Car refuses to shift - help

[Kerrath]

I went to drive my car two days ago and I couldn't get it to shift. I eventually got it into reverse by turning off the car. After that, I was able to drive it to where I needed to go. This was at 7:15ish am. After about 5 blocks, the transmission was whining very loudly in 1st gear, but not second. When I drove it again around 1 pm, it drove just fine like usual and was fine the other two times I drove it.

Yesterday, I tried driving it again in the morning and once again, I could only get it into 1st or reverse by turning the car off. It was worse than the previous day so I had to park it on the street and ride my bike. When I came home, I moved it into the driveway and once again it shifted fine.

Because it only has problems in the morning, it seems that the problem is temperature-related. In addition, only 1st and reverse seem to be affected.

It seems to me like my clutch might not be fully releasing, or it could be something else, as I don't have a strong knowledge of the innards of the transmission. Does anyone have an idea of what could be wrong?

It has been suggested that the gear oil is low and also another person suggested that the rubber in the pistons of the master/slave cylinder(s) could be shrinking small enough to not seal. I need my car again. Please help.

[whiltebeitel]

+1 on the fluid level. check it first (cheapest to fix) Make sure the fluid is up to the top of the fill plug on a level surface, and if that's still bad, bleed the clutch, then see if the clutch is fully disengaging.

Your 1st gear synchros could be going bad, but it may just be a shifter linkage problem. It may not be able to select the gear properly.

[Kerrath]

+1 on the fluid level. check it first (cheapest to fix) Make sure the fluid is up to the top of the fill plug on a level surface, and if that's still bad, bleed the clutch, then see if the clutch is fully disengaging.

Your 1st gear synchros could be going bad, but it may just be a shifter linkage problem. It may not be able to select the gear properly.

Thanks for the response. If it were a linkage problem, I would think it wouldn't suddenly start shifting later in the day, but I'll check while I'm down there. Why could low fluid prevent 1st and reverse, but not any other gear?

A bit more info I forgot to mention:
M50 Swapped car with m50 flywheel pressure plate and clutch and using the original getrag 260 slave.

[Kerrath]

Mitchell and I were gonna take my car over to duarte to check the fluid level in the tranny, but when I pulled it out my driveway in the afternoon, it started giving me trouble. So far it hadn't been a problem when it was warm. Anyway, the release point of the clutch suddenly raised to the very top of the pedal's travel, then the pedal didn't return all the way up. I pulled it up with my foot, drove it back in, and then it started acting normal.

My brake fluid level is not declining, so is it my master cylinder that's dying?