Transmission banging into gears

[Yukongk]

Something new and weird going on with my trans. The 1-2 and 2-3 shift is sometimes banging into gear. It's a firm shift filled by a "knock". Also, sometimes when accelerating from a stop and letting off the gas (like in traffic) before the 1-2 shift, it'll bang/clunk (this was normal on my old jeep, but NEVER had this with my Yukon). I emailed Justin to ask him if he needs to adjust my tune, but everything was fine until a week ago. All I did was a seafoam treatment through the throttle body....can't see how that could be related.
Any ideas?

Thanks

---------- Post added at 10:32 PM ---------- Previous post was at 09:08 PM ----------

Edit: I also washed my engine bay (not sure if there's a sensor I could've damaged).

 

[FrankU]

The banging I'm hearing now with my BB tuned tahoe may be the same you are hearing with yours.

Maybe Justin put to much line pressure in the transmission. Mine sounds like the pinion bearing is getting pounded. Or the pinion bearing is worn and need's to be replaced , adjusted etc.

 

[Yukongk]

The banging I'm hearing now with my BB tuned tahoe may be the same you are hearing with yours.

Maybe Justin put to much line pressure in the transmission. Mine sounds like the pinion bearing is getting pounded. Or the pinion bearing is worn and need's to be replaced , adjusted etc.

This morning I disconnected the battery ground cable for 10 min...started her up and let idle for about 15 min. It's shifting firm without banging, like it did when Justin first tuned it. Not sure what to make of this and not sure if the banging will return. About a week ago I did a seafoam treatment through the TB and washed the engine bay....could I have caused something to go wacky that was fixed with a reset? I also forgot to mention that a sound was present when it was banging into gear. When accelerating I'd hear a sound that accompanied my engine revs...hard to explain but it was never there before...I can't figure out how to describe it.

 

[Yukongk]

Well today it shifted great, but I could hear that banging noise, especially when I braked before a turn and then hit the gas into the turn the 1-2 banged. I took it in for a fluid change. See what happens. I am tired of emailing BlackBear. If anyone has a # to reach them at, can you please PM me.

 

[FrankU]

Changed out the transmission fluid and filter. T-case fluid too.
Banging is gone. Great !!

 

[Yukongk]

I changed mine too and the tranny feels better but the banging is still there during light throttle. I have been back and forth w Justin over the past month and a half and he said he would adjust it, but I am still waiting. It's hard to resolve an issue bc it takes a week between each email response. For now, I just drive with a heavy foot so it doesn't bang.

 

[Yukongk]

I'm probably going to have it flashed back to stock by the dealer. Can't take this clunk anymore and BB doesn't seem interested in sending me the revised tune.