Im new to this forum. I drive an 18 GMC Sierra, bought new. Currently has 113k miles on it, mainly HWY. I will occasionally pull a 4 wheeler, nothing serious. It is in the shop currently getting the transmission rebuilt. It has the 6 speed.
Had no issues up to a week ago, then it started lagging with acceleration. Then hard shifts to complete failure. The local transmission shop I took it to said they rebuild 4-5 a week. Probably bigger issues here that should have triggered a recall.