Shifts better when cool? Please help!

[theAntihero]

Ive got a m5od thats acting sort of strange. I replaced the master cylinder and was resigned to the fact that the slave wasnt far behind but on a whim i checked the fluid in the tranny.

It was super sludgy and old(this car was recently resurrected for a 7 year slumber of sitting in the woods) so i replaced it and added some Lucas. Now when i first start out it shifts fine but the longer i drive it the harder it is to get into 1st and 2nd and the notchier it shifts.

This doesnt make sense to me, how can the slave cylinder "heal" itself when it sits?

Any ideas

 

[cocoasranger]

When I replaced my clutch master cylinder on my truck I found it's almost impossible to get out all the air since the master sits on the firewall at an angle and some air is trapped at the end. This makes shifting touchy, especially after the clutch assembly warms up and expands which explains why it shifts better cold.

You can unbolt the master while it's hooked up to the line, and push in the actuator rod by hand while the master is tipped up which sometimes works. You can bench bleed the master and line as a unit then reinstall which is what I ended up doing. Or have it pressure bled at a shop.

You did not say what you refilled the trans with. I believe the M5OD R1 takes auto trans fluid, not oil. Good luck.