Look at the flame diffuser - the box that sets over the burn pot.. GMG redesigned the diffuser at some time in the past and widened the ‘locating notches’ on the bottom of the diffuser box. If your notches are wider than the tabs they set in - slide the diffuser box to the left - which should divert more flame and heat to the right of the box.. Then check your temps from left to right and they should balance out a little more if your unit is ‘adjustable’.
I'm really good at checking my left to right temps, it's the back left that is hot. Yes I do have the newer style heat shield. Just can't figure out why the left rear corner tends to run about 15 degrees hotter than anywhere else.
That’s a good question as to why.. You could expend a lot of time and thought into re-engineering to correct the issue or you my keep this in mind and rotate/shift your cooking load from left to right - front to back about halfway through your smoking/cooking time.
In all reality, IMHO - 15d is not ideal - but it it is real close and workable.. All of these pellet units will exhibit their little ‘idiosyncrasies’ here and there. Knowing your units ‘character’ can sometimes be used to your advantage - either working with it or around it..
Try starting it up with the lid open and drip trays out - just the flame diffuser in place and observe the flame and heat distribution from the burn pot, then shutting it down and when cooled down, look and study the underside of the diffuser. A solution may come to mind on how to adjust or modify the diffuser to limit the flame/heat to the LR corner..
Best regards, and keep your GMG busy this upcoming weekend..
Tis the season,….