Need Trans advice with my 82 300SD
 

Friends, I need some advice from the expirenced, I have a 1982 300SD with 195K on the clock. I'm having a tough time getting the transmission to shift properly. The car shifts properly from 1st thru 3rd, but when shifting into 4th, it tends to flare. Only after backing off the throttle, ( if I'm lucky) I get the transmission to finally go into 4th.
I visited the local dealer this week, after briefly discussing the problem with the service advisor, he suggested that the transmission needs rebuilt! I'm reluctant to just replace a transmission that quick!
Please give me some suggestions

Do a search on Trans-X and adjusting the modulator, you will find some steps to try short of a rebuild.