Coil Spring ding

[alpinekid]

I have started to work on my 1992 E350 bus with almost 200,000 miles.
I bought this bus at action over a year ago and haven’t really driven it much. It came directly from one of our schools in CA and it seems like it has been given really good care. No sign of any cheating or short changing our students on maintenance. The maintenance was done directly by our school and not some external corporation. I’ve found a lot of new looking parts, brake lines, AC unit, hoses etc. All with factory ford numbers,so I’m feeling good about the work.

I’m going over the thing just the same, changing all the fluids etc.

During my inspection I notices something on one of the front coil springs that gives me concern. See image attached.

There looks to be some kind of ding on the spring. I first thought it was fretting corrosion but after I got a good look at it, it looks like some kind of grind or gouge. The only thing close to it is the shock. I wonder if at sometime the shock failed and dinged the spring. Or is this some kind of “tuning” of the spring, I’ve never heard of; Just hoping it will be OK

I can not see an sign of a crack or pitting. After cleaning the spring it looks good otherwise. There is some yellow paint on the spring. It looks like it might be over-spray from when the bus was painted yellow; its only on the outside edge towards the wheel; so I’m thinking these might be original springs. This doesn’t really give any clues about when the ding happened or how.

Has anyone seen anything like this?

Does it seem serious?

How hard is it to change the springs?

[lqdchkn]

Looks to me like someone was in there with a grinder and hit the spring while grinding.

Seeing as how the shock is right there. I'd bet that at some point in the bus's life that a mechanic stripped the upper threads/nut on the shock trying to replace, having to end up cutting it out and made some contact with the spring in the process.

IMO it doesnt look bad enough to worry about.

[Danjo]

I’m thinking it’s damage caused by compression tools.

[alpinekid]

thanks, I can believe that. The nut on top of the shock is almost impossible to get to. You have to take out everything above it, battery, coolant overflow and wheel well sheet metal. Its easy to see someone just cutting the shock and hitting the spring.

I just want to be sure I'm not looking for reason to ignore a hard to fix problem.

I think auto engineers should be required to repair a vehicle before their designs are release.

[Danjo]

IDK. The thing is, a spring won’t warn before failure. Will it fail? I think you’ll need to find someone with more experience than me.

[o1marc]

20 years of racing experience. Nothing on that spring concerns me. I've actually done an indepth test on heating and powder coating automotive springs. Make no noticeable difference.

[alpinekid]

When I look at the suspension system, it looks like even if the spring fails the front end does not come apart. The body has a bumper that will hit the front beam. total drop is only about 2-3 inches. The ride goes to hell but its still sorta drive-able if the spring parts don't impact the tire. Not something I want but depending on speed it would be survivable. I don't intend to do any off-roading just some well traveled dirt roads in the desert.
Other have also seen no issues so I'm feeling better but it will take some time and close observation to feel comfortable.

[banman]

That gouge (and I agree with the slip of a grinder being the likely cause) is deep enough to cause a concentration of stress and therefore it will fail there from fatigue -- I can't tell you when... only that it will...

When it does break, as stated, the suspension will only drop a little...

However, the jagged edges of broken spring will not be contained and may contact the tire. I can't tell from your pics how close your wheels are to the springs. I can tell you what happens if the jagged edge contacts the tire...

An E350's only a 1ton truck so any parts store will loan you a spring compressor if needed.

Or it could be that just by jacking up the bus from the frame you can relieve all the compression from the spring.

Been years since I've done this but I used heavy chain to secure the spring to the frame in case the spring tried to pop out -- you DON'T want a compressed spring jumping through your chest!
Read up on how to work on your specific chasiss configuration.