clutch problem when cold

[sultan]

93 240sx

when it's below 80 and the car is cold the trans is really hard to shift and grinds, but after driving a while it becomes buttery smooth. i thought the gear oil may be too thick but i recently noticed (now that it's colder) that the car idles forward (or backward) like an auto when i let off the brake, with the clutch pedal down and the car in gear. when the car's off i can put it in all the gears easily, clutch pedal goes up and down like normal.

air in the line? bad slave cylinder? needs adjustment? when it was hot outside there was no problem as far as i could tell.

[sultan]

anyone? i'm probably going to replace the line with an spl braided stainless one and probably replace the clutch slave unless someone has some ideas.

also, the damper box has already been ditched

[ralphdig]

You may need to change the trany oil (75w90) and have your clutch pedal adjusted.