sudden release of shock pressure?

CaifanSC

SCCoA Member
So this has happened to me two times in the chameleon car within the past 2 months.

First time I was sitting at a light and all of a sudden felt a pretty evident change in ride height in the rear of the car...my first inkling was that I had a flat tire. So i make the turn and pull over and all tires are fine. I just thought it was the weirdest thing! but no harm was evident so forgot about it.

Last week it happened again while I was getting coffee in the drive through...it's sudden so i have not been able to tell if its specific to one side, but it feels like the car suddenly bulks down....but the suspension feels fine otherwise...surprisingly so. These stock shocks on the 95 feel firmer at times than the aftermarket tokiko illuminas in my 94.

Do shocks tend to have this sudden loss of pressure when they go bad? I was under the impression that if they go bad...that's it...they collapse and make rattling sounds and lose all dampening properties. That's not the case with mine which confuses me a bit.

Any thoughts?

Thanks!
 
Dumb thought, I'm having tranny issues in my 90, when the tranny isn't fully warmed up and I come to a stop, it disengages itself from the drivetrain. Almost like putting the shifter in neutral. Let it set in gear for a few seconds then I can fell it reengage. Like putting it back in drive. Is this possible?

Ride control only adjusts the valving of the struts. Nothing to do with the ride height. Might try flipping between firm and normal to see if it responds.

Ride height might be affected if they're worn but being intermittent is not something that usually happens. Weird.....

JJ
 
My all original 90 used to do the exact same thing. It would feel like something jacked up the rear right side of the car suddenly when I was sitting at a light, accompanied by a soft thud from the trunk area. It rode fine, no noises otherwise and the arc still worked. But every once in a while it would do that. It almost felt like something was binding and suddenly released. Then it would drop again after taking off. I drove it like that for years until I sold it and never had an issue.
 
My all original 90 used to do the exact same thing. It would feel like something jacked up the rear right side of the car suddenly when I was sitting at a light, accompanied by a soft thud from the trunk area. It rode fine, no noises otherwise and the arc still worked. But every once in a while it would do that. It almost felt like something was binding and suddenly released. Then it would drop again after taking off. I drove it like that for years until I sold it and never had an issue.

I get that in my '90 - not the shocks, not the rear calipers, not the front diffs mounts, as it did it before and after replacement of all pairs. I finally decided it was the diff lock plates releasing as the drivetrain relaxed.
 
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Shock valving has no effect on ride height.

Unless that valving sticks and then releases - pretty rare w/modern shocks I think...not something I've seen since abusing air-over off road shocks when the housing got dented. A balking shock can also happen when the main shaft gets dinged/bent and hangs up on the seal.

On our cars I'd be looking for mounts that weren't tightened correct and suffer from wrap-up on either end, or a bad upper pivot on the front. An extreme case would be a cracked body...
 
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Good afternoon

I also had this issue. Rear felt as if it dropped with a "thud" during acceleration and stop. More noticeable (noise) on the left side (diver rear). In my case it was the diff mounts. At first glace they looked OK for a 140K+ car. I replace them with 97 mounts from the salvage yard. The first thing I noticed was the mount "compression". They were not as "flat" as the previous set. Next was the somewhat new "position" of the diff. The mounts did not "pull through" the diff collars especially at the top. The thud noise and the low "drop" did not come back. As KMT stated one possible cause is mount.

Good Luck.
 
Interesting...so are you guys referring to the round mounts at the front of the diff? or the big square flange at the rear of the diff housing? Now that you mention it I do also hear some weird clunky rattling that I was not sure what it was.
 
Interesting...so are you guys referring to the round mounts at the front of the diff? or the big square flange at the rear of the diff housing?

Either when shot isn't good - the rear mount on mine is still intact, and the fronts looked ok from the outside, but I was converting the low hanging fruit to red poly and decided to renew/convert the fronts. Found out the right upper and lower had deformed and weren't as tall/sat slanted compared to the left side, making me wonder if that meant play and I'd found the clunk, but even with the new reds installed the sound remained.

I've checked u-joints, and the motor and trans mounts have been refreshed, so it's not them. The exhaust hangers and clamps are all good, so that system isn't it either. I even jacked the car up and dropped it to see if I could make the noise happen, but no luck. In fact I couldn't replicate it in the driveway...just when out driving around, after stopping and relaxing the brakes, but not every time.

My diff fluid was low, so I topped it off with Ford's track-lock juice and thought that made a difference for a while, but it's still there now - diff performs as advertised otherwise. Nothing is falling off the car and it's not really that loud, so until it gets worse, I'm just living with it. Interesting that others seem to hear it too, tho.
 
Dumb thought, I'm having tranny issues in my 90, when the tranny isn't fully warmed up and I come to a stop, it disengages itself from the drivetrain. Almost like putting the shifter in neutral. Let it set in gear for a few seconds then I can fell it reengage. Like putting it back in drive. Is this possible?
Whats happening is the fluid sloshes forward and the uncovers the filter intake hole which allows the pump to pull in air. The loss of pressure causes the clutches to disenaged until the fluid settles back and pressure is restored. Check fluid level on level ground, engine running, and make sure its at the top of the hash mark and the problem should go away.
 
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