Hi Arthur,

The one thing to remember though is that the upshift delay system can only retard shifting the amount a full throttle shift would. Even if the cable gets stuck fully pulled.

I'd also suggest the kickdown switch, but it also won't prevent a shift, only delay it. I started to write about the common no shift problem of the check valve spring jamming the secondary pump and then breaking the governor drive gear. But that car probably doesn't have a secondary pump. It would have a governor though and I have seen them stick. I would surely check governor pressure as a first step.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician