How to know if shocks are "Weak"?

[Jehu]

I had new tires put on tonight and the guy said from looking at the old ones my Struts might be weak. Bilstein Sports with a very rough aproximate 85,000 miles on them... is this even a possibility already? basically just a year and a half old... How can one test ? I read on the Sachs web site there is a device or machine but if I can't find a place that has one can you tell any other way ? Like before I ruin this new set of tires?

[632 Regal]

good question... I know how to tell is 1 side is worse than the other but to test both no clue. For the 1 side test there is a pretty good dip on a local freeway that I drive on every week. When my Bilshit blew the car would definitely not react evenly through out the dip. New shocks and stable as can be.

[Jehu]

What brand did you go with for new?

[Tiger]

You have someone take pictures while you are driving... Turn flash off and take picture while you are on highway... if picture always blurry, shocks are bad.

Easier way is this... if you have Boge, Sach, OE, even Bilstein Touring etc... 60,000 miles. If you got Bilstein Monotube or Koni, never need changing unless leaking.

[Tiger]

Bilstein Yellow!

[Jehu]

My Billies are Yellow and are the so called "Sport" variety... where do these come in in your hierarchy?

[shogun]

I am a member of the automobile club here and they offer to members free of charge shock testing. They drive around throughout the country in big trucks with these testing machines on the trailer. Don't you have that?
http://www.zf.com/brands/content/en/boge/technical_service_boge/shock_absorber_testing_boge/shock_absorber_testing_BOGE.html

[shadowpuck]

i've always wondered this myself...

i've pretty much operated on the "how does the car feel," and then combined that with how old the shocks/struts are, etc....

it'd be nice to know if there's a real way to test these.

no, shogun - i've never heard of anyone offering anything like that in this part of the world....perhaps a new business venture for you? :)

[Jehu]

I am a member of the automobile club here and they offer to members free of charge shock testing. They drive around throughout the country in big trucks with these testing machines on the trailer. Don't you have that?
http://www.zf.com/brands/content/en/boge/technical_service_boge/shock_absorber_testing_boge/shock_absorber_testing_BOGE.html


Search returns no results in my region... How backward are we,lol... Is a year and a half /80k miles of long distance, high speed driving a reasonable lifespan . I assume such a thing can not be determined absolutely . Does it seem early to require replacment if not otherwise subjected to severe abuse from regular use on rough road surfaces?I have driven on my fair share of very heavily pitted dirt roads and hit some pits at highway speed . Perhaps such hard impacts can rapidly dimish the useful life of the part....

[bad_manners_god]

Do the bounce test. Push down on each corner of the car the same amount (e.x: 2 downward pushes) and measure how long it takes for them to come back to their original position. If they all have the same amount of time, it can only mean 1 of 2 things.

A.) All the shocks are good
B.) All the shocks are bad

The longer they take, the closer they are to need to be changed.

[Washburn]

"The longer they take, the closer they are to need to be changed."

I would dis-agree with this. If it takes longer for the car to return to normal ride height, the shock are doing their job. (Rebound damping) If the car comes right up quickly, or bounces a little, the shocks are not doing their job, which is to dampen. Less dampening = faster spring rate movement. The "sportier" the shock, the longer it should take to rebound. Drive over a speed bump slowly....does the car bounce at all? If so, your probably ready.

[Tiger]

This doesn't work on most car anymore.

[Tiger]

The King... These really never need to be changed unless they are leaking. Bilstein did a test on their monotube... after 100000 miles regular driving, the took them out and test their performance... They got 95% of the performance as their new one.

[glen-sj]

You have someone take pictures while you are driving... Turn flash off and take picture while you are on highway... if picture always blurry, shocks are bad.

Easier way is this... if you have Boge, Sach, OE, even Bilstein Touring etc... 60,000 miles. If you got Bilstein Monotube or Koni, never need changing unless leaking.

How do the Bilstein Monotube compare to the Bilstein HD or Sport? Is the Bilstein Monotube stiffer on the ride? I'm getting ready to replace the OEM stock struts and shocks on the 95 530.

[bad_manners_god]

"The longer they take, the closer they are to need to be changed."

I would dis-agree with this. If it takes longer for the car to return to normal ride height, the shock are doing their job. (Rebound damping) If the car comes right up quickly, or bounces a little, the shocks are not doing their job, which is to dampen. Less dampening = faster spring rate movement. The "sportier" the shock, the longer it should take to rebound. Drive over a speed bump slowly....does the car bounce at all? If so, your probably ready.

Actually, it's the opposite of everything you said. To prove: I work as a mechanic and have replaced about 60 shocks. When the shocks are finished, they can be pushed down with very little effort (with no spring)

Therefore the car will bounce more because the spring is what is controlling the amount of bounce.

When the shocks are new, they are extremely difficult to push down by hand (with no spring) and return to their full extenstion right away.

Therefore, the car will bounce less because the shock want's to always return to it's full extenstion where-as the spring can go either way with no control.

[632 Regal]

went with Boge/Sachs turbo and the handling in my opinion is much better than the prior. Also get no bottoming, dont need to cut internal bump stops, dont need to be out of a vehicle when I send the Billies in for them to say they are out of warrantee etc. I like the new choice.


What brand did you go with for new?

[bmwrp8]

went with Boge/Sachs turbo and the handling in my opinion is much better than the prior. Also get no bottoming, dont need to cut internal bump stops, dont need to be out of a vehicle when I send the Billies in for them to say they are out of warrantee etc. I like the new choice.

why did they said it was out of warranty? thought it was lifetime?

[Washburn]

Actually, it's the opposite of everything you said. To prove: I work as a mechanic and have replaced about 60 shocks. When the shocks are finished, they can be pushed down with very little effort (with no spring)

Therefore the car will bounce more because the spring is what is controlling the amount of bounce.

When the shocks are new, they are extremely difficult to push down by hand (with no spring) and return to their full extenstion right away.

Therefore, the car will bounce less because the shock want's to always return to it's full extenstion where-as the spring can go either way with no control.

I think we may be talking two different things. Your talking about an un-installed shock that you are pushing down on, and then looking at the time it takes to return to full extension on it's own. This is a result of the gas charge, and has little to do with the actual damping rates in both compression and rebound. As proof, we racers routinely de-gas our shock....let out all the gas pressure...so they no longer return to full extension on their own. Letting the gas pressure out does not change the damping rates. Thats a function of wear on the internals that control the fluid flow. For a mechanic as yourself, your test is a good one because it usually indicates that a standard "street" shock is near the end, but the reduction of gas pressure alone does not necessarily affect the damping rates.

While a gas pressurized shock will contribute some to the time a car takes to return to normal driving height, it's fairly small. The springs are doing all (most) the work, the pressure in the shock doesn't do a whole lot, maybe a little. (You will feel it a lot uninstalled and pushing with your hands, but it's much less when you consider the weight of the car on it.) The shock's job...especially on a performance shock...is to *slow* that rate of return, not contrubute to it. (Damping) The slower the spring forces the car body back up, the more rebound damping you have in the shock. A car returning to original ride height quickly can indicate that the internals are worn out and there is less rebound damping. (Rebound damping is what most people feel when they say their shocks are worn) Being able to push down on a car quickly, and have it return back up quickly usually means there will be bounce which means the shocks are not damping the springs movements. (Pretty much what you said, but in a different way.)

This is a good conversation and we're both right in certain ways. Hope I'm not being a smart ass, but setting up and tuning race cars, and having opened up and re-valved shocks myself, has given me a little insight in the never ending mysteries of shocks. All I know is my Touring is bouncing all over and I need shocks!!

[Jehu]

I think I narrowed a chuncking noise in my right rear to a shock mount and Opinions sought at a local Tire shop's ex- Bimmer Indy shop guy was that my Billies are done. He drove it with me in the passenger seat. He owns an E32 now and said he's owned three e34s... i was satsified..... till he gave me a quote of over $2k to replace them,lol.. I think I paid about $1,100.00 parts and labour last time elsewhere.

But he did say the HD were the reccoemended of the Bilsteins for this car... Opinions?

[Tiger]

Do it yourself! It is not so hard for the back... the front one is the harder one to do. If you got lowering spring, you need Sport... Sport is HD with shorter rod.

If your rear shock mount is bad, how can you tell if your shock is bad? You can't.

[Jehu]

Do it yourself! It is not so hard for the back... the front one is the harder one to do. If you got lowering spring, you need Sport... Sport is HD with shorter rod.

If your rear shock mount is bad, how can you tell if your shock is bad? You can't.


Well i was going on this other dude's experience owning three e 34s and being a "Tuner" by trade and his claim that the miles I have on them i should replace them anyway. It is WINTER here.. I have no GARAGE available for my use so I must PAY another even if he allows me to HELP do it ... No professional garage will allow me to do the whole job myself,taking up his work bay without compensation and i wouldn't expect it anyway so i'll have to pay and at that point its worth it to pay to have all of it done.

Is there any difficulty replacing the rear strut mounts? Are there heavy duty mounts available? I think i saw one by Ruff?

[Tiger]

You just need a spring compressor to do the job. Once you drop it down, all you need is spring compressor to relieve it from the mount. Once you drop it down, you can take it inside and do the job. Yeah it is winter here too

I feel this guy is ripping you off major time. You will see once the spring is removed... the shock is still good. Heck, if it is bad, Bilstein will repair it or send you another one provided you have the receipt.

OE is the only one I know that is good... the Meyle is POS... Bioge is spoosedly OEM.

[Jehu]

You just need a spring compressor to do the job. Once you drop it down, all you need is spring compressor to relieve it from the mount. Once you drop it down, you can take it inside and do the job. Yeah it is winter here too

I feel this guy is ripping you off major time. You will see once the spring is removed... the shock is still good. Heck, if it is bad, Bilstein will repair it or send you another one provided you have the receipt.

OE is the only one I know that is good... the Meyle is POS... Bioge is spoosedly OEM.


Well I wasn't planning on having the $2K quote shop do it but ...


in fact I found the old installation receipt and it cost me $275.00 for 4.5 hrs @$60.00/hr and the shocks were around $460.00 for the parts..

I didn't realize Bilstein offered a lifetime warranty ... yet now I see what was mentioned before about doing without your car till you get your replacements. This is my only car so i'd incur an additonal cost for alternate transporation but I did buy these parts at Bavarian Auto who is a ncie one hour drive East of me so I'll call thyem and see what they have to say about this .. maybe they'll jst ship me a new set .....

[bad_manners_god]

I think we may be talking two different things. Your talking about an un-installed shock that you are pushing down on, and then looking at the time it takes to return to full extension on it's own. This is a result of the gas charge, and has little to do with the actual damping rates in both compression and rebound. As proof, we racers routinely de-gas our shock....let out all the gas pressure...so they no longer return to full extension on their own. Letting the gas pressure out does not change the damping rates. Thats a function of wear on the internals that control the fluid flow. For a mechanic as yourself, your test is a good one because it usually indicates that a standard "street" shock is near the end, but the reduction of gas pressure alone does not necessarily affect the damping rates.

While a gas pressurized shock will contribute some to the time a car takes to return to normal driving height, it's fairly small. The springs are doing all (most) the work, the pressure in the shock doesn't do a whole lot, maybe a little. (You will feel it a lot uninstalled and pushing with your hands, but it's much less when you consider the weight of the car on it.) The shock's job...especially on a performance shock...is to *slow* that rate of return, not contrubute to it. (Damping) The slower the spring forces the car body back up, the more rebound damping you have in the shock. A car returning to original ride height quickly can indicate that the internals are worn out and there is less rebound damping. (Rebound damping is what most people feel when they say their shocks are worn) Being able to push down on a car quickly, and have it return back up quickly usually means there will be bounce which means the shocks are not damping the springs movements. (Pretty much what you said, but in a different way.)

This is a good conversation and we're both right in certain ways. Hope I'm not being a smart ass, but setting up and tuning race cars, and having opened up and re-valved shocks myself, has given me a little insight in the never ending mysteries of shocks. All I know is my Touring is bouncing all over and I need shocks!!

I agree in a way, we do both make good points. What I really meant by the "bounce test" was if the car keeps bouncing without damping then the shocks are finished.

A couple months ago we had a 96 Dodge Caravan that was going for scrap and the shocks were a few months old, monroe sensatrac's. So we uninstalled them before we sent the van out. On the way out of the shop, my boss hit the brakes and the van wouldn't stop bouncing, looked like one of those rides you put your kids on at the mall.

[Tiger]

Driving a car without shocks?! Very funny and dumb.

[632 Regal]

As long as you supply the old ones, Bilsteins have the worst warranty system here. if you need the car within 2-3 months you are screwed. Everything has to be shipped to germany and then tested. if you dont mind that then it is good. I like my Sachs.


maybe they'll jst ship me a new set .....

[Jehu]

As long as you supply the old ones, Bilsteins have the worst warranty system here. if you need the car within 2-3 months you are screwed. Everything has to be shipped to germany and then tested. if you dont mind that then it is good. I like my Sachs.


LOL... LOL..... bwaahaa.. I'll just get the guy who did it before to pop some in sometime.. You sure the Sachs aren't squishy/boring/? Those Billies were hella firm for a while..

[Tiger]

Tell your guy to save the old one so you can send them in for warranty. Hey! It's free! and you will always have another set to go...

[e34.535i.sport]

I recently changed my front shocks because the front passenger side was seriously worn... It would shake the car violently when hitting a bump or pothole. Luckily the new shocks sorted this right out!!!! If I done the 'bounce' test on it with the worn shock I found it would take about 3 or 4 bounces to return to it's normal position. Now, with the new shocks installed doing the bounce results in the car settling right back to it's normal position immediately without any bouncing (and they are performing perfectly on the road).

This leads me to believe that the less bouncing the better...

[Jehu]

Tell your guy to save the old one so you can send them in for warranty. Hey! It's free! and you will always have another set to go...


I came to that realization myself yesterday.. its a win win,lol..

in spite of Regals persuasivness I still think I like the extra firmness of the Bilsteins... talk me out of it..

[Tiger]

Stay with Bilstein... STAY WITH BILSTEIN,,,, BIIILLLLLSSSSTTTEEEEIIIIIINNNNNN!

The other reason is your front are Bilstein too... so why mess up the balance?