Check Trailing Arm for Rot
#1
Tech Contributor
Thread Starter
Check Trailing Arm for Rot
I posted this info on FB yesterday, some have seen it, maybe some have not. Since many guys do their own work, this should help. I expect a qualified rebuilder would know this already.
If you check your TA to rebuild them, look closely at them. Look at the end overlaps and pinch the metal inside the large opening. The overlaps should be flat and crisp, no expanding or holes. If you feel a bulge in the pocket the arm is no good. They rot from the inside out. This arm would have looked decent once painted but it would have been decent junk. If you buy arms, bare or assembled, check them. Look at pictures before you buy used arms. If no pictures are sent, good luck. I cut this one in half to show how much the rust expanded within the seam.
If you check your TA to rebuild them, look closely at them. Look at the end overlaps and pinch the metal inside the large opening. The overlaps should be flat and crisp, no expanding or holes. If you feel a bulge in the pocket the arm is no good. They rot from the inside out. This arm would have looked decent once painted but it would have been decent junk. If you buy arms, bare or assembled, check them. Look at pictures before you buy used arms. If no pictures are sent, good luck. I cut this one in half to show how much the rust expanded within the seam.
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#4
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My original ones were that bad or perhaps worse. I didn't even think of rebuilding them.
#5
Old Fart Pilot
#6
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#7
Instructor
I'm in the process of rebuilding my rear drivetrain and suspension. I have a similar situation with my control arms. I had just read this post so was looking out for it. I poked around with a small pic, expecting there to be soft rust inside, but it was firm like there was a weld or something. I also noticed the separation on many of the cars that I looked at to purchase. At the time I thought it was due to the material being too weak to handle the forces of the spring. Is it normal to have a little bit of separation between the overlapping pieces of metal? In general the trailing arms are in fairly good shape with just minimal spot surface rusting in a few places.
#8
Tech Contributor
Thread Starter
Separation is rust, small or large it has started. Some will attempt to cut it out or treat it but if you're going through the car, buy new USA made arms and be done with it.
#9
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I did mine about 10 years ago, give or take. As I recall, a pair of bare arms were fairly affordable, and I'm poor.
No reason at all not to purchase new quality arms if there is even the slightest doubt.
No reason at all not to purchase new quality arms if there is even the slightest doubt.
#10
Instructor
Yes, I came to the same conclusion. As much as it hurts to spend a bunch of money this time of year, I'm going to purchase some new US made trailing arms. Merry Christmas to me.