A little more info would be helpful:

1. How many miles on the transmission?
2. What is its service history (e.g., do you change fluid/filter every 30k miles? When was the last service?)
3. How many seconds does it take to engage Reverse? (a fairly good proxy for transmission health -- if it's more than 3-4 sec between moving the shifter and engaging reverse, not a good sign).

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Steve
'93 400E