Blown AST coilovers?

fourdegrees · 02-20-2008, 04:16 PM

Allow me to set the situation:

I just recently installed a 24mm rear sway bar (whiteline) and I have noticed what can be described as a crash or thud from the passenger side rear when going over sharp bumps. There is no noise when going around corners or weaving back and forth, shifting the weight from side to side. The noise is only there when I hit a sharp bump. Manhole covers and railroad tracks would be a good example.

I automatically assumed something was loose or I didn't apply enough grease to the bushings. So, I crawled underneath and re-tightened everything and applied more grease to the bushings. No luck. The noise is still there.

Now, I've always noticed a small amount of noise from that side, but nothing like the noise now. I looked again today to see if bar was making contact with something under the car. I didn't see any obvious witness marks. What I did notice was a noticeable amount of moisture on the upper threads of the strut body and noticeable amounts of moisture on the strut shaft itself. There is also a good amount of road grime built up. The other three struts are dry with only dust and dirt on the strut body.

Is the fluid a dead giveaway for a strut on its way out?

Is it possible that the noise I was hearing before the install of the swaybar was the strut loosing its ability to dampen the springs movement? Has the addition of a large swaybar only made it worse?

***BoostJunkie*** · 02-20-2008, 05:15 PM

Usually fluid on the strut body is not a good sign. I'd contact the vendor who you bought them from and send them pics. That way they can get in touch with AST and see what's up. My guess is that damper will need to be rebuilt though.

**tyler_sti** · 02-20-2008, 05:23 PM

Most likely a rebuild. Excessive fluid means it's leaking of course. So no matter what it is leaking, especially if the other's don't show the same signs.

**twiSTies** · 02-20-2008, 05:31 PM

what ASTs?

fourdegrees · 02-20-2008, 06:37 PM

I bought them from rallispec 2 years ago. They are part # 4622s-0003 through 4622s-006. They aren't the TIC version.

***BoostJunkie*** · 02-20-2008, 06:41 PM

Give Dave at Rallispec a call tomorrow, he'll take care of you.

stretch · 02-20-2008, 06:50 PM

The clang might be unrelated to the blown strut. I didn't like the way the AST's mounted in the rear. You might try calling TiC and to see if they can get you some different mounts for the rear since TiC switched to a different style than what AST shipped with.

fourdegrees · 02-20-2008, 06:59 PM

Thanks stretch. I'm worried about the clang as well, probably more so than the fluid on the strut itself for the time being. I would be upset if I fixed the strut, which I suspect is going because of the fluid, but didn't fix the clang which was my original issue in the first place.

This is just my hypothesis, please tell me if I'm way of base. If a strut starts to go, is it possible that it would have a problem stopping the sway bar from hitting the lower inner corner of the wheel well. Right where it makes the turn to attach to the endlink. There is a little bit of witnessing right there. The springs are light, only 3k, so they wouldn't provide much resistance to a sharp bump. So I hit a pothole, the spring is basically undampened, the entire suspension moves up, bringing the swaybar with it, hitting the bottom of trunk near the inner part of the wheel well. Does that sound plausible? And would it be plausible that the clunk/bang is louder since I just put on a larger rear bar?

**Turninconcepts.com** · 02-21-2008, 03:40 AM

pull the damper and compress it by hand. if it comes back up smoothly then it's fine. If it doesn't come up smoothly or doesn't come up then it needs to be rebuilt.

I would just directly contact AST-USA and see how the warranty on those is going to work since you bought them before they were over here and all that.

stretch · 02-21-2008, 06:12 AM

Quote:

Originally Posted by fourdegrees

Thanks stretch. I'm worried about the clang as well, probably more so than the fluid on the strut itself for the time being. I would be upset if I fixed the strut, which I suspect is going because of the fluid, but didn't fix the clang which was my original issue in the first place.

This is just my hypothesis, please tell me if I'm way of base. If a strut starts to go, is it possible that it would have a problem stopping the sway bar from hitting the lower inner corner of the wheel well. Right where it makes the turn to attach to the endlink. There is a little bit of witnessing right there. The springs are light, only 3k, so they wouldn't provide much resistance to a sharp bump. So I hit a pothole, the spring is basically undampened, the entire suspension moves up, bringing the swaybar with it, hitting the bottom of trunk near the inner part of the wheel well. Does that sound plausible? And would it be plausible that the clunk/bang is louder since I just put on a larger rear bar?

I'm confused in two places- you're running 3kg/mm rear springs? That's absurdly soft if I'm understanding you correctly. The stock rear springs are 3.5kg/mm rear, and the default AST rates I know about are 5kg/mm in the rear.

Secondly, no, a blown shock shouldn't make a sway bar hit anything. A blown shock might be more prone to bottoming out, but a sway bar should have enough clearance not to hit anything even when bottomed out. What sway bar are you running, and with what endlinks? Can you take pictures?

Like TiC said, you're going to need to pull the strut and examine it. If it's leaking fluid, that is a big deal. Did your coilovers have dust boots to protect the seals from dirt? The new AST-USA dampers have a lifetime warranty, but I'm not sure that your AST's have that since they were bought before AST-USA existed.

fourdegrees · 02-21-2008, 06:41 AM

Stretch,

3k is really soft, but that's what they were shipped to me with. 5k with helpers in the front and 3k with helpers in the rear. When I got them two years ago I was told that AST had been experimenting with soft springs and I happened to get the really soft iteration. In fact the boys on scoobynet.uk were suggesting 5k front 4k rear for the 'new age' stis, so I eventually felt comfortable with the 3k springs.

I eventually removed the helpers in the rear due to a lack of clearance with my tires. Apparently the UK Imprezas were showing the same lack of clearance at the time and powerstation was telling folks to just remove the helpers. So right no I'm running 5k with 2k helpers in the front and 3k with no helpers in the rear. 200mm free length mains with 100 free length helpers up front. 250mm free length mains in the rear.

The swaybar is a 24mm whiteline on the softest setting with stock endlinks.

I can take pictures after they stop digging up my front yard.

fourdegrees · 02-21-2008, 07:05 AM

Stretch,

I forgot to mention that they do have dust shields, the kind that are plastic and attached to the bumpstop, but the one in question has broken off.

stretch · 02-21-2008, 07:05 AM

Wow. Well, here's my guess, but I don't really know all the specifics of your design. Don't be alarmed since my scenario is unlikely, but it would explain everything.

The rear springs were coil binding due to their soft rate. You'd have to run 12" springs or longer at those rates which simply wouldn't fit. They probably used a 9" or 10" spring which, at that rate, won't be long enough.

Due to the rear upper mount of the AST coilovers, the designed was damaged from the coil bind, which sends exponentially greater stresses through the mounts. My guess is the upper mount bent.

The bent upper mount has put uneven forces on the strut shaft, causing uneven seal wear and thus the fluid leakage.

These are all the issues that TiC had to fix when making their own AST-based coilover product. I'm both surprised and saddened if my prediction is true; a suspension company should know better.

I think you really need to remove your strut and take a look before this goes any further.

fourdegrees · 02-21-2008, 07:30 AM

The length is 250mm, which, like you said is probably too short.

I've always felt that they were too soft to begin with, but like I said, I heard reassuring words from across the pond, so I went with it. However, I was planning to upgrade to stiffer springs from swift when I rebuilt them. Looks like my chance has come sooner than later. Maybe when I get them rebuilt I can have them adjust the valving for the higher spring rates of something along the lines of the TIC coilovers. Not the same of course, because I'm sure that's proprietary information.

fourdegrees · 02-21-2008, 01:55 PM

Here is a picture of the swaybar and endlinks. Notice the well lubed bushing.

02-20-2008, 04:16 PM	#1
fourdegrees Junior STI Driver Posts: 162 Join Date: Jul 2004 Trader Rating: (0)	Blown AST coilovers? Allow me to set the situation: I just recently installed a 24mm rear sway bar (whiteline) and I have noticed what can be described as a crash or thud from the passenger side rear when going over sharp bumps. There is no noise when going around corners or weaving back and forth, shifting the weight from side to side. The noise is only there when I hit a sharp bump. Manhole covers and railroad tracks would be a good example. I automatically assumed something was loose or I didn't apply enough grease to the bushings. So, I crawled underneath and re-tightened everything and applied more grease to the bushings. No luck. The noise is still there. Now, I've always noticed a small amount of noise from that side, but nothing like the noise now. I looked again today to see if bar was making contact with something under the car. I didn't see any obvious witness marks. What I did notice was a noticeable amount of moisture on the upper threads of the strut body and noticeable amounts of moisture on the strut shaft itself. There is also a good amount of road grime built up. The other three struts are dry with only dust and dirt on the strut body. Is the fluid a dead giveaway for a strut on its way out? Is it possible that the noise I was hearing before the install of the swaybar was the strut loosing its ability to dampen the springs movement? Has the addition of a large swaybar only made it worse? This ad is not endorsed by this member. Please register or login to hide this ad.

02-20-2008, 05:15 PM	#2
*BoostJunkie* Sold My Soul For Mods Car: '05 CGM STi Fav Mod: Track Time Location: Bethesda, MD Posts: 6,554 Join Date: Jun 2004 Trader Rating: (14)	Re: Blown AST coilovers? Usually fluid on the strut body is not a good sign. I'd contact the vendor who you bought them from and send them pics. That way they can get in touch with AST and see what's up. My guess is that damper will need to be rebuilt though.

02-20-2008, 05:23 PM	#3
tyler_sti Gold Member Car: '07 CMG STI Fav Mod: Not knowing how to "spell" hah Location: los angeles Posts: 3,729 Join Date: Aug 2006 Trader Rating: (15)	Re: Blown AST coilovers? Most likely a rebuild. Excessive fluid means it's leaking of course. So no matter what it is leaking, especially if the other's don't show the same signs.

02-20-2008, 05:31 PM	#4
twiSTies Gold Member Car: 05 Subaru WRX STi Fav Mod: T2s and Recaros Location: Allentown, PA Posts: 3,228 Join Date: Oct 2005 Trader Rating: (7)	Re: Blown AST coilovers? what ASTs?

02-20-2008, 06:37 PM	#5
fourdegrees Junior STI Driver Posts: 162 Join Date: Jul 2004 Trader Rating: (0)	Re: Blown AST coilovers? I bought them from rallispec 2 years ago. They are part # 4622s-0003 through 4622s-006. They aren't the TIC version.

02-20-2008, 06:41 PM	#6
*BoostJunkie* Sold My Soul For Mods Car: '05 CGM STi Fav Mod: Track Time Location: Bethesda, MD Posts: 6,554 Join Date: Jun 2004 Trader Rating: (14)	Re: Blown AST coilovers? Give Dave at Rallispec a call tomorrow, he'll take care of you.

02-20-2008, 06:50 PM	#7
stretch Silver Member Car: Aspen 2005 STi Fav Mod: TurnInConcepts.com Coilovers Location: Silver Spring, MD Posts: 1,811 Join Date: Mar 2006 Trader Rating: (2)	Re: Blown AST coilovers? The clang might be unrelated to the blown strut. I didn't like the way the AST's mounted in the rear. You might try calling TiC and to see if they can get you some different mounts for the rear since TiC switched to a different style than what AST shipped with.

02-20-2008, 06:59 PM	#8
fourdegrees Junior STI Driver Posts: 162 Join Date: Jul 2004 Trader Rating: (0)	Re: Blown AST coilovers? Thanks stretch. I'm worried about the clang as well, probably more so than the fluid on the strut itself for the time being. I would be upset if I fixed the strut, which I suspect is going because of the fluid, but didn't fix the clang which was my original issue in the first place. This is just my hypothesis, please tell me if I'm way of base. If a strut starts to go, is it possible that it would have a problem stopping the sway bar from hitting the lower inner corner of the wheel well. Right where it makes the turn to attach to the endlink. There is a little bit of witnessing right there. The springs are light, only 3k, so they wouldn't provide much resistance to a sharp bump. So I hit a pothole, the spring is basically undampened, the entire suspension moves up, bringing the swaybar with it, hitting the bottom of trunk near the inner part of the wheel well. Does that sound plausible? And would it be plausible that the clunk/bang is louder since I just put on a larger rear bar?

02-21-2008, 03:40 AM	#9
Turninconcepts.com Authorized Vendor Car: 04/08STI 95SVX 86E30 Posts: 5,070 Join Date: Jul 2003 Trader Rating: (53)	Re: Blown AST coilovers? pull the damper and compress it by hand. if it comes back up smoothly then it's fine. If it doesn't come up smoothly or doesn't come up then it needs to be rebuilt. I would just directly contact AST-USA and see how the warranty on those is going to work since you bought them before they were over here and all that.

02-21-2008, 06:41 AM	#11
fourdegrees Junior STI Driver Posts: 162 Join Date: Jul 2004 Trader Rating: (0)	Re: Blown AST coilovers? Stretch, 3k is really soft, but that's what they were shipped to me with. 5k with helpers in the front and 3k with helpers in the rear. When I got them two years ago I was told that AST had been experimenting with soft springs and I happened to get the really soft iteration. In fact the boys on scoobynet.uk were suggesting 5k front 4k rear for the 'new age' stis, so I eventually felt comfortable with the 3k springs. I eventually removed the helpers in the rear due to a lack of clearance with my tires. Apparently the UK Imprezas were showing the same lack of clearance at the time and powerstation was telling folks to just remove the helpers. So right no I'm running 5k with 2k helpers in the front and 3k with no helpers in the rear. 200mm free length mains with 100 free length helpers up front. 250mm free length mains in the rear. The swaybar is a 24mm whiteline on the softest setting with stock endlinks. I can take pictures after they stop digging up my front yard.

02-21-2008, 07:05 AM	#12
fourdegrees Junior STI Driver Posts: 162 Join Date: Jul 2004 Trader Rating: (0)	Re: Blown AST coilovers? Stretch, I forgot to mention that they do have dust shields, the kind that are plastic and attached to the bumpstop, but the one in question has broken off.

02-21-2008, 07:05 AM	#13
stretch Silver Member Car: Aspen 2005 STi Fav Mod: TurnInConcepts.com Coilovers Location: Silver Spring, MD Posts: 1,811 Join Date: Mar 2006 Trader Rating: (2)	Re: Blown AST coilovers? Wow. Well, here's my guess, but I don't really know all the specifics of your design. Don't be alarmed since my scenario is unlikely, but it would explain everything. The rear springs were coil binding due to their soft rate. You'd have to run 12" springs or longer at those rates which simply wouldn't fit. They probably used a 9" or 10" spring which, at that rate, won't be long enough. Due to the rear upper mount of the AST coilovers, the designed was damaged from the coil bind, which sends exponentially greater stresses through the mounts. My guess is the upper mount bent. The bent upper mount has put uneven forces on the strut shaft, causing uneven seal wear and thus the fluid leakage. These are all the issues that TiC had to fix when making their own AST-based coilover product. I'm both surprised and saddened if my prediction is true; a suspension company should know better. I think you really need to remove your strut and take a look before this goes any further.

02-21-2008, 07:30 AM	#14
fourdegrees Junior STI Driver Posts: 162 Join Date: Jul 2004 Trader Rating: (0)	Re: Blown AST coilovers? The length is 250mm, which, like you said is probably too short. I've always felt that they were too soft to begin with, but like I said, I heard reassuring words from across the pond, so I went with it. However, I was planning to upgrade to stiffer springs from swift when I rebuilt them. Looks like my chance has come sooner than later. Maybe when I get them rebuilt I can have them adjust the valving for the higher spring rates of something along the lines of the TIC coilovers. Not the same of course, because I'm sure that's proprietary information.

02-21-2008, 01:55 PM	#15
fourdegrees Junior STI Driver Posts: 162 Join Date: Jul 2004 Trader Rating: (0)	Re: Blown AST coilovers? Here is a picture of the swaybar and endlinks. Notice the well lubed bushing. This ad is not endorsed by this member. Please register or login to hide this ad.