Broke my Kenny Brown rear lower control arms on road course. Second time. First time weld failed and was able to rear. Second one other side complete catastrophic failure. Time to change back to stock lowers
WTB 1999-2004 rear lower control arms
- Thread starter NotsoFastFreddie
- Start date
2002
35k 1999 Ford Mustang Cobra. No racing just High Performance road course track days. 4-5 a year, 20+ years
Driver side weld failed but I caught it early and was able to weld it back up. This passed weekend the passenger side completely failed, not at weld which is even more of a concern. I do pretty detailed pre and post track day inspection and no signs, prior to failure.
I am not sure if my stock aluminum lowers will bolt up to KB IRS cradle but I am considering.
35k 1999 Ford Mustang Cobra. No racing just High Performance road course track days. 4-5 a year, 20+ years
Driver side weld failed but I caught it early and was able to weld it back up. This passed weekend the passenger side completely failed, not at weld which is even more of a concern. I do pretty detailed pre and post track day inspection and no signs, prior to failure.
I am not sure if my stock aluminum lowers will bolt up to KB IRS cradle but I am considering.
That is insane. I don't remember when KB made the design changes so those could be the old design.
I'd be curious to know if you can still use the stock lower arm because as you know KB cuts the mounts off and weld them into a slightly different location.
However one would think if the KB arms fit a stock IRS then it wouldn't matter.
Got any pictures?
That looks like it rusted out.
I pulled it off last night and welded it back up. Its back on the trailer heading over to my alignment shop. If he confirms in spec Ill pull off both sides and add a gusset to beef them up. I got 20 years out of them so what the heck. Sadly I inspect my car pre and post track day events and didnt see any hint of rust or fatigue on welds. Powder coat hid it well. Light surface rust may have added to the fatigue and failure
Good news is I felt it let go and back off before it failed completely
Good news is I felt it let go and back off before it failed completely
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KB said you cant use stock Cobra lowers with their modified IRS Cradle
I have read about failing KB lower control arms in the forums for years now, if not decades. If I were in your shoes, I’d remove one and see if a I could find a good fabricator to make a more robust and higher quality set out of better materials. And then monitor frequently 
After alignment check, if good I’ll pull back off, both sides and add gussets to the thin tabs
I’ll post pictures when completed
I’ll post pictures when completed
Well good news. My welds were perfect and alignment shop said my numbers were spot on. Ill be adding gussets to build a little more strength into the piece. Should get another 20 years out of them!
Now deciding which cross axis bushings to replace my shot ones with; SPC or MM
Any experience with either?
Now deciding which cross axis bushings to replace my shot ones with; SPC or MM
Any experience with either?
Going to go with MM bits thru Full Tilt!
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