Control Arms and Metal Fatigue

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23crate

Well-known member
Joined
Sep 26, 2014
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1,362
Location
new zealand
heres a little issue i found today .. for a minute i was disbelieving so i poked the thing .. ...

more disturbing is the arm is on the drivers side, and i had been testing brake balance not to long before finding this - lucky we live in a quiet no exit valley

3 trips to my local garage - they hadnt picked this up .. each trip is a round trip of 16 miles - most of that is good for 50-60mph...

i suspect this has been like this for a while.. - the car had a wheel alignment start of July last year ...

pays to check stuff yourself i reckon....
 

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That kind of failure makes ya get weak kneed.
Being as it had an alignment, it possibly could of happened after that.
 
.. a Stude site ,, somebody came up with this... a very good point and maybe applicable to other brands of cool cars ...

"You should check whether the bushing is moving on the threaded pin. My guess is it has seized from lack of lubrication. If the control arm cannot move up and down, it is going to flex, fatigue and eventually crack. Sometimes to can be really hard to get those outer bushings to take grease.""

sounds very feasible to me ...
 
.. a Stude site ,, somebody came up with this... a very good point and maybe applicable to other brands of cool cars ...

"You should check whether the bushing is moving on the threaded pin. My guess is it has seized from lack of lubrication. If the control arm cannot move up and down, it is going to flex, fatigue and eventually crack. Sometimes to can be really hard to get those outer bushings to take grease.""

sounds very feasible to me ...

I was going to comment something similar the other day but didn't have time.

If everything is moving as designed, you shouldn't have any significant forces in that area of the control arm. As soon as you get wear or lack of lubrication that can cause the stress flow in the part to change and getting bending or other stresses in areas that previously experienced negligible stress. If the control arm one side is cracked, it's probably a good idea to replace the control arms on both sides.
 
I was going to comment something similar the other day but didn't have time.

If everything is moving as designed, you shouldn't have any significant forces in that area of the control arm. As soon as you get wear or lack of lubrication that can cause the stress flow in the part to change and getting bending or other stresses in areas that previously experienced negligible stress. If the control arm one side is cracked, it's probably a good idea to replace the control arms on both sides.

yep indeed this has crossed my mind.. i thinkim partially responsible as i have greased anything - although i dont think it wouldve saved tharm ,

the opposite side looks as if it was replaced. brake pedal was super sticky so have stripped cleaned and regreased the pivot works great ..

i suspect the last owner really just didnt know or care that Studes need their nipple greased every 1000miles .. i got a new tube of grease and 26 nipples waiting for fun
 
yep indeed this has crossed my mind.. i thinkim partially responsible as i have greased anything - although i dont think it wouldve saved tharm ,

the opposite side looks as if it was replaced. brake pedal was super sticky so have stripped cleaned and regreased the pivot works great ..

i suspect the last owner really just didnt know or care that Studes need their nipple greased every 1000miles .. i got a new tube of grease and 26 nipples waiting for fun

Unless you've put tons of miles on the car, it was more likely a result of years of insufficient maintenance from previous owners.
 

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