Shock Absorber test accuracy

[virus-zn]

Was hoping someone could help, I have the F30 320d modernline, car is doing 35k kms and feels like Im floating along and then when I go over a bump it just bounces, took it into the dealer and they say this is normal, the dealer then says I can take it for a shock test to confirm if the shocks are poked. So took it into Hi-Q for a shock test and they say that the shocks are poked. Went back to dealer and they say they inspected the shocks and they are fine. Just wanted to know how accurate these shock tests are and whether I will be fighting a losing battle.

 

[DieselFan]

Try drive another f30 modernline and see if it's the same

 

[Ralf*]

How did HiQ test the shocks..?

The Jury is still out on the accuracy and reliability of those "electronic" shock testers.

At 35K km's, it is strange that the shocks are gone, unless you have abused them, ie potholes, impact damage, seriously rough roads....most shocks are good for around the 100k km's mark...or longer.

we don't have any fancy equipment in our shop, but mainly rely on the technicians experience, on how solid the car feels....
They normally check to see how long the car osscilates after an upsetting input, with good shocks the car almost immediately only rocks once before it returns to a stable state, worn shocks and the car osscilates a good few times longer, before it returns to a stable state....similar to a Sin or Cosine curve (mathematics)

 

[MikeR]

:thumbs: agreed - I dont believe all 4 shocks would go at such short mileage - possibly one only, they should get 100+k

 

[sash]

the only shock test i would trust is the one that is fitted into the floor, starts to move the wheel up and down to a certain point and then allows the shock to stop the movement.

I feel these would be more accurate than the machine than is attached to the fender and the car is pushed down or even just a mechanic pushing down on the car as alot can depend on whether the mechanic had weetbix or all bran flakes that week :rollsmile:

 

[Auditor]

My opinion is that those electronic shock testers are unreliable. Any camber in the strut setup just masks shock failure. In my experience the only way to be sure is to completely remove the shock and visually inspect it for leaks and then test the resistance by hand.

 

[moranor@axis]

unfortunately there is no real way to test a shock unless you run it on a damper dyno and compare to the expected curve this is not a cost effective solution given the equipment involved

I would take the car to another dealer till you find one that will change them

 

[Nikhil]

you under motorplan just swear them and get them to replace it :thumbs:

 

[phantom]

The roadworthy test stations have the right equipment to test and if they fault the shocks the dealer will have to replace.
Your symptom to me reflects you may have a tyre problem.

 

[sash]

unfortunately there is no real way to test a shock unless you run it on a damper dyno and compare to the expected curve this is not a cost effective solution given the equipment involved

I would take the car to another dealer till you find one that will change them

I never thought about this, different shocks function differently.

I assume that a standard shock would have a different curve to sport or shortened shocks.

 

[moranor@axis]

unfortunately there is no real way to test a shock unless you run it on a damper dyno and compare to the expected curve this is not a cost effective solution given the equipment involved

I would take the car to another dealer till you find one that will change them

I never thought about this, different shocks function differently.

I assume that a standard shock would have a different curve to sport or shortened shocks.

correct and the shape of the curve has a huge impact on performance and feel much like the torque curve on an engine dyno

 

[Onyx]

http://www.gabriel.co.za/page30.html

Have the test done. If it gets the red light then surely the dealership is obliged to replace the shocks?

 

[virus-zn]

Thanks for the feedback guys, will probably be looking at getting a set of aftermarket springs hoping that might improve the ride, really not enjoying the ride right now . Anyone know where i can get aftermarket springs for the F30 ? Also looking for a set of 19 rims and tyres, where would be the best place to start ?

 

[Photokid]

Thanks for the feedback guys, will probably be looking at getting a set of aftermarket springs hoping that might improve the ride, really not enjoying the ride right now . Anyone know where i can get aftermarket springs for the F30 ? Also looking for a set of 19 rims and tyres, where would be the best place to start ?

Installing aftemarket, lowered springs without changing to the correct dampers will only increase the wear on your standard shock. If the dampers are already shot, the ride will only worsen.
To what car are you comparing the ride quality over bumps etc? What was your previous vehicles?

 

[moranor@axis]

http://www.gabriel.co.za/page30.html

Have the test done. If it gets the red light then surely the dealership is obliged to replace the shocks?

Bushings and Tires will skew the results... this is why the dampers need to be taken off the car for a proper test

Thanks for the feedback guys, will probably be looking at getting a set of aftermarket springs hoping that might improve the ride, really not enjoying the ride right now . Anyone know where i can get aftermarket springs for the F30 ? Also looking for a set of 19 rims and tyres, where would be the best place to start ?

I can provide springs from Eibach or H&R but these will not fix your problem... you need to fix the real problem not try mask it by changing other parts... change the dampers 1st then lower if you want to

 

[virus-zn]

Previous car was the W203 Merc Sportpack, so was thinking maybe I am just used to the stiffer suspension on the old car, but this car feels really unsafe going around bends, feels like its going to roll over . Have not enjoyed driving the car since I got it since I am afraid of pushing it too hard around bends and that's the most fun part of driving

 

[moranor@axis]

If you really want to upgrade the performance you need to fit uprated dampers springs alone dont make that much difference

 

[sash]

There should be a marked difference between the comfortline and msport models but both should feel 'safe' around corners. I would suggest test driving another comfortline similar to yours as suggested above to compare.