I drive a Mk5 Golf GT TDI 140 with a 6 speed gearbox. I am using the correctly specified gearbox oil only recently changed which is G 052 171 A2. I am suffering from a grinding gear change from 1st to 2nd gear ONLY WHEN COLD after 20 mins driving the gearchange is absolutely fine, in fact the gearbox feels completely different when warmed up, it's heart breaking to start up the following day only for it to grind 1st to 2nd again. I have done a TON of research on this and it seems that many with notchy/grinding shifts have reported great success using alternate gearbox oils like GM or Pennzoil Synchromesh. As my issue is only an issue from cold I'd like to try a different gear oil before I spend big bucks to have a new syncro installed, so please can you let me know if you have any suggestions? Thicker or thinner oil? Has anyone tried any of the synchromesh oils in their 6 speed gearbox with success? (GM/AC Delto, Pennzoil Syncromesh etc) The specified VW oil is G 052 171 A2 which is fully synthetic 70W-75 (6.5 cSt) Many people reporting much better shifts using Pennzoil Synchromesh which I believe is a mineral oil 75W-80 (9.3 cSt) Is there any reason why Pennzoil Synchromesh spec would help a gearbox with tired synchros shift better in the cold? Many regards.