Can lubricant actually damage spring steel?
Can lubricant actually damage spring steel?
(OP)
From a couple of automotive replacement spring websites,
If this is in fact true, can anyone explain the chemistry?
jack vines
Quote:
Grease has an adverse reaction to spring steel which causes the steel to degrade and weaken the spring, so we do not recommend using grease/graphite between the leaves.
If this is in fact true, can anyone explain the chemistry?
jack vines





RE: Can lubricant actually damage spring steel?
RE: Can lubricant actually damage spring steel?
RE: Can lubricant actually damage spring steel?
I'll ask in the workshop, we've been building leaf spring cars for 50 years or more, someone will know.
Cheers
Greg Locock
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RE: Can lubricant actually damage spring steel?
Eaton makes a lot of springs for OEMs and the aftermarket, but is it likely a large truck/heavy equipment OEM would put a SAE5160 spring on equipment where lubricant leaks are a fact of life, knowing it would result in deterioration?
jack vines
RE: Can lubricant actually damage spring steel?
Grease is applied routinely to all sorts of things made out of steel. In much more demanding environments than between leafs of a leaf spring stack.
Grease is routinely smeared on steel things that shouldn't rust in storage or shipping.
So I'm inclined to call BS.
RE: Can lubricant actually damage spring steel?
And grease and ATF are similar in that they are lubricants, but other than that, quite different; different additives to petroleum products so that annecdote sounds like hokum.
So unless this is a case of SCC due to chlorides, I'm with the BS call.
rmw
RE: Can lubricant actually damage spring steel?
I call BS.
Regards
Pat
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RE: Can lubricant actually damage spring steel?
Does this question possibly arise from the reduced internal frictional damping of a greased leafpack? To illustrate my ignorance, does a standing wave ever occur in a leaf spring if excited in some particular manner? Even if the center (or whatever point) is well damped by a separate damper ("shock absorber")? I just don't know...
RE: Can lubricant actually damage spring steel?
Regards
Pat
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RE: Can lubricant actually damage spring steel?
page 83 here makes it pretty clear how badly rusted steel is impaired.
http://www.timken.com/en-us/Knowledge/engineers/ha...
RE: Can lubricant actually damage spring steel?
RE: Can lubricant actually damage spring steel?
RE: Can lubricant actually damage spring steel?
Mike Halloran
Pembroke Pines, FL, USA
RE: Can lubricant actually damage spring steel?
RE: Can lubricant actually damage spring steel?
I guess if a metal was used it could dissociate and form a galvanic cell with the iron or more likely some other component of the steel alloy, however the reactive metal would be the sacrificial one and this (having the metal in the grease being the sacrificial one) would certainly seem to be an objective when formulating grease. Anyway, from my experience, grease protects rather than corrodes metals.
Regards
Pat
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RE: Can lubricant actually damage spring steel?
The additives I mentioned are non-reactive with steels, as they would have to be in order not to corrode the metal surfaces. In other words, they would be no good if they reacted with the metal and would be anathema as a lubricant additive.
RE: Can lubricant actually damage spring steel?
RE: Can lubricant actually damage spring steel?
There must be a mostly mechanical answer. Lubricants decrease the friction, maybe the spring operates at a lower temperature and fatigue characteristics are worse. Maybe it is more prone to "sag" when it sits at rest because interleaf friction is much lower. I'd buy that actually.
"It just doesn't work and we don't know why" can be explained by black magic, or 99% of the population will also accept "an adverse chemical reaction" because they don't know the difference between the two.
A lot of people know that a lot of things "just don't work" and for most, "that's how everyone does it" is a good enough explanation. For engineers it is not.
But everyone knows mechanical engineers hate chemistry, so points for effort on this one.
RE: Can lubricant actually damage spring steel?
RE: Can lubricant actually damage spring steel?
RE: Can lubricant actually damage spring steel?
RE: Can lubricant actually damage spring steel?
the only way the grease could effect the 5160 steel if some contamination was to be found in the grease.
thus causing some type chemical reaction.
Example would be faulty manufacturing of the grease it self, but I really don't see that as a possibility.
Mfgenggear
RE: Can lubricant actually damage spring steel?
RE: Can lubricant actually damage spring steel?
I must have easily achieved 300000 miles, :>)
any way it's possible but I don't believe it would. :>)
Mfgenggear
RE: Can lubricant actually damage spring steel?
RE: Can lubricant actually damage spring steel?
But for it to happen on the scale required to cause a part to prematurely fail is highly unlikely.
Ron Volmershausen
Brunkerville Engineering
Newcastle Australia
http://www.aussieweb.com.au/email.aspx?id=1194181
RE: Can lubricant actually damage spring steel?
Maui
www.EngineeringMetallurgy.com
RE: Can lubricant actually damage spring steel?
Fair and correct. But this is a purely physical phenomenon.
The original claim is that "Grease has an adverse reaction to spring steel which causes the steel to degrade and weaken the spring" which appears to have no basis in chemistry.
RE: Can lubricant actually damage spring steel?
is, to the best of my knowledge, patently false. It appears that someone drew an incorrect correlation between SAE 5160 leaf spring failures and the observation that grease was being used to lubricate them. The additional suggestion to
should make the reader question why the power steering unit would be leaking in the first place. Likely because the truck has significant milage on it. This number of miles creates wear and tear on the shocks, which no longer work as effectively as they should. And for lubed springs, these worn shocks can create the issue.
It appears that the faulty cause and effect line of reasoning for these observations was never actually confirmed, which is why they persist, even if they're are wrong.
Maui
www.EngineeringMetallurgy.com
RE: Can lubricant actually damage spring steel?
RE: Can lubricant actually damage spring steel?
rmw
RE: Can lubricant actually damage spring steel?
Maui
www.EngineeringMetallurgy.com
RE: Can lubricant actually damage spring steel?
Regards
Pat
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RE: Can lubricant actually damage spring steel?
You said "It appears that the faulty cause and effect line of reasoning for these observations .."
My UFO tale was intended to be another "example" of faulty cause and effect reasoning. I figured it would be less controversial than the many examples distributed as news every day.
RE: Can lubricant actually damage spring steel?
Maui
www.EngineeringMetallurgy.com
RE: Can lubricant actually damage spring steel?
Or aliens. [3eyes] Blame the aliens.
RE: Can lubricant actually damage spring steel?
But my front springs have been replaced with current production Eaton springs, and the left front is right under my leaky manual steering box. 90 wt gear lube passes thru the box like water, keeps the leaves soaking wet. No sag or lean yet, but the front shock is inadequate with no friction to help.
Here's what comes from failure to lubricate on schedule... my rear leaves
RE: Can lubricant actually damage spring steel?
RE: Can lubricant actually damage spring steel?
I went to research coil spring failure today and found this article from the british Automobile Association
Coil Spring Failure Season
Their empirical evidence suggests that road salt induced corrosion is the source of spring steel failure, perhaps some materials engineers can confirm or invalidate that claim, but they state:
Hydrogen embrittlement
Electrolytic action between the salt solution, formed by road salting, and the iron in the spring generates free hydrogen atoms which enter the steel and can cause microscopic cracking. Cracks propagate and combine, ultimately leading to failure of the spring.
I would also note that most coil springs are coated, plated, or painted in some way to reduce or eliminate corrosion.
And if I am not mistaken greases are hydrophobic - meaning they would repel salty water from the road and keep it away from the springs.
Conversely if the springs grind against each other with some grit or dirt and grease it may have an abrasive effect like lapping compound.
I believe this recommendation is made with the goal of increasing spring sales but I welcome insights from materials engineers on this report from the AA. I think the question is of a materials nature, and not a mechanical one.
-ATE
RE: Can lubricant actually damage spring steel?