DFM Disabler that works for 2021 Silverado, 6.2/10 speed

[AirForceAngler]

Ok, so I have a 2021 Silverado with the L87 6.2 and 10 Speed with about 48K miles on it right now.  At 9K it had the right bank of lifters and pushrods replaced, then a few months ago, an actuator for one of the valves on cylinder #8, can't remember which one.  Hoping to avoid more of this, I ordered the Range Technology disabler RA003B.  After running this a bit, I noticed that it surges when cruising.  I have emailed Range about it and will call them tomorrow, but was wondering if there is a device that actually works well?  I do have a very good extended warranty that I don't want to void as well.  Thanks in advance for any advice!

[newdude]

A lot of folks run the Range Pulsar LT on the 2019-2022 trucks.  Range Technology 22451 Pulsar LT for 2019-2022 GM Gas Trucks

 

The surging you have.  When does it occur?  So like at certain speed, RPM, etc.

[johnnyquick]

On 12/21/2025 at 6:15 AM, AirForceAngler said:

Ok, so I have a 2021 Silverado with the L87 6.2 and 10 Speed with about 48K miles on it right now.  At 9K it had the right bank of lifters and pushrods replaced, then a few months ago, an actuator for one of the valves on cylinder #8, can't remember which one.  Hoping to avoid more of this, I ordered the Range Technology disabler RA003B.  After running this a bit, I noticed that it surges when cruising.  I have emailed Range about it and will call them tomorrow, but was wondering if there is a device that actually works well?  I do have a very good extended warranty that I don't want to void as well.  Thanks in advance for any advice!

I have been running the Pulsar LT for 50,000 miles now no issues at all LOVE it!

Does all sorts of stuff check it out the above poster is linked I believe 

[Bikerjon]

On 12/21/2025 at 8:15 AM, AirForceAngler said:

Ok, so I have a 2021 Silverado with the L87 6.2 and 10 Speed with about 48K miles on it right now.  At 9K it had the right bank of lifters and pushrods replaced, then a few months ago, an actuator for one of the valves on cylinder #8, can't remember which one.  Hoping to avoid more of this, I ordered the Range Technology disabler RA003B.  After running this a bit, I noticed that it surges when cruising.  I have emailed Range about it and will call them tomorrow, but was wondering if there is a device that actually works well?  I do have a very good extended warranty that I don't want to void as well.  Thanks in advance for any advice!

I have used a Range Technologies DFM disabler on my 2021 and 2023 Trail Bosses. Now I am running a new style Range device on my 2025 Trail Boss w/6.2. I've never had surging or any other performance issues with my Range devices, are you sure the Range device is causing your surging at cruise speeds? Maybe unplug it and road test to verify?

[AirForceAngler]

On 12/22/2025 at 10:05 AM, newdude said:

A lot of folks run the Range Pulsar LT on the 2019-2022 trucks.  Range Technology 22451 Pulsar LT for 2019-2022 GM Gas Trucks

 

The surging you have.  When does it occur?  So like at certain speed, RPM, etc.

Most commonly around 62-64 MPH or so.  It has done it as high as 75 MPH.  It seems to do it when I would assume the DFM would kick in, like straight or slightly downhill areas.  I heard back from Range and they admitted it was a problem on certain, early 6.2s with the 10 speed.  It has something to do with the early TCM programming.  Feels to me like it's the torque converter locking and unlocking.  Going to return it for refund, hopefully.

[AirForceAngler]

On 12/22/2025 at 9:15 PM, Bikerjon said:

I have used a Range Technologies DFM disabler on my 2021 and 2023 Trail Bosses. Now I am running a new style Range device on my 2025 Trail Boss w/6.2. I've never had surging or any other performance issues with my Range devices, are you sure the Range device is causing your surging at cruise speeds? Maybe unplug it and road test to verify?

Yes, I'm sure it is the unit.  It is now removed and ready to be returned.