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Employing Matwiz' theory, would this be a viable test for worn front shocks?

1K views 2 replies 3 participants last post by  edjack 
#1 ·
REFERENCE: MatWiz' abs-shock cross-interaction theory ...

Employing MatWiz' abs-shock cross-interaction theory, would this be a viable test for worn front shocks?

TEST 1:
1. Find empty parking lot with normal-sized speed bumps
2. Drive over speed bumps at slightly faster than you'd normally go
3. Near the top of the speed bump, brake slightly harder than normal
DATA POINT:
- If you experience unnatural violent shudder, then your front shocks are worn; (buy new Sachs, Bilsteins, or Koni's). (see ABS-pulsation PS below)
- Else, your front shocks are ok (or your ABS module is bad).

TEST 2:
a. Open hood and disconnect ABS control module harness cable (or just pull the ABS fuse).
b. Repeat MatWiz' abs-shock cross-interaction test
c. Reconnect the ABS control module harness connection
DATA POINT:
- Nobody, to date, has ever experienced the unnatural shudder under these conditions; so you shouldn't either, even with bad shocks.

PS: We know all about what ABS pulsation feels like; this isn't it; it's muuuuch more violent and it's felt totally differently.

 
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#2 ·
This sounds more like a test to determine if your ABS module is working properly rather than "Would this be a viable test for worn front shocks". Since "Nobody, to date, has ever experienced the unnatural shudder under these conditions; so you shouldn't either, even with bad shocks" then the unatural shudder would appear to indicate a different fault (e.g. ABS) and not worn shocks. Also when you refer to shudder, do you mean feedback in the steering wheel or the brake pedal. When my ABS actuates, I feel it in the brake pedal but not in the steering wheel.

I don't know of any procedure to objectively determine wear level of shocks other than my butt meter :). Determining when to replace shocks is very subjective since the change in dampening is so gradual over such a long period of time. It is probably better to use accumulated mileage as a guideline rather than some test. I replaced my front struts after 75K of NE driving and they still felt OK. But the car felt a LOT better after the change. Do shocks absolutely need to be replaced at some arbitrary mileage? Probably not as it depends on the driving history and road conditions. Can you feel the difference when you put new shocks in? Most definitely yes. I guess for most, replacement of shocks depends more upon the driver's desire for a new car ride and the state of the wallet, as this isn't a cheap fix. Of course, blown shocks are another matter and can be easily detected by the bounce test and should be replaced as a matter of safety.
 
#3 ·
Actually, the speed bump test is as good as any. Drive over them at a fast walking speed. The suspension should jounce, rebound, and stop at the neutral position. Any more movement than that shows that the shocks are worn, and not damping properly.

Look for smooth, gradual speed bumps, not agressive ones.
 
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