put a low mileage rebuilt dual range hydro behind a 317 y block about a year ago. Works great except it wont shift past 2nd for the first half mile or so. After that the shift points are great. Running Dex/Merc III, I think when I checked its at about the halfway point on the dipstick. I've tried both D3 and D4, same results. Maybe top if off? Maybe the fluid hasnt expanded enough when its cold?
My 400 turbo in my hot rod will act real funny if it is only a half quart low so my vote is to make sure it is right on the full mark. Can't go wrong there.
Had the same problem with my pontiac powered 55 chevy when My dad And I built it when I was 16. We put more fluid in it after screwing with it for 2 days and it worked fine.
Could be a "sticky" 2-3 valve in valve body. When it warms up it works like it should. I had my 54 Olds valve body cleaned and when the bumpkin at the trans shop reassembled it he forgot to tighten the three screws holding a small plate which leaked enough to have a very sloppy 2-3 shift, so I would think your problem may be valve body related. BTW: Lincoln 317.5's are good engines and the hydro works real good behind them, I know having a 54 Lincoln Capri.
Top it off for sure, my 54 hydramatic was shifting a tad crappy, after adding half a quart of Dex III to bring her just to the fill line she shifts like a champ, could also be something sticky as d2_willys noted.
i went to advance auto parts, they no longer carry a bottle with Dex III on the front. Now it says Domestic Vehicle ATF and in little letters it says meets Dex III requirements. Is this the stuff to use now?
Yes that is the stuff that is replacing dex 3. try a bottle of red lube gard. It will help to keep the valves free.
I am not sure if that tranny has a vacume modulator but I had a vacume line from the intake to the modulator leak air at first when cold and not allow my tranny to shift till it warmed up. A new vacume line fixed mine.