The other reason to do both is the TC clutch disks get damaged from the slipping caused by the low TC pressure caused by the bad VB. Nice sentence there. What I am saying is that once the control valve in the VB starts to fail, the resulting lower TC apply pressure causes the TC clutch disk to slip and overheat. Once this happens the TC is gone.
I fixed my VB first, and although I had restored the TC apply pressure, the TC still slipped.
jeff
