[Novanutcase]

Will running steel rod ends into an alumninum UCA be a problem? Someone told me that running steel rod ends threaded into an aluminum UCA will wear out the aluminum threads. Is this a concern I need to be worried about?



John

[brian0605]

I haven't heard that before. Now as you well know the aluminum isn't as strong as the steel and you might possibly run into corrosion problems from the dissimillar metals. I don't think that will be that big of an issue. I would see about installing heli coils into the holes and then they would be plenty strong enough. Just a thought.Brian

[Novanutcase]

Thanks Brian! Great Idea on the Heli coils. I'm a little concerned as this is a critical part of the car that gets a lot of stresses thrown at it.

[powerrodsmike]

Heli coils are routinely installed in aluminum parts that see alot of stress. Many times the designer will spec them when the part is designed.

I remember putting a ton of those thing in the robotics stuff we were building at the machine shop I worked at.



There are several other types of inserts. One is called a "timesert". Similar to a helicoil, but solid bodied. The guys that use them never use a helicoil again.
Alot of the aftermarket harley stuff has them in cases , head studs, spark plug threads, etc.

http://www.timesert.com/

There is one called Keensert, that one is solid bodied also but has tangs that you pound in to the part after installation, so it locks in.

http://www.alcoa.com/global/en/produ...sp?prod_id=473

Later, mikey

[joe_padavano]

Just remember that any thread insert will require drilling and tapping a larger hole in the aluminum, which reduces the thickness of the aluminum and results in a weaker part. I don't know how thick these control arms are, but figure out how thin the aluminum will be when you drill and tap for the thread insert. With the configuration you have, there is a stress riser at that thin section that can cause the aluminum to split right at the insert. Also, helicoils are the thinnest insert and will result in the least strength reduction in the aluminum.

[powerrodsmike]

Originally Posted by joe_padavano

Just remember that any thread insert will require drilling and tapping a larger hole in the aluminum, which reduces the thickness of the aluminum and results in a weaker part. I don't know how thick these control arms are, but figure out how thin the aluminum will be when you drill and tap for the thread insert. With the configuration you have, there is a stress riser at that thin section that can cause the aluminum to split right at the insert. Also, helicoils are the thinnest insert and will result in the least strength reduction in the aluminum.

Excellent points.
Helicoils are also the hardest to install correctly. It is best to use a long helicoil in a deep hole, than to use several short ones.

Later, mikey