'85 300D Slow tranny engagement

[dsmess]

When shifting from neutral to drive (or reverse), engagement takes about 3 or 4 seconds...there is also no sound at all it is so soft. If I push the throttle down early, there will be a clunk to remind me I did not wait. the car drives ok, but the shifts feel softer than I'd like....after doing a search, it sounds like the symptoms match those with a broken tranny pressure regulator valve spring which Sonnax is selling....anybody have a similar problem? I also have an '84 300TD which works fine, and is where I'm getting my comparison.

Thanks