Huh? None of my cars do this (my truck does tho - big time).... 20d is cold here, maybe not for youse guys. Bruce

 

All my cars do this when it's sub 20. My 951 used to, my M5 currently does. If I don't let the gearbox warm up I need to double clutch or skip certain gears when it's stone cold.

 

Only if something is broken (like a leaky master/slave cylinder or having air in the lines), and even then it would not be temperature dependent. Even if something were broken and pumping the clutch did help, it would affect every gear, not just 2nd.

Hydraulic fluid is incompressible. No matter what the temperature is, if you put the clutch pedal all the way down, the clutch is fully disengaged (assuming no air in the lines and no leaks).

 

Understood, but not exactly true. Compressibility is a measure of the amount of volume reduction due to pressure. Petroleum production fluids (like ours) are relatively incompressible, but volume reductions can be noticeable (5%-12%) for pressures ranging from 500lbs per sq. inch up to 3200lbs per sq. inch in. Compressibilty increases with pressure and temperature and his significant effects on high-pressure fluid systems. Like most petroleum products (and every other liquid on this planet), hydraulic fluids are subject to the laws of Molecular Translational Energy and their applicable equations and applications as well as volumetric expansion calculations. Line limits and fill level requirements are thus subsequently paramount in regards to the isolation of potential failure of servos, drives, piston assemblies and perhaps more importantly cavitation (which typically results in material fracturing and/or corrosive fatigue...either way failure).

Just sayin'....

 

And if the temperature hits -273 Kelvin, the fluid will definitely have frozen, or if we throw the car into the center of the sun, the fluid will boil off.

There are situations where such extreme considerations as you mention are relevant. This isn't one of them. I saw, and still see, no purpose to bringing up conditions that are simply not applicable.

 

When my trans is cold the first to second is stiff and I'll crunch second if I forget to double clutch. After the trans warms up it is smooth as silk.

 

I believe that ambient conditions in the ranges of 30 F to 5 F are applicable. I was not referring to the rate of rise, nor the rate of molecular suspension. It is the flow rate of the fluid that I was referring to. The less efficient hydraulic fluid may pass = the less the efficient actuation of the application device or apparatus.The flow rate of some hydraulic fluids can be significantly reduced in temperatures as common as =/< 28.6degree F.

The statement of hydraulic fluid freezing at -273 Kelvin (-951.1 F) is a bit over the top. The majority of hydraulic fluids have a solid state potential of, IIRC -50 to -70, depending on the exact type and application. However, hygroscopic fluids (like the one in our cars) further detracts from this (to a degree) due to its intentional ability to absorb moisture. Obviously additives and the such can lower the freezing point further but you get the idea.

So... the flow rate at low temperatures is not as efficient, thus resulting in the potential for reduced actuation at low temperatures until desired pressure and/or operating temperatures are achieved. Subsequently resulting in increased pressure or repitition of valve actuation for desired or intended reactive performance parameters.

All I was saying is that when mine is cold, and does not want to easily go into first gear, I simply pump the clutch 2-3 times and it slides right in....that is all. I guess mine is unique. IIRC, this is actually covered on page 31 of your owners manual (...will require the clutch to be fully depressed on cold shifts...or something along those lines).

 

My 1 to 2 used to be kinda crunchy. It mostly noticeable in the cold but after I changed the trans axle fluid it got alot better. I didn't think it would but it did. I think I used redline MT-90. I know it was redline but I think it was mt-90. Whatever Lindsey Racing was peddling before they started selling Petroleum fluids. Go get a bottle at your local speed shop, and take to a jiffy lube or somthing.

BUT watch them and tell them not to touch anything else. Trans fluid on these cars is harder than any fluid change should EVER be.

Considering the fluid should be changed anyways its a great start to trouble shooting any problems you might have.

 

I bought my car with 120k miles, immediately had the tranny drained and redline fluid installed. I too thought it had a slight improvement. My 2nd synchro really needs to be replaced but I wonder if this is the cure. I have no problem in the cold shifting to any other gear including reverse, 1st is stiff when the car is rolling.
I find it amazing that when its cold and raining it shifts much easier, the clutch pedal engaging the clutch is also easier AND NO ONE CAN OFFER A REALISTIC EXPLANATION FOR THIS ANBNORMALITY. Thanks for the replies.