We are taught in class that cold only issues are almost always related to hard seals. The seal is ridged and will not expand under pressure as it was designed to do. Once it warms it conforms and all is well. This is normal an age thing found on older transmissions. If your trans has been recently overhauled it is unlikely a hard seal. It is possible that it is a valve body/dirt issue but that should not be every single time. It would be more like "most of the time". The hard seal tend to get worse the colder the weather.

This is not a major issue as long as you take it easy while its cold. The pressure lose that is effecting your shift point also means you have a pressure drop at the clutches. Since you trans is not worn out it does not slip but it is weaker cold.

This is the only situation where a "trans medic" product may help. Most of the Trans repair stuff has a seal softener in there. (I have had older mechanic tell me to just put a cap full of brake fluid in the trans, I have never had the ***** to try it on a customers car) There are risks with the "trans medic" Hard seals will soften but the "not" hard seals will soften also and may tear.

 

Well I found my suction gun and sucked out enough trans fluid to put a jug of Lucas trans fix in. Time will tell if that helps any. Thanks for the info guys. I'll let you know if it helps.

 

Just a quick update on the slow shifting when its cold. I decided to install an adjustable vacuum modulator (from NAPA) and set it so it has a quicker shift. It still is a little slower shift when cold but overall it shifts just fine. Case closed.

 

Just go easy on it cold. The slow shift is a result of lower pressure. lower pressure means the clutchs have less holding power. Vacuum modulator may help hide the issue bit the weakness is still there. Once she warms up have at it