go bad that fast, but they are a moving part that takes in a lot of force so it's not impossible for them to go out early. Considering your car is around 5 years since being built and put into use on the roads, it could be a case of time aging out the rubber and other materials.

 

Um I blew a rear shock in my 2018 in the first year.
There is a lot of actual engineering design internally in high presure gas shocks. So having one go out as soon as mentioned is not rare or out of the scope of reality.
The seals are actually rings and seal is the back up seal in high pressure dampeners

You would laugh if you read on forums how some even shops use OLD SCHOOL ways to determine if a dampeners is bad and most are replacing perfectly good dampeners.

 

Yah I wouldn't be surprised lmao.