Martin S.

I took my car in for a pre-track tech inspection today......damn, what a surprise I got, and an expensive one at that? Also note, the last time I drove the car it seemed to handle as well as ever, as if on rails.....these damn Porsche cars can run, even when they are broke!.

It seems the collar that holds the aluminum piece to which the drop link is
attached somehow came loose. It proceeded to rotate forward and in the process, it ripped in half due to the unusual angle drop link to the sway bar, the carnage then served as a punch to trash my left side lower A arm, NOT the wheel carrier as originally reported. Note the 993 RS drop links seem unaffected by the events.

The fix, replace the lower A arm, replace the cad plated steel mounting bracket to which the upper portion of the 993RS drop link attaches, align the car and add two (2) collars to the bloody cad plated piece to keep it from rotating forward, maybe $1,500, about 1/2 of what I originally thought.....The cost came in under $1,500, and it included the A arm replacement, lock nuts at top and bottom of sway bar adapter, tighten up the PSS9 shocks as they were backing out of their housing, reset spring height, re-check corner balance with my fat *** in car, set rear sway bar check for pre-load, check front bar for no pre-load..

This is not the first time a shock collar has come loose on me, I caught it in the past with a visual inspection. Only this time it took its toll. I was headed out to the track this weekend. I can only imagine what could have/would have happened with some G load applied. A suspension is a potential serious disaster. Thank God for tech inspections!

Word to my brothers with different Mothers, and my sisters with different Misters with coil overs, check your front and especially your rear suspension during a track weekend. It is no major effort to jack up the car between sessions to see if everything is all there. See if the paint stripe has rotated.

And finally, I really wonder what the hell is misaligned or maladjusted for the collar(s) to want to loosen up? I personally saw them tightened up, the last time we made a suspension ride height adjustment (See paragraph below).

In talking to folks that know these things, as the suspension is "worked" hard, there is a natural tendency for the drop link mounting bracket to want to rotate. It is our responsibility to check and see that the mounting collars are nice and tight. A paint stripe can be helpful.

And for you that just got to have a coil over suspension such as JIC, H&R Bilstein PSS9, etc., this can happen to you, if you let it. You have got to check your car out. Note, this cannot happen to stock, M030 or M030 (RoW) suspension. They don’t got those damn adjustable collars.

Pics are coming in a folow up post!

InTheAir

I'll definitely echo your sentiments--"thank goodness for tech inspections"!! Glad it didn't turn out worse for you.

Keep us updated on the repairs, Martin.

Basal Skull

ahh, the loose drop link mount problem....I've had this on my H&R's as well as moton's - apparently not that uncommon. I have a locking collar both on top and below my drop link mount as well as used red thread lock last time - it's held so far. The alignment of the drop links have to be right (vertical) with the suspension loaded, there's been some comments about mounting the upper drop link to the mount "inboard" vs "outboard". Viper Bob apparently has a drop link mount custom made to prevent this (for PSS9's I think). I think larger aftermarket sway bars and comming out of driveways can cause undue stress on these mounts. If you stare at it you can see the drop link forcing the mount in one direction or the other depending on how it's aligned - so align it so that it would only 'tighten' against one of the locking collars.

Bill Verburg

Martin, did it make any noise when loose?

pcar964

Would this problem be exacerbated by thicker sway bars? I ask because I currently have stock 93 sways with my PSS9s, but plan on M030 sways in the future.

Flying Finn

Damn... Good thing you noticed this before anything serious happened (wheel carrier breaking etc.).

I'd also like to hear whether you heard any noise?

I have RS Sway and I have not two locking rings as it's definitely good to have. However, I have marked the locking ring & collar and always before the track I check whether one of them has moved.

TCallas

I agree with Basal. On our pro race cars, (the 993 RSR Evos) we had to run two locking collars. One on the top and one on the bottom of each of the rear sway bar drop link mounts. We also had to be very mindful of the final clocked position to make sure that the force was not trying to loosen or turn the mount. It looks like you have plenty of room too Martin.

TheOtherEric

Martin,
Glad you caught this in time. IMHO, it doesn't need to be misaligned for this problem to occur. Since it's hard to explain, I drew a sketch (below). No snickers. When you lower a car like we've done, your drop links end up non-vertical, which puts a load component on the drop link mount that is parallel to the threads, and this can loosen the mounts. In a stock configuration, the load is against the threads and shouldn't loosen them. That's why I've been saying for a while that anyone who lowers their car like this needs a nut above & below the drop link mount. I had this problem too but I was lucky enough to catch it in time. Not everyone using only one nut will have a problem, but it's not worth the risk. Again, I'm glad you caught it in time!!

I hope this sketch clarifies the issue. As you can see, it gets worse if you use the inner-most sway bar holes.

Bill Verburg

Here's mine, the drop link collar is as low as it can go, curved RS links, locking collars above and below, I am considering buying drop links that are a little longer w/ heim joints, inside or outside the bars is still aquestion in my mind

TheOtherEric

Bill's pic doesn't really show the angle issue I referred to, do to the camera perspective. Here's a pic of a similar setup that shows the angle issue:

Wreck Me Otter

I had my aircraft aluminum drop link mount on my Moton Clubsports (w/RS sway bars) rip off and then as the drop link was flailing around the stud in the drop link ripped out. Replaced it and never had an issue since. We suspect that the drop link came loose and started hammering on the mount until it tore off.

Bruce SEA 993

Bill, The sway bar link needs to be mounted on the inside of the mount so it is between the mount and the shock body. This way the link has less leverage on the mount. The closer to the centerline of the shock body it is the less force it can exert on the mount to rotate it.

Eric also has a good point...however you need to look at it while th etires are on the ground as the picture you show has a lot of movement from drop out.

Ciao

geolab

Both front and rear sway bars, and the rear bottom control arms should be tightened with
the car standing on all 4 tyres and not raised. my .2cts
The control arms are tightened with car on the ground forcingly with alignment.
really scary what happened

GratefulJED

FWIW there was a thread earlier and I asked about the 2 collars as mine had come loose and rotated. I called Bilstein and they thought I was a noob (I am) and pretty dumb about wanting to put a collar on the top and bottom. They had never seen that done before - they said - and just said to make sure they were tight. Hmmm - I do now, and have marked mine as well to prevent further episodes. Glad you episode was not worse.

Garth S

Glad you caught it in tech inspection!

For the reasons Eric and others have noted, I added lock rings to both sides of the rear link mounts on garden variety Bilstein HD's .... with this, regardless of torque direction on the mount, it is always in a tightening/clamping mode: with only one locknut used, half of the time it is torqued in a loosening direction.