a yellow MINI at an autocross in Louisville this weekend broke a lower a arm on the rear on his second run. Stock MC on r compounds, on a fairly new car.

Is this something that people have been experiencing, or was it a fluke?

 

No it is not common, but it happens. The lateral links (not A arms) are only strong in their intended motion range. If they are hit or used to tie down the car while towing they acan be damaged and fail.

 

This is not the first control arm that I have heard of failing under a large load. If you do a search you will find quite a few threads discussing it. Is it an epidemic? I don't think so. Is it something that you should be worried about? Do you regularly push the car to the edge? What is your tolerance for a failure? I have had no issues with my control arms, but will be replacing them shortly with the Altas as preventative maintenance. Last thing I want is a disabled car on the AutoX track or Dragon. Piece of mind for me.

 

I am now carrying an extra stock part with me just in case. It would be a quick fix on the road, but damn hard to fix at the Dragon without the part in the boot.

 

Don't you have to drop the subframe to get to the upper mounting bolt to change out the arm? The bolt in question is the one at the right of the Alta control arm in the picture:

 

Nope, no need to remove anything for access if you have the right combination of tools. I changed mine out (to install H-Sports) back in early 2003 (got one of the first sets) without using anything exotic and the rear of the car up on jackstands.

I can't tell you exactly which wrenches/ratchets/sockets I used since I haven't had a reason to take them out since then.

Scott
90SM

 

Hiya!

That was my car that broke. I am the yellow mini in Louisville.

My car is a 2002 and it had the original (weaker design) lower wishbone arms on it. I figure one letting go after 4 years isn't that bad. I replaced both with OEM parts that have been updated slightly (same model number, little different design). The guy who works on my car (Drew Doukas, Evo Autosport) says it is a fairly common failure on high grip surfaces with race tires (like at Peru tours, etc). I was on grippy asphalt/concrete with Hoosiers so that pretty much fits the equation. Looking at it, I dont think it was a sudden failure, but slow degridation over time that finally let go. I know that I will now add these to my preventive maintenance inspections every couple months.

I would upgrade to aftermarket pieces if I could, but staying within the HS allowances, more OEM parts for me.

 

Oh, here is a cool pic of the action as it was breaking (or soon after)

 

That's a great picture.

 

I have one extra stock control arm. Free for the shipping!

PM me if interested.

Matt

 

Wow. Talk about tip-toeing around the corner. That's incredible the photographer had a lens trained on you as it was happeneing.