Revving and Sqealing - clutch or tranny?

[mbzr4ever]

Lately, when starting out in the mornings, shifting from second to third, the engine revs unusually high. Just sometimes, not always, and this is with no pressure on the gas pedal. After the car warms up a bit, problem goes away.

Even more recently, after a long haul down hills (usually in third gear to save the brakes), and after stopping at, say a red light, I shift from first to second, and then to third, I get a loud SQUEAL until I am in fourth gear.

Are these issues related? I just got ripped by a place that charged me to inspect this problem, and their analysis was to get a new transmission for $1400. I kid you not.

This is for my 79 240D, manual tranny.