Unfortunately, replacing your vehicle’s transmission is almost always an expensive affair—expect a 2005 GMC Envoy transmission replacement to cost somewhere between $5,450 and $5,900.
Of course, not all of that goes towards parts—roughly $1,650 to $1,800 of the total price accounts for labor costs. Admittedly, however, this will depend on your state and the specific auto repair shop you visit.
The other $3,800 to $4,100 goes towards the parts associated with a 2005 GMC Envoy transmission replacement, though you may be able to find cheaper options depending on what is currently available or if you buy a used transmission.