Need to replace threaded pins on cross member.

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SunnySideUp
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Joined: Fri Apr 09, 2010 3:02 pm
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Need to replace threaded pins on cross member.

Post by SunnySideUp »

I took my Spider in for an alignment after getting the front end rebuilt. The alignment tech gave me some not-so-good news. One of the threaded pins on the cross member that mounts to the lower A-arm is becoming stripped. :cry: The cross member is not cracked and is in otherwise great condition. I received some great technical advice on what to replace the pin with in the form of a high-strength bolt. What I'd like to know is if anyone has a trick for popping out the old pin out without causing damage to the cross member. If at all possible, I'd like to do it without having to remove the cross member from the car. Any ideas?

Thanks!
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azruss
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Re: Need to replace threaded pins on cross member.

Post by azruss »

that is a bolt that is encased and tack welded to the cross member. no way to just replace it without some serious surgery. The malady is pretty common. It is usually the most inner portion of the thread that is stripped. The solution can be as easy as double nutting or adding a nut thick spacer and use the undamaged part of the thread, if there is any.
SunnySideUp
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Re: Need to replace threaded pins on cross member.

Post by SunnySideUp »

I think I'm looking at the "serious surgery" aspect. I can doubled-up the nut on the stud but it doesn't have enough bite to be effective.
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manoa matt
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Your car is a: 1978 Fiat 124 Spider 1800
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Re: Need to replace threaded pins on cross member.

Post by manoa matt »

I've had success restoring the threads with a thread die. Try to find one that has a hex shape so that you don't have to install it in the die holder. You can turn it with a wrench.
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seabeelt
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Your car is a: Fiat Spider - 1971 BS1
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Re: Need to replace threaded pins on cross member.

Post by seabeelt »

I used the all around dremel with a cut off wheel to get through the weld. Popped right out after that. You will however want to tack weld the new one in place.
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Michael and Deborah Williamson
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1971 Spider - Vesper -scrapped
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SunnySideUp
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Joined: Fri Apr 09, 2010 3:02 pm
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Re: Need to replace threaded pins on cross member.

Post by SunnySideUp »

Tried restoring the threads with a thread die. Made sure we had the right die and gave it a try. First couple of turns looked like it might be a success. But then we saw a curl of metal coming off. DAMN! Double-checked that we had the right die (we did - chased the threads on a "good" cross member pin and it was spot on). Good advice but the threads on the damaged pin were too far gone.

I sourced a set of 10.9 grade bolts and some 8.8 grade lock nuts to do the job (Bel-Metric in MA, easy to work with, fast shipping). Went 10.9 grade on the bolts to lessen the chance of them ever getting stripped again. I'll be setting up some shop time in a week or so and will take pics of the process -- going to try it with the cross member still installed on the Spider. Dremel and cut-off wheels ready and waiting. If it's a success I'll post the pics. If it's not successful you know that I'll be pulling that cross member.
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