TheOtherEric

I think I've vaguely heard of this, and now I understand the problem. If you're going to install PSS9's, take notice!!

If you lower your car on your PSS9's, the rear drop link mounts have to go under the lower control arms. The attached pic shows how it typically looks (pic courtesy Boostid). Driver's side looks the same. Here's the problem: on the passenger side, there's nothing to prevent the drop link mount from spinning loose, which it will want to do since it's being pushed forward by the drop link. This happened to me, and the mount rotated forward into the drive shaft causing a bit of wear on the drive shaft. Not good. On the drivers side, this won't happen since the force from the drop link just tightens the mount against the locknut above it.

So here's my idea for the solutions:

1. Long term: on passenger side, install locknut BELOW the drop link mount. On drivers side, it stays up top. Why didn't I already know this?!

2. Short term (i.e. how to make my car driveable without removing shock): ??? Help ???

kkim

Eric,

1. I'd suggest when you do the passenger side you do the driver's side as well just for insurance. I double locked mine using with one lock ring above and one below each drop link mount.

2. sorry, can't help you, other than make it real tight and check it often.

Racer944

Interesting... I now understand the problems about this that I have been reading about... The double lock ring solution sounds good although your solution sounds perfectly adequate too Eric. I don't see any easy way to fix this without taking off the shock though. Is there anything that you can safety wire the mount to temporarily?

Out of curiosity, anyone kow if the H&R coilovers system can have the same issue?

Eric

clib

since you are almost at the bottom of the threads anyway, could you just rotate the shock a few turns so the droplink spins down to the very bottom of the threads? I beileve at the bottom of the shock the body is a larger diameter than the threads and that resistance would keep it from further rotation forward. Just a thought until you can get the shock off.

bill

loden

I recently noticed that both my rear droplinks (PSS9) were snapped with no obvious rotation of the mount. I should have two new ones (via Bilstein) today.

There have been several threads on Rennlist regarding this and a few solutions proposed.

I suspect that my mounts are rotating slightly with the suspension loading and unloading causing a lateral stress on the droplinks. I'm going to put the new links in and tighten the lock collars with a "maximum effort". If they fail again then the shocks will come off and I'll doulble lock each side.

AFAIK, it depends on which type of sway bar you have, as to whether it goes above or below the lower control arm. The RS bar or the TRG bar (they each have longer and curved droplinks) go below the arm whereas the stock bar mounts above the control arm. Bilstein's drop links supplied with the PSS9 kit are shorter than the stock links and I don't think there is any way to mount the bar below the control arm (but I'm ready to be stood corrected).

Ideally, we could source beefier, adjustable drop links......but I'm not aware of any that are available (now that Viper Bob is not doing that sort of thing for now).

Good Luck!

TrackJunke

Take a pry bar or large screw driver and tighten the ring by hitting the pry bar or screw driver with the hammer. Mine were rotating until they were tightened this way and the seem to stay put.

loden

Yes, this is my "maximum effort" plan. Glad to know it can work!

TheOtherEric

Aha. Just to show you how inexperienced I am: I actually tried tightening mine with the cheap spanner wrench supplied by Bilstein. I'll try using this more "direct" approach.

I DEFINITELY believe that extreme tightening of this upper locknut seems to mask this installation error. It was only a problem for me when I started monkeying around with the setup. Apparently I didn't tighten down the top locknut enough. But still, simply using more torque is NOT the wisest solution.

96C4S

guys does this also happen with shocks and spring set up

loden

Well, from what I've read in the archives here and elsewhere, it seems that it is a problem limited to the Bilstein threaded shock body (either PSS9 or HD's).

If other shock makes are succeptible to this, their owners have been remarkably quiet about it.

TroyN

I posted this a while back, but there's a local San Diego guy that can do the custom (shorter), beefier droplinks, mirageintl.com. No affiliation, etc, he (jae@mirageintl.com) had made me a set for my pss9's.

TheOtherEric

Just so our readers are clear, the droplink breakage issue is completely unrelated to the droplink mount spinning issue.

Bruce SEA 993

I like the ideas put forth here about tightening the lock nuts as you do not have the double lock nuts as Kelly Kim has. That is the best solution but if you don't already have the double lock nuts, tightening them is the way to go. Viper Bob did have a split ring solution but I am not sure it is still available.

I am a ittle confused on your statement in the first post that the passenger side would loosen and the drivers side would tighten. That would mean you only drove on right handed turns. The sway bar links impart loads pushing and pulling on the mounts depending on right or left turns.

Again the key is having double lock nuts per Kelly Kim or John Reese or tighten the hell out of them.

loden

Thanks for the lead TroyN. I'll bookmark the site in case I snap these new Bilstein droplinks that just arrived!

OtherEric, yes, the link mount spinning is an issue by itself, the most important complication being what was happening to your car.....damage to the drive shaft (I think someone reported damage to a control arm also).

I am suspecting however, that this mount instability also shortens the life of the drop link (just a theory), as a lot of people running the stock sway seem to have a problem with snapping the (relatively wimpy) Bilstein drop links and the obvious fact that loose droplink mounts on the PSS9's and HD's are endemic.

kkim

For clarification... my setup with lock rings, above and below the sway bracket w/ shortened drop links from ViperBob.

Have never had a problem with them loosening up or drop link breakage. I would venture to guess if anything is the weak link in my setup, it would be the bracket itself at this point.