Need some help

[Mooseorcaboose]

Hey folks! First post here so please bare with me if missing info or wrong area to post in.
I have a 07 5.9 24v with roughly 230k on her. I purchased the Truck used at about 190k. Everything has been fairly smooth other than usual maintenance and suspension wearing out. I have the truck running a Smarty S04 tuner and keep it on a mild setting and rarely give her the beans so to speak. If so ramp into the power no boost launches or wild erratic driving. With all that being said the last couple weeks I have noticed one singular knock coming from what sounds my transmission (48re) when warmed up and going into throttle. Right as I tough the pedal it thumps. Mostly from 3rd gear on up. In the last couple days it happens when letting off the throttle but much more subtle. It hasn’t been all that long, well within time from fluid changes. I’ve checked fluid level and everything was fine and no burnt smell. and everything seems to be just fine. Every so often it seems like the truck wants to hang before changing gear but no slipping or harsh, slamming gear changes. I’ve checked unjoints as well and all seems to be fine there as well. I’m at a loss and have been on multiple forums trying to figure out what this is. If anyone has suggestions or have had this issue in the past please chime in and help me figure this out.
Thanks -Mooseorcaboose

 

[Darkbloodmon]

Take the tuner off or set it back to stock. This is a mute point but tunes on a truck you don't have full inventory of is a recipe for disaster, even more so with higher mileage on a stock trans.

I don't know much about the autos besides not wanting one but I'll be following for details. For reference if you can get ahold of a factory service manual for your model year look in the transmission section for the 48RE there will be a diagnosis chart with a list of symptoms/issues and related potential causes and fixes. If you can isolate your symptoms to an item(s) on the chart it could give some more detail and direction to the problem you have and help anyone suggesting a repair based off what you're experiencing.

Welcome to the Forums.

 

[Ozymandias]

Tuner and stock Trans? That's a sure recipe for disaster.

 

[cerberusiam]

Check your flex plate to TC bolts and make sure they are not loose.

 

[Mooseorcaboose]

Check your flex plate to TC bolts and make sure they are not loose.

awesome I will certainly check that out. Thank you for giving me some type of direction here.