brewtus

Somewhere in my research on this there is a TSB, Service Bulletin, or training material that states a mis-timed switching of DFM will likely result in bent pushrod. Therefore, it is a FACT that switching is ONE cause of pushrod/lifter failure. Eliminate the switching (i.e. Pulsar) and eliminate a cause. Yes the DFM lifters themselves can still by other causes fail but you have reduced the odds. Also, if you never energize solenoids supplying oil to the lifters through DFM (which is how I understand they work), they remain locked together and the pins/springs that travel in/out to lock them together are unlikely to fail. They function just like a traditional lifter all of the time, which have their own failure mechanisms.

My clear/rubberized overlay "skin" started to blister and come off of both remotes after only a couple of weeks. I just completely peeled the remaining rubber "skin" off of the base rubber top. I was worried the ink markings for the functions would come up with it or wear off quickly once the clear "skin" was gone, but after 10 months I am still good. It is pretty pathetic that a part of the truck you touch all the time and is constantly with you does this. Quality? Really?

Totally agree. Do that to all my vehicles, can't hurt but hope it IS the solution.

OK, I just kicked over 8k miles on my '21. I was purposely waiting until then to disable DFM to make sure I didn't have the lifter failure, as the original TSB was for 8k to replace both banks if they fail, now its up to 16k miles. Anyhow, I am thinking of the Pulsar LT to prevent the switching on/off all the time and minimize the opportunities for failure. Also, I can hear and slightly feel the DFM kicking in on highway even with stock exhaust. I want 10th gear back on the highway and not have to run L9! With all that said, has anyone had the Pulsar on to disable DFM for extended mileage WITHOUT lifter failures. Looking for some good evidence to support purchasing one other than just getting rid of the nuisance of it. Also, I did run an '07 up to 130k+ miles with AFM and no failures, and had a '16 with DFM that went to 28k OK, but want to keep this truck well into the 100k+ mileage range

What was your build date?

Right, it's the Pulsar LT from Range. I would have gotten one too if you didn't need to buy the Pulsar for $500 - all I need is the DFM deactivation since mine wasn't built with auto start/stop. Hard to justify the cost for just that. What's ironic is that for '22 models not build with DFM you get a $50 credit from GM. Heck, I would have PAID $50 to have it disabled!!!

You don't need to, but most likely will want a Range LT Pulsar to disable the DFM. That is currently what is holding me off on upgrading exhaust. I can definitely hear the DFM and feel very slight engine vibration when it activates on highway and smooth roads with stock exhaust. Will definitely be amplified by aftermarket exhaust. Go search youtube for videos, there are quite a few out there doing before/after comparisons with DFM active and not with aftermarket exhasust - Donslife and LMFScrew.

https://gm-techlink.com/wp-content/uploads/2022/05/TAC-Dealer-Monthly-Tips-and-New-Information-May-2022v3.pdf

FYI...Looks like they are taking the mileage up to 16k now....

Thanks for info. Yeah, I guess it wouldn't be out of the realm if the window sticker was wrong. Heck, they built my truck with the wrong back window (no tint at all!!), had to have that replaced. If you do find out for sure what "A" plant is I would like to know, just because of my curious nature if nothing else. Thanks again!

Yeah I get that, but according to Firehawk99, my engine was built in mexico even thought the window sticker says US.

Thanks! That's funny because the window sticker says engine country of origin: United States. Ugh.

Just curious - what was your build date? If it were me I'd be sending this one down the road. Wouldn't feel comfortable with only 1/2 of the lifters replaced as they all obviously came from the same batch.

Have you confirmed with RANGE that is how the Pulsar is supposed to function - no engine braking?

My 2016 Sierra with the 5.3/8 speed was like that - part of the reason I got rid of it, crappy 8-speed! My 5.3/10-speed hasn't exhibited that sort of behavior. Pretty smooth so far with 1700 miles on it. How many miles on your truck? I believe there is some "adaptive strategy" that causes the transmission to learn/change shift manners - someone correct me if I'm wrong.