Transmission fluid exchange on '85 300SD

[hipcat58]

Hello, gang. I just inherited a 1985 300SD. Been sitting in a garage for nearly four years. It has nearly 112,000 on the dash, but runs great. The transmission shifts a little rough, but that's to be expected because of the car's age and inactivity. My question: Should I change out the transmission fluid and filter? I've talked to three shops today and, of course, a couple of them are ready to flush it out ... but don't do the filter service. One guy said if it wasn't done before 100,000 miles, don't flush or change the filter because it could hurt the transmission. Sediment, I suppose. Like I said, the others are ready to flush through the dipstick but don't do the filter service. Guess very few shops drop the pan these days. What should I do? Ideas would be appreciated. Thanks. Hipcat58

[rocky raccoon]

drop the pan and change the filter. A flush will not hurt either. Don't forget the torque convertor (separate drain plug).

Your shifting issues are probably due to vacuum problems. Check your shift modulator and inspect your vacuum hoses and connectors for old age rot.