Lifter Problem
1st Gear
Joined: Nov 2025
Posts: 1
Likes: 0
From: Staunton, IL
Hello! New to the forum. But I recently watched a video wherein the guy claimed that the AFM on the manual transmission only activates if you select "Economy" mode. He claimed the AFM will not activate in Tour, or Sport, or Track modes. I had a 2014 Chevy truck 5.3 motor and it stuck a lifter while it was still under warranty. I realize its not the same engine as the C7 - but I was advised by a savvy local mechanic to get the Range OBD plug-in and stop the AFM from activating. I saw no long term damage from the event - but the truck was at the GM dealer for about a month waiting on a GM rep to show up to authorize replacing the lifters.
Stick Shift Enthusiast
Joined: Oct 2005
Posts: 7,489
Likes: 2,671
From: Troy & Dearborn, Michigan
I understand the preference for precise terminology. However, within the context of a GM AFM system, the term 'lifter spring' is universally recognized in the automotive community to mean the internal spring responsible for collapsing the lifter. While 'plunger spring' is the more technically accurate name, using 'lifter spring' efficiently identifies the failed component in question, and most English language speakers, in this context, will understand it’s not a reference to a valve spring, nor to a conventional solid lifter:
So, what would you call this component, and why do you oppose the colloquialism—and widely accepted terminology—of 'lifter spring'?
So, what would you call this component, and why do you oppose the colloquialism—and widely accepted terminology—of 'lifter spring'?
Stick Shift Enthusiast
Joined: Oct 2005
Posts: 7,489
Likes: 2,671
From: Troy & Dearborn, Michigan
Elgin Industries is a leading expert in GM valvetrains. Here’s a quote from them.
”
The lifter spring will stay compressed to prevent the pistons from contacting the valves. This lifter design is a huge improvement over the old/troublesome design of the active fuel management lifters!”
You can find the quote on this page.
https://northernautoparts.com/afm-li...-00Xe4K6erCW4W
Let me know how it goes when you tell them you know more than they do and they’re using the wrong words that matter.
”
The lifter spring will stay compressed to prevent the pistons from contacting the valves. This lifter design is a huge improvement over the old/troublesome design of the active fuel management lifters!”
You can find the quote on this page.
https://northernautoparts.com/afm-li...-00Xe4K6erCW4W
Let me know how it goes when you tell them you know more than they do and they’re using the wrong words that matter.
Stick Shift Enthusiast
Joined: Oct 2005
Posts: 7,489
Likes: 2,671
From: Troy & Dearborn, Michigan
Hello! New to the forum. But I recently watched a video wherein the guy claimed that the AFM on the manual transmission only activates if you select "Economy" mode. He claimed the AFM will not activate in Tour, or Sport, or Track modes. I had a 2014 Chevy truck 5.3 motor and it stuck a lifter while it was still under warranty. I realize its not the same engine as the C7 - but I was advised by a savvy local mechanic to get the Range OBD plug-in and stop the AFM from activating. I saw no long term damage from the event - but the truck was at the GM dealer for about a month waiting on a GM rep to show up to authorize replacing the lifters.
I'd avoid a range, it's a hack and frankly has other unknown side effects, if you want to disable it do it via an PCM/ECM tune where you "cal it off"
Team Owner
Joined: Jul 2004
Posts: 28,376
Likes: 3,260
From: Hartford WI
Stick Shift Enthusiast
Joined: Oct 2005
Posts: 7,489
Likes: 2,671
From: Troy & Dearborn, Michigan
Everywhere I've read they only refer to the whole part, and its called an AFM Lifter.
OEMs tend to not have "official" names for anything that doesn't have a customer addressable part number. Since they only catalog parts by a part number, that's the only thing that gets assigned a name. I put "official" in quotes as the service team assigns the names in the part catalog and sometimes you get some weird names. Especially for fasteners.
It's listed in the part catalog as:
Lifter Assembly, Vlv (Afm)
OEMs tend to not have "official" names for anything that doesn't have a customer addressable part number. Since they only catalog parts by a part number, that's the only thing that gets assigned a name. I put "official" in quotes as the service team assigns the names in the part catalog and sometimes you get some weird names. Especially for fasteners.
It's listed in the part catalog as:
Lifter Assembly, Vlv (Afm)
Last edited by LT1 Z51; Nov 9, 2025 at 11:01 AM. Reason: Found part catelog name
Team Owner
Joined: Jul 2004
Posts: 28,376
Likes: 3,260
From: Hartford WI
Everywhere I've read they only refer to the whole part, and its called an AFM Lifter.
OEMs tend to not have "official" names for anything that doesn't have a customer addressable part number. Since they only catalog parts by a part number, that's the only thing that gets assigned a name.
OEMs tend to not have "official" names for anything that doesn't have a customer addressable part number. Since they only catalog parts by a part number, that's the only thing that gets assigned a name.
Stick Shift Enthusiast
Joined: Oct 2005
Posts: 7,489
Likes: 2,671
From: Troy & Dearborn, Michigan
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
Melting Slicks
Joined: Feb 2018
Posts: 2,134
Likes: 1,022
From: North Texas
If the above is all true, I can easily see him misunderstanding exactually what the repair shop conveyed to him. Terminology and words you know how they work.
An Inexperienced owner that is not mechanically inclined would not know the difference between a valve spring or a lifter spring. Thus, possibly the confusion in his post of the problem. Did he really know and understand all the nuances? In this case I sincerely doubt it.
If it was truly a lifter spring the shop would have stated that he had a collapsed AFM lifter or better, a broken AFM lifter and the unit would need to be replaced, and maybe more parts. I don't believe that the shop would have gone into such a technical description of the issue, especially to just to your every day, non-mechanical owner.
In the everyday world a shop would have reported to the owner that the car had a bad AFM lifter or a broken valve spring. These are the terms that the owner would have had a better chance of understanding.
Racer
Joined: Jul 2015
Posts: 404
Likes: 99
From: Chicago IL
St. Jude Donor '16
The only confusion in this thread is a handful of members that can’t admit error in unfamiliarity with industry standards terms and colloquialisms.
Again, while the official GM name for the component is a “plunger spring”, the more common term for the metal compressible component of an AFM lifter is “lifter spring”. Whereas Elgin Industries is an OEM manufacturer for GM as well as others, to cast them as an aftermarket company disparages their expertise in the automotive industry.
While a repair shop advising a failure of an AFM lifter is correct terminology, using the verbiage that a lifter spring failed is also correct and gives insight to the failed component of the specific lifter. Saying the “plunger spring” may be confusing to someone less mechanically inclined or unfamiliar with the components of an AFM lifter, the term “lifter spring” is an accurate description in the vernacular.
In short, colloquialisms exist to build social bonds, communicate efficiently, and reflect cultural identity.
Words matter and understanding synonyms and colloquialisms matter as well. YMMV
Again, while the official GM name for the component is a “plunger spring”, the more common term for the metal compressible component of an AFM lifter is “lifter spring”. Whereas Elgin Industries is an OEM manufacturer for GM as well as others, to cast them as an aftermarket company disparages their expertise in the automotive industry.
While a repair shop advising a failure of an AFM lifter is correct terminology, using the verbiage that a lifter spring failed is also correct and gives insight to the failed component of the specific lifter. Saying the “plunger spring” may be confusing to someone less mechanically inclined or unfamiliar with the components of an AFM lifter, the term “lifter spring” is an accurate description in the vernacular.
In short, colloquialisms exist to build social bonds, communicate efficiently, and reflect cultural identity.
Words matter and understanding synonyms and colloquialisms matter as well. YMMV
Stick Shift Enthusiast
Joined: Oct 2005
Posts: 7,489
Likes: 2,671
From: Troy & Dearborn, Michigan
The only confusion in this thread is a handful of members that can’t admit error in unfamiliarity with industry standards terms and colloquialisms.
Again, while the official GM name for the component is a “plunger spring”, the more common term for the metal compressible component of an AFM lifter is “lifter spring”. Whereas Elgin Industries is an OEM manufacturer for GM as well as others, to cast them as an aftermarket company disparages their expertise in the automotive industry.
While a repair shop advising a failure of an AFM lifter is correct terminology, using the verbiage that a lifter spring failed is also correct and gives insight to the failed component of the specific lifter. Saying the “plunger spring” may be confusing to someone less mechanically inclined or unfamiliar with the components of an AFM lifter, the term “lifter spring” is an accurate description in the vernacular.
In short, colloquialisms exist to build social bonds, communicate efficiently, and reflect cultural identity.
Words matter and understanding synonyms and colloquialisms matter as well. YMMV
Again, while the official GM name for the component is a “plunger spring”, the more common term for the metal compressible component of an AFM lifter is “lifter spring”. Whereas Elgin Industries is an OEM manufacturer for GM as well as others, to cast them as an aftermarket company disparages their expertise in the automotive industry.
While a repair shop advising a failure of an AFM lifter is correct terminology, using the verbiage that a lifter spring failed is also correct and gives insight to the failed component of the specific lifter. Saying the “plunger spring” may be confusing to someone less mechanically inclined or unfamiliar with the components of an AFM lifter, the term “lifter spring” is an accurate description in the vernacular.
In short, colloquialisms exist to build social bonds, communicate efficiently, and reflect cultural identity.
Words matter and understanding synonyms and colloquialisms matter as well. YMMV
Also many large aftermarket companies also make OEM components. Frequently what suppliers (as we call them at the OEM) use their own terminology which is different than the OEM. So it's an irrelevant statement as to what terms they use.
AFM is a GM specific term anyway. The generic term is DoD (Displacement on Demand). You want to call it a DoD Lifter Spring, go ahead, in my mind you're just being obstinate. I only got involved in this argument when I saw how it was going and felt like it needed some common sense. This also seems to be a foolish thought on my part. Can't fix.... well you know the rest.
Racer
Joined: Jul 2015
Posts: 404
Likes: 99
From: Chicago IL
St. Jude Donor '16
You're trying to win on a technicality after getting argued with by at least 4 other people. I'd say that speaks enough for its self.
Also many large aftermarket companies also make OEM components. Frequently what suppliers (as we call them at the OEM) use their own terminology which is different than the OEM. So it's an irrelevant statement as to what terms they use.
AFM is a GM specific term anyway. The generic term is DoD (Displacement on Demand). You want to call it a DoD Lifter Spring, go ahead, in my mind you're just being obstinate. I only got involved in this argument when I saw how it was going and felt like it needed some common sense. This also seems to be a foolish thought on my part. Can't fix.... well you know the rest.
Also many large aftermarket companies also make OEM components. Frequently what suppliers (as we call them at the OEM) use their own terminology which is different than the OEM. So it's an irrelevant statement as to what terms they use.
AFM is a GM specific term anyway. The generic term is DoD (Displacement on Demand). You want to call it a DoD Lifter Spring, go ahead, in my mind you're just being obstinate. I only got involved in this argument when I saw how it was going and felt like it needed some common sense. This also seems to be a foolish thought on my part. Can't fix.... well you know the rest.
My purpose here is to share accurate information that can help people. The evidence demonstrates that this term is in common use and effectively communicates the part's function. Insisting on a single 'correct' term, contrary to widespread practice, isn't particularly helpful for a community focused on sharing knowledge.
The idea that terminology you’re unfamiliar with or dislike makes that term incorrect or nonexistent, is childish at best, elitist worst and patently bizarre. I hope your kind of (you know what I mean) can be fixed. Language is constantly evolving, and your belief that the lexicon of knowledge need be blessed by you is also bizarre