I've been searching for answers for a while now and it looks like this is a very common problem for all manual 147 gears. There is a lot of recommendations for a solution but it looks like it is the gear selctor plate (linkage unit) which Alfa has redesigned is the part which should be replaced. I seemes like there was a user who had some pictures on how do it in this POST
, but there gone. I'm very interested in getting those picture if someone has them.
Here is a summary in which order I will try to solve my problem:
1. Check oil level and replace oil in transmission if necessery.
2. Grease gear cables and replace them if they look worn out.
3. Replace gear selector plate
4. Replace bushing in gear stick housing and end of linkages
5. Replace whole gear stick housing
6. Look for eventual swarf from inside of gearbox.
I'm a newbie and wonder if my conclusion seems relevant, error searching is in right or if I have missed something to look for.
Points 1 to 4 doesn't seem to cost so much but the cost increase with point 5 and also 6 if you don't do it yourself.
It also seems that it is not recommended to continue using the car for a long while without fixing the problem. Some people have got used to shifting the gear anyway but caused further problems with higher costs.