Jump to content

IGNORED

Time to Speculate : Coil Spring Breakage


zKars

Recommended Posts

Ok, todays challenge is to help me understand how the following broken coil spring situation may have happended. 

First, a picture is worth a thousand words.  1969 510 rear springs. 

First two are left and right springs “pieces” on the floor after extraction. Third is the left rear as I saw it initially. 

 

EB45FE9D-12F4-454B-97C3-7321DFCF93EE.jpeg

7DFC1D05-B113-47CE-9E59-3F58E0A45862.jpeg

CD02F586-EA82-4D16-B9F3-0CAD7CFF2355.jpeg

  • Sad 1
Link to comment
Share on other sites


First clue is the vehicle mileage

50.000 miles.

Second clue is the condition of spring pockets. Both are filled with very hard packed, very dry mud. I had to literally excavate the mud by chipping and digging with pointy tools to extract the broken ring segments.

Third is a usage history. 1969-1980 used by a rural north BC dwelling mother of three. Car was then parked after a low speed front end accident. The car was moved around very sporadically over the remainder of its life.  

There is no admitted history of extreme driving, though you can just imagine. No other part of the car suggests any General Lee type stunts. 

Forth is the definite lack of rust in the spring pocket metal or surrounding area. Not like the springs were immersed in water for forty years nor is the spring material shows more than minor rust damage.

Edited by zKars
Link to comment
Share on other sites

Sp the question is, under what conditions would the springs break into so many pieces?

The first break is above the packed mud. The remainder were all buried in the terra-very-firma

Link to comment
Share on other sites

They kept driving it after the first break! The spring kept self deteriating. Wouldn’t want to install a new spring when you still have 2/3 of a spring left! Those 510’s are tough little bitches!!!!👍

Edited by Diseazd
  • Agree 1
  • Haha 1
Link to comment
Share on other sites

I think the packed mud is a clue that the car spent time on a dirt road.  The mud likely packed between the coils as well as below them and caused coil bind when subjected to full jounce travel over the rough dirt road.  The owner likely overloaded the car often with kids and stuff in the trunk making the situation worse.  Once a coil broke, the car would sit lower and when not repaired, the next weakest spot failed from being subjected to unusual forces from the spring position.  The rust might be minor, but it did likely factor in a bit.

  • Like 1
  • Agree 1
Link to comment
Share on other sites

I'm inclined to agree with Jeff G 78.  If the mud packed at the bottom of the spring, then the free portion would be carrying the entire load at that corner and it would eventually cause flex fatigue.  I'll bet the second break came soon after the first one.  Poor little spring.

Link to comment
Share on other sites

Lots of clues here.

Having (used to) lived on a dirt road for 20 years, I've seen ruts and potholes that would swallow my wife's MX-5.  Literally, she would have to detour around certain roads after hard rains - this in Loudoun County, VA of all places.

Maybe our mom with the 510 had no options for detour, was late getting the kids to school, and had to hurry to meet her lover. "Springs? We don't need no stinkin' springs."

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

By using this site, you agree to our Privacy Policy and Guidelines. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.