Dangerous failure modes in a high mileage S2000
Registered User
Joined: Jul 2010
Posts: 3
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My 00 AP1 upper mount failed at Buttonwillow Cotton corners. Colatkitty's also failed there (AP1, 02 I think). Another member's failed at SMMR this past weekend (also a 02 AP1 if I recall), he'll probably post some pics soon.
The guys who rewelded the mount said there's three layers of sheet metal there but the mount is only spot welded to the outer layer. They drilled out the spotwelds and "rosette" welded thru to all three layers, beefing up the entire area. They also seam welded the perimeter of the mount.
Also watch out for these other popular catastrophic failures:
Bump steer kit (mine went at SOWs and wiped out my rear SRC damper reservoir)
Diff failure (after ~180k, took a while but it went, fortunately while I was cooling off in the paddock).
Also replace your bearings once you start hearing the squeak/squeak/squeak...
I've been tracking this chassis since '00 and frequently visit the dirt.
The guys who rewelded the mount said there's three layers of sheet metal there but the mount is only spot welded to the outer layer. They drilled out the spotwelds and "rosette" welded thru to all three layers, beefing up the entire area. They also seam welded the perimeter of the mount.
Also watch out for these other popular catastrophic failures:
Bump steer kit (mine went at SOWs and wiped out my rear SRC damper reservoir)
Diff failure (after ~180k, took a while but it went, fortunately while I was cooling off in the paddock).
Also replace your bearings once you start hearing the squeak/squeak/squeak...
I've been tracking this chassis since '00 and frequently visit the dirt.
Joined: Dec 2007
Posts: 4,525
Likes: 1
From: Savannah, GA, USA
Fail = broken spot welds on the A-arm's upper mounting bracket and separation of the bracket from the body.
On mine it "peeled" away, and was still attached somewhat, on others it's a full separation.
It'll feel like your alignment is off + klunking noises when you turn the steering wheel.
The fix is to remove the a-arm and have the mount bracket welded solidly to the body.
I'll snap some pics when I swap pads this week...
On mine it "peeled" away, and was still attached somewhat, on others it's a full separation.
It'll feel like your alignment is off + klunking noises when you turn the steering wheel.
The fix is to remove the a-arm and have the mount bracket welded solidly to the body.
I'll snap some pics when I swap pads this week...
Registered User
Joined: Jul 2007
Posts: 569
Likes: 1
From: Twin Cities
Originally Posted by Dipstick' timestamp='1305724458' post='20587765
Fail = broken spot welds on the A-arm's upper mounting bracket and separation of the bracket from the body.
On mine it "peeled" away, and was still attached somewhat, on others it's a full separation.
It'll feel like your alignment is off + klunking noises when you turn the steering wheel.
The fix is to remove the a-arm and have the mount bracket welded solidly to the body.
I'll snap some pics when I swap pads this week...
On mine it "peeled" away, and was still attached somewhat, on others it's a full separation.
It'll feel like your alignment is off + klunking noises when you turn the steering wheel.
The fix is to remove the a-arm and have the mount bracket welded solidly to the body.
I'll snap some pics when I swap pads this week...
Edit: This is what they had: http://www.summitracing.com/parts/DNT-DF701/
Joined: Apr 2005
Posts: 700
Likes: 1
From: Martinez, CA
Watch out for valve retainers failing over time and damage from previous overrevs. I understand this is an AP1 issue, not AP2.
marks_lude, not to thread jack but do you think the rotary stripping tool would be effective on removing Dynamat? Maybe pull up the metal backing portion then clean up with the tool?
marks_lude, not to thread jack but do you think the rotary stripping tool would be effective on removing Dynamat? Maybe pull up the metal backing portion then clean up with the tool?
Joined: May 2004
Posts: 1,531
Likes: 3
From: Tucson
Here are some photos of the front A-arm showing the start of the brackets pulling away as well as the recovery welds. This is an autocross car that was running Kumho 710 DOT race tires. The effect happens under hard repeated braking. Of course with race tires they took more force than would be generated with street tires. I recommend using a razor to score the rubberized coating to form the boundary where you want it removed and then using a scraper to get it off.
A-arm photos
A-arm photos
Former Moderator
Joined: Jul 2005
Posts: 4,634
Likes: 28
From: West Virginia
A rotary steel brush (Home Depot $10) on a drill works well for removing the undercoating to prep for welding. You've got to get into the cracks and get it all out to keep from contaminating your welds. If the bracket has pulled away it must be put back into contact--you can't weld air.