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The_Hammer

To whoever conceived the abomination known as Active Fuel Management....

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I hope you choke on a bag of d**ks! icon_smile_angry.gif.08af1d9fb7c9143638e

Had yet ANOTHER afm lifter take a dump tonight on the wife's 2009 GMC Sierra. I'm converting it to regular lifters and pulling all of the AFM garbage off, enough is enough. I need a new cam ($93), lifters ($113), valley plate ($42), and the ECM reprogrammed ($50). I'm going to pull the electric fans, radiator and A/C condenser to get the cam out. Thank you GM for implementing such a failure prone pos system on an otherwise reliable vehicle icon_smile_angry.gif.08af1d9fb7c9143638e

Edited by The_Hammer

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27 minutes ago, CTcummins24V said:

My 2013 silverado has it. I just put it in manual mode and shift with my thumb and AFM doesn't "activate", unless you hit 6th gear

I have the AFM disabled on this truck and a lifter still failed. The only thing I can think of is that the retention pin inside the lifter broke. 

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Why would they need to redesign the assembly for firing off of 4 cylinders instead of all 8? Are the rockers and pushrods different too? I didn't grow up around small blocks so I'm at a loss for all this. Top pic as an AFM lifter for my truck and the bottom is non AFM. 

12619820_Primary.jpg

HL128_Primary.jpg

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@CTcummins24V The camshaft lobes are different for the AFM lifters and will not work with solid lifters. The AFM lifters are taller and if you replace them with solid lifters you will only reach about 25% compression on those cylinders.

@Mopar1973Man The lifters fail by compressing in on themselves and sticking due to a buildup of varnish inside the lifters. There is a spring loaded metal pin running horizontally through the AFM lifters that is released via oil pressure. With afm disabled the pin will never be released and the lifter will not compress. However, if the pin breaks the lifter will compress and if there is a build up of varnish inside the lifter it will stick.

@IBMobileI'm using torque to yield bolts. I'm not doing anything but replacing the cam and lifters, lifter trays, valley plate, new head gaskets, and reprogramming the ECM. Money is tight so I have to do the bare minimum to get it back up and running right.

Edited by The_Hammer

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31 minutes ago, The_Hammer said:

The lifters fail by compressing in on themselves and sticking due to a buildup of varnish inside the lifters. There is a spring loaded metal pin running horizontally through the AFM lifters that is released via oil pressure. With afm disabled the pin will never be released and the lifter will not compress. However, if the pin breaks the lifter will compress and if there is a build up of varnish inside the lifter it will stick.

:think:

Something to read...

http://www.machinerylubrication.com/Read/59/oil-analysis-varnish

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Since I needed my truck and car pooling wasn't going to work my wife continued to drive her truck. Well, the lifter ended up banging itself free and everything is fine again, thank you God! 

I contacted Range Technologies about the AFM disablers intermittent function issue and was told it needed an update. So, I'll be plugging it in to the laptop to do just that. 

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