How often should I change my shocks? Yearly or how often and what type would you recommend?

 

I'm probably a minority here but I usually don't change them as long as they aren't leaking oil.

 

The reason why I ask, is that I had new ones (Bilstein) put on 5 years ago and I just rolled over 340,000 miles on the truck and I was just needing some advise.

 

It is good preventative maintenance but I'm cheap some times. When it starts leaking oil then replacement is no longer optional.

 

340K on the same set of shocks?..lol..yeah get new shocks. IMO most shocks are pretty worn by 50K. Might not be leaking but they definitely wear out and lose performance.

 

I have at least 200,000 miles on these. I have 340,000 total on the truck. I had to have the motor remanufactured late last year. I have at least 5-6 more years with the truck. I do love it, but I do a lot of highway driving with it.

 

The “professionals “ say 50-100,000 miles. But imo the style of driver, the road conditions and how the suspension is worked makes a difference.
i had a service trucks that required new shocks every 40,000 miles. But mileage on a lot of rough roads, had a lot of weight in it. My daily driver 2003 Crown Vic with 160,000 miles is still on original shocks. There is absolutely no uneven tire wear or any indication of a blown shock. No leaks and the suspension is good. But it gets driven on clean smooth freeways .
my wife’s 2004 QX56 didn’t get new shocks until about 175,000 miles. The front factory shocks finally started leaking. Replaced with Bilstein.

if they are pitted on the piston rod or leaking oil or show some tire wear from work shocks then replace them.

 

thats why they aren’t wearing fast. Pull one shock off and try to press it down. If it’s blown it will collapse in itself.

 

I’m just trying to provide some clarity on when/why shocks should be replaced - not addressing any one post in particular.

To be clear, I’m only talking about shocks - not a strut, which is a coil spring and shock assembly - however the points I’m going to make do also apply to the shock absorber components of a strut.

FYI for anyone that doesn’t know - the term “jounce” refers to the up and down movement of the suspension as it moves with changes in the road.

1) The recommendation to replace them at 50,000 miles is because studies have shown that, by the time the average vehicle has reached that many miles, a shock has completed approximately 3 million jounce cycles. For practical reasons the shock is considered worn at that point.

2) Even the smoothest road surfaces aren’t smooth enough to prevent suspension jouncing, especially at highway speeds. If you don’t believe that, wedge a steel rod between the axle and frame and drive the smoothest road you can find - I’m betting it’s not as smooth as it looks.

That’s not to say that they can’t wear out faster on gravel vs. pavement, but overall, the road surface isn’t the primary factor.

4) Shocks assist in stopping and turning safely. Just because a shock isn’t leaking doesn’t mean it’s doing it’s job, and in an emergency situation, worn shocks can be the difference between safely avoiding a collision or becoming part of it.

Of course there are always exceptions and it really depends on the individual driver, but IMO it doesn’t make sense to not replace shocks if there’s any question as to their condition. The relative cost of shock replacement vs. vehicle replacement and medical bills is minor.

2 quick tests to determine shock condition:

1) Using your body weight, jounce a corner of the vehicle 4-5 times and release - the vehicle should stop moving within 1-3 jounce cycles.

2) At slow speeds, and with no one behind you, press and release the brake pedal several times with moderate pressure so the vehicle is rocking in a see saw type motion. The vehicle should stabilize within 1-3 jounce cycles.

 

This is pretty good info, except you have some of your terminology wrong. Jounce refers to the bounce or vertical movement of the vehicle suspension upward when it contacts a bump in the road. AKA:compression. Rebound refers to the downward movement of the vehicle suspension in the opposite direction of jounce. AKA extension.

http://144.162.92.233/faculty/djones...suspension.pdf

Quality/Higher end shocks are more likely to be "tuned" to a specific vehicles jounce/rebound characteristics vs. cheaper shocks that have one valving they use across a large line of vehicles. Some manufacture use to list the same shock PN for a RCSB F150 all the way up to CC/LB F350. Hows one shock gonna work well on a 4000lb truck and also a 7000lb truck?

 

thats why I always laugh at the base line shocks. What kind of shock are you getting for 30 bucks? And they habe a rebate for $5. I guess if you’re dumping the truck or are barely scraping by you can say hey it’s got new shocks.

I tend to buy Bilsteins if they are made for the vehicle I drive. Yeah they are a bit expensive but they last a long time. I mean a person could buy cheaper shocks and have them mounted but doing two shocks sets in the same or less amount of time that a expensive set lasts well you’re paying for labor twice. And labor isn’t cheap. If you diy sure you got a cheaper price and “saved money” but what’s your tie worth. Crappy shocks are crappy shocks regardless.

 

Regarding the terminology - I know there’s technically a difference between jounce and rebound, but for the purposes of discussion, I consider jounce or jounce cycle a good enough term.

During normal driving, jounce and rebound happen consistently. If the suspension jounces, it will rebound before it returns to the at-rest position; and vice-versa.

It also saves the trouble of typing out multiple terms when it’s not necessary for these giant, clumsy fingers.

Regarding differences between replacement shocks, I don’t know anything for certain, but I’ve often suspected that as long as the part bolts in place, it’s considered correct for the application. But that’s just speculation on my part.

 

I've been in and around the auto repair/parts world for close to 30 years, that's not always the case with suspension parts. Cheaper parts are sometimes made with non-OEM spec materials or designs that technically work, but not the way the original manufacture designed it. So a cheaper part manufacturer might make a single PN shock, or a spring, or maybe a bushing, that might fit 20 different applications, where the OEM might have 5 different PN's for those applications because they spec'd slightly different valving, or spring rates or bushing rubber stiffness depending on the application to get the best ride and least amount of vibration transfer through the chassis. The aftermarket parts will have to be built to handle the heavier vehicles the single PN covers, so it can end up being too stiff on the lighter vehicles that it covers. The difference between a suspension with parts that work and one with parts that were designed to work together is night and day.

 

In my experience the price and brand really dictates quality. Anytime you’re looking at buying the Amazon or EBay special deal of the day consisting of ..:.a set of 4 shocks for $100 made by Zebtec with a lifetime warranty and the business/customer phone number starts with a country code in some far away land….you’re guaranteed to buy absolute junk and never be able to get a warranty repair.

I remember some fat guy selling brake pads once saying “hey want me to take a dump in a box and guarantee it I can do that. “

. Not only is a lot of stuff junk but these discount white box parts have no quality control and can fail at the exact wrong time. And can cause more damage than they fix. Might as well throw $100 on the ground or set it on fire.
there are enough online retailers and manufacturers that sell quality aftermarket parts and plenty of online car dealers that sell factory parts at good discounts . Yeah you’re not getting 4 shocks for $100 but do you really want to?
last thing I want is to be 1500 miles away with a broken truck because that $20 sensor or $90 hard part I was so happy I got with a Group-on code failed and the tow truck driver doesn’t care if I give him a bad Yelp review.