1.2TSI 6-spd 2nd Gear Synchro

[trive2]

Hi All,


So the story begins with a 120,000km major service, change of brake fluid. Of course we failed to notice the clutch takes from the top of the reservoir, and we let air in.

Tried all sorts of bleeding techniques- every mechanic and his dog (Including Volkswagen themselves) advised us on how to do it properly and nothing worked.
Took it to a mechanic who didn't do it properly.

Finally found a bloke who power bled it, reckoned there was **** loads of air sitting in the master cylinder.

Since then the box has been mostly amazing. Beautifully weighty changes through every gear (except second) and the horribly lurching changes I was experiencing with the air-con on are gone!!!

However, second gear is still gravelly and a tiny bit crunchy on maybe 30% of changes up and down? It also makes me try for first a couple of times around 50% of the time.

I'm aware that Volkswagen has a habit of making **** synchro rings and these 6-speed boxes are particularly glassy. I'm concerned that in the time the month or so it took me to fix the problem while the clutch wasn't disengaging properly, I've damaged the box.

Is anyone aware of similar issues with the little 6-Speed? There are some assorted topics where a change of gear oil was the solution- does anyone know the ideal gear oil for the job?


TL;DR
Second gear is crunchy. How do I fix it.

[alexaescht]

Second gear is crunchy. How do I fix it.

I would take it to a mechanic who knows what they're doing, and ask them to diagnose the problem. If second doesn't shift smoothly and crunches, it is highly likely that the synchro is worn to where it's getting ineffective.

[grandturismo]

Sounds like you have syncro issues which means you'll have to get it looked at. Good gearbox oil can help depending on how bad it is, so perhaps try that first. I'd recommend Redline but depending on the workshop they may offer another option.

Generally speaking, if your syncros start crunching your syncro rings are loose and the gear isn't engaging correctly. This will require it to be opened up and fixed = big job and big $.

I just had my gearbox opened up recently from a crunching 4th gear in my GTI and it was a long and expensive exercise.

Red Line Synthetic Oil - Gear Oil for Manual Transmissions

[LukePolo]

I had an extremely unlikely case, at 55,000km my 2nd gear syncro had failed completely coming off the motorway and needed to be repaired, VW couldn't repair it due to lack of tools, so I got a brand new gear box.