There had been a problem in my transmission for a long time. I could not force it to first gear with the shifter. I tried adjusting the shifter cable many times but it just did not work. The shifter lever in the transmission felt somehow loose when turning it by hand and just didn't go to first gear. I searched the net for possible causes and found that a loose nut at the inner end of the shifter shaft could be the problem. Oh well, at least that's pretty simple to check and I needed to change the oil and filter anyway.
Unfortunately I had to work in my really small garage again. To get some room under the car, I bought a pair of ramps. With them, I had just enough space to remove the oil pan. So I drove the Corvette on the ramps, added some wedges behind the wheels and got to work.
I drained the old oil to a container and removed the oil pan. It was exiting to see what it would look inside the transmission. The last time that I opened it up with my friend, it had probably been standing for a while. We were a bit worried how much crap had been stuck in the fluid passages and if it had loosened up after the car had been driven for a few hundred kilometers. The oil didn't seem too bad but there was some crud in the pan. The magnet was clean so at least it was just dirt and not metal.
I cleaned the pan and removed the old gasget. Next it was time to crawl under the car again and check the filter. I removed it and couldn't see any dirt. Hopefully most of the crap was now out of the transmission.
Finally I got to the part that I wanted to see: the nut at the end of the shifter shaft.
I tested the nut with a wrench and it did feel a bit loose. There was not much room but I could turn the wrench enough to tighten it. I tested the shifter lever and the play was gone! Perhaps the transmission was now fixed!
It was time to put the transmission back together. I screwed in the new filter, used some silicone to keep the new pan gasget in place and finally bolted the pan to the car. Lastly I filled the transmission with new oil and took the car for a test drive.
And what a difference this small fix made! The shifter was no longer loose and the transmission was much quieter. Previously there had been a jerk and clank when changing gears between reverse and drive. Now the shifts were smooth and quiet. It was hard to even notice when the transmission went in gear.
I still could not get the first gear activated as I had forgot to adjust the cable. While doing that, I noticed a small mistake. When tightening the shaft nut, it had turned the lever a bit. This meant that the cable had to be adjusted to its maximum limit and even that was barely enough. I still could not always get the shifter to first gear. It worked about half of the time.
Oh well, I'll have to tighten the nut again during the next oil change. At least the transmission works much smoother now.
