Street car blowing out Bilstein front inserts....

I have run Bilstein HDs on all my cars for 20 years without problems and now have blown both front inserts on my 1995 Audi S6 Avant (aka giant pig at 3900lbs) in just one year.

Right front went out last February during a cold spell.

Left front went out last week during a cold spell.

And when I say cold, I am not talking about our current polar vortex, I am talking about temps in the 20 to 30 degree F range (Washington DC area) not the upper midwest minus 20-degree F range.

What gives?
Just unlucky?
Valving wrong?
Internal bump stops too short?

Part number 34-003701


Do I need JVAB fronts with a fixed perch for a street car?

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____________________________________________________________-

One. Class -- 2WD

www.quantumrallysport.com

http://www.facebook.com/home.php?#/pages/Quantum-Rally-Sport/281129179600?ref=nf

I'll splain later, gotta go get me girlies at school.

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

Splain please! For some reason the Audi guys swear at Bilsteins rather than swearing by them. Seems like they fail rapidly, heaving the seals out or something.

I gots to know, since I'd like to run Rabbit inserts in the front of my latest acquisition (you cut the strut tubes 40mm and use Rabbit inserts and you get the car lower, which is really kinda something the car desperately needs)

PS - At -15 degrees, the ATF in the power steering turns into gel and the P/S pump sounds like a Paxton.

---

Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.



Edited 1 time(s). Last edit at 01/06/2014 08:58PM by Pete.

Quote
Pete
Splain please! For some reason the Audi guys swear at Bilsteins rather than swearing by them. Seems like they fail rapidly, heaving the seals out or something.

I gots to know, since I'd like to run Rabbit inserts in the front of my latest acquisition (you cut the strut tubes 40mm and use Rabbit inserts and you get the car lower, which is really kinda something the car desperately needs)

PS - At -15 degrees, the ATF in the power steering turns into gel and the P/S pump sounds like a Paxton.

OK normal zimmering seal you have rubber lip and the light spring inside making some pressure on the lips which seal shaft...

Take the spring out and it may wipe but prolly won't "seal" real well.

Shaft seal on all DeCarbon designed stuff---mono-tube with floating piston and gas on the other side there is no spring on the seal. It is the gas in the chamber pushing on piston pushing on OIL which affects the sealing force...

Internally the cgas chamber might be 46mm dia x maybe 35-38mm, not a big volume of gas...but enough to do what it's supposed to do ---and that is accommodate the displaced volume of oil of the rod when the rod/shaft comes INTO the body on compression..
Works good, leaves a very very thin layer of oil which means seal life is OK for a bazillion miles.

No what happens to gas pressure wif LOW temp? Yep it always falls..
What happens to gas pressure when wif used stuff a shock as expended some oil volume lubing the shaft for XXXXXXX many strokes. Gas piston moves-----> compensating for less oil gas pressure drops .
So used, drops, and temp drops...

Pressure drops---seal maybe don't seal too "hot".

Maybe that's why a few times I had the backs of my riding pants and the back of the boots covered in not even piss-warm oil when I was merrily riding in zero degree F weather


Alternate is temps plummet, oil turns to tootsie roll consistency---force is applied, pressure spikes to millions of PSI and vomits oil out.

Alternate is distinct possibility, first thing was direct observed..

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

Not sure you answered my question. Why does it seem to happen only to Audis?

Lack of drain hole in strut housing?

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____________________________________________________________-

One. Class -- 2WD

www.quantumrallysport.com

http://www.facebook.com/home.php?#/pages/Quantum-Rally-Sport/281129179600?ref=nf

I thought that, but Bilstein strut assemblies don't have drain holes in them.

Something to do with the steering arm mounted up high eating bushings and making the seals heave? I remember that being a big problem on J-cars (the ones that looked like morphodited front drive Kadetts) where they struts would develop tons of play. But you'd think that of all the struts out there, the upside down design would be the least likely to have that problem.

And shitty struts from Koni and others don't have that problem, so that is not likely to be it.

---

Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.



Edited 1 time(s). Last edit at 01/07/2014 12:05PM by Pete.

Valving on the urs struts is super soft. I think they generate much higher speeds/more cycles and just plain wear themselves out sooner.

CQ REAR
HD’s P36-3017
Compressed: 440.0 / 17.32
Extended: 538.5 / 21.20
Travel: 98.5 / 3.88”
Valving: 197/47 Comp/Rebound

Sports P36-3058
Compressed: x / 17.32
Extended: x / 20.41
Travel: x / 3.09”
Valving: 196/47

UR-Q Fronts - P36-3016
Compressed: 435.0 / 17.13”
Extended: 548.5 / 21.59”
Travel: 113.5 / 4.47”
Valving: 174/43 Comp/Rebound

S4 Front Shocks
P36-0370 “HD”
Compressed: 17.28”
Extended: 22.1”
Travel: 122.42mm / 4.82”
Valving: 113/101 Comp/Rebound

P36-0369 “Sport (front)”
Compressed 17.25”
Extended: 21.25”
Travel: 3.92”
Valving: 113/101 Comp/Rebound

Quote
aj_johnson
Valving on the urs struts is super soft. I think they generate much higher speeds/more cycles and just plain wear themselves out sooner.

CQ REAR
HD’s P36-3017
Compressed: 440.0 / 17.32
Extended: 538.5 / 21.20
Travel: 98.5 / 3.88”
Valving: 197/47 Comp/Rebound

Sports P36-3058
Compressed: x / 17.32
Extended: x / 20.41
Travel: x / 3.09”
Valving: 196/47

UR-Q Fronts - P36-3016
Compressed: 435.0 / 17.13”
Extended: 548.5 / 21.59”
Travel: 113.5 / 4.47”
Valving: 174/43 Comp/Rebound

S4 Front Shocks
P36-0370 “HD”
Compressed: 17.28”
Extended: 22.1”
Travel: 122.42mm / 4.82”
Valving: 113/101 Comp/Rebound

P36-0369 “Sport (front)”
Compressed 17.25”
Extended: 21.25”
Travel: 3.92”
Valving: 113/101 Comp/Rebound

That is really soft on compression eh? And not a lot of stroke (although more than any of the others)

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____________________________________________________________-

One. Class -- 2WD

www.quantumrallysport.com

http://www.facebook.com/home.php?#/pages/Quantum-Rally-Sport/281129179600?ref=nf

Just an un educated conjecture. But comparing to other "sport" sedans ie bmw it seems soft to me. Hopefully john will tell me if I'm a misguided child of yhe internet.

Holy crap that's no travel.

I forget if Ur-Qs have 4000 tubes in 5000 bearing housings or 5000 tubes in 4000 bearing housings... probably the latter. I remember that it's a mix of small chassis and big chassis, though. Friggin' goofy handmade cars.

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Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.

Blew another this week in the cold....

arrrgh

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____________________________________________________________-

One. Class -- 2WD

www.quantumrallysport.com

http://www.facebook.com/home.php?#/pages/Quantum-Rally-Sport/281129179600?ref=nf

I've got koni's in my current car, and had them in the last car. Haven't blown one "prematurely", but also havent seen much colder than 15* F YMMV. (both cars had koni's when I bought them)

Quote
Josh Wimpey
Blew another this week in the cold....

arrrgh

Welcome to Audi ownership?

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Grant Hughes

The warranty is easy enough and this is the only car I know of that you can do the strut without removing eh wheel & tire or springs....

I have had Billsteins on lots of cars for lots of years and never had this issue

---

____________________________________________________________-

One. Class -- 2WD

www.quantumrallysport.com

http://www.facebook.com/home.php?#/pages/Quantum-Rally-Sport/281129179600?ref=nf

Josh, YGPM.

---

Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.