Hello Scotty,
I have a 2012 Toyota Corolla with 211000 kms, 1.8l engine and a 5 speed manual transmission. For the last few months I have been hearing a grinding sound when I shift the transmission from 2nd to 3rd gear. The grinding stops once I am in 3rd gear and this only happens when it is relatively cold (below 10 degrees C or below 40 degrees F). The issue stops when the car warms up. I am thinking that it is an issue with the syncro gear. Should I change my transmission oil? I do not think the oil has ever been changed and I'm thinking of using Redline.
Should I change my transmission oil? I
Your answer is in the FAQ.
I have been hearing a grinding sound when I shift the transmission
Watch Scotty's video on Youtube related to this issue. Do on Youtube Finding the sources of car noises. Scotty. It's on Youtube. It's also linked here.
It does sound like your 3rd-gear synchro may be wearing out. You can see if fresh lube will help the problem. You can also double-clutch when shifting from 2nd to 3rd gear to reduce stress on that synchronizer.
