All,

I've got a 1989 Ford Country Squire station wagon that runs great with one exception. On hills, the transmission seems to "miss" when in overdrive -- like a sparkplug misfiring, but it doesn't happen in "drive" so I'm assuming it's not a sparkplug problem --could I be wrong? Runs fine on flat roads or mild inclines.

Are there any owner-serviceable parts for the overdrive, vacuum hoses to check, etc.?

And one final note -- I've never changed the transmission fluid/replaced the filter.... but it doesn't smell burnt or appear dirty.

Thanks for your help!

Bruce
North Carolina"