82 300SD, about 15K on rebuilt trans. Problem is primarily failure to upshift 3-4 when cold and sometimes even 2-3. Once it's warm enough, trans shifts fine, as in better than my mom's 79 280E when it was brand new. IMHO, fluid viscosity is exacerbating the problem, as above freezing I never experience it at all. Governor pressure, maybe? I've upped the modulator pressure about 9 psi which helped a little, but just a little. Again, once it's warmed up, it's about as perfect as you could want.

This morning, dropping the kids off at school, we went about 3 miles before it would shift and stay in 3. This evening coming home from work, it took a mile down the interstate at 55 MPH to 3-4 shift, and it downshifted 4-3 on the ramp at about 40 MPH. Today's high here was about 20F, with strong winds, and car has been outside the whole time.

If I do nothing, I know it will go away next month until November, but that's not the point. What do you think is causing this?

__________________
'82 300SD - 361K mi - "Blue"

"Good judgement comes from experience. Experience comes from bad judgement."

listen, look, .........and duck.

Glad to see you again, Pete.

I think you hit the nail on the head with the suggestion of governor pressure. With low governor pressure, delayed shifts would be exactly the symptom.

How about a switch to synthetic fluid? The fellows that use it simply rave about it........bet that solves your issue, at least temporarily. Whether the pressure will continue to drop as you drive it is unknown.