Scraping noise when shifting cold from 1st to 2nd gear
Discussion
My 2006 Vantage had the later mod/oil and didn't have any issues after that. My 2012 4.7 has later oil etc and continues to be crunchy from cold. However, it really is just the first few gear changes of a drive from cold. After 5-10 mins of driving once its warmed up its fine. I can cope with double de-clutching for a few gear changes until engine is warm.
What is the technical explanation ? is it something like the clutch plates sticking in cold oil ?
What is the technical explanation ? is it something like the clutch plates sticking in cold oil ?
It's simply thickish oil dragging round the non-engaged gears. Once the oil warms up it is sufficiently thin to allow the gears (or synchro cones) to be at the design relative speed. It's obviously a marginal thing since Aston use a slightly thinner oil as a 'fix'. Nothing to do with the clutch, which is dry, and nothing to worry about from a service or life viewpoint. I change from 1st to 3rd for the first few miles.
First short drive today after almost seven months and indeed: No scraping or crunching at all on first (slow) shift into 2nd gear (as a precaution I had shifted through all gears before rolling off). The problem seems to have vanished. Still not the best gearbox/transmission in the world I would say, but probably as nice and smooth now as the six speed manual gets. Happy owner 
Astounding how well the car seems to take the long standing time. Nothing to report but instant and smooth re-awakening and drive. Beautiful.
Astounding how well the car seems to take the long standing time. Nothing to report but instant and smooth re-awakening and drive. Beautiful.
Thread revival out of interest because of the latest Bamford Rose video exhibiting the exact problem that I had described:
https://www.youtube.com/watch?v=urUgNXOUeVw
Interestingly the car in the video is also a MY16 onwards Manual with no trouble at all getting into second gear when cold - but sadly with a scraping noise.
After ca. 1,000 km the problem had vanished on mine (if shifting slowly) and my personal advice for this owner would be to try to shift forwards and backwards through all the gears before rolling off cold. Worked wonders on mine (although I don´t really need to do it anymore). Good luck to him and thanks for making this public!
https://www.youtube.com/watch?v=urUgNXOUeVw
Interestingly the car in the video is also a MY16 onwards Manual with no trouble at all getting into second gear when cold - but sadly with a scraping noise.
After ca. 1,000 km the problem had vanished on mine (if shifting slowly) and my personal advice for this owner would be to try to shift forwards and backwards through all the gears before rolling off cold. Worked wonders on mine (although I don´t really need to do it anymore). Good luck to him and thanks for making this public!
bogie said:
Great video by Mike at BR as usual and really explains the issue well.
My 2012 4.7 is not that bad, on cold mornings its just a bit crunchy, so shift 1st to 3rd for the first couple of gear changes and its ok after that.
Watching that video made me wince. Having the gearbox baulk when it's cold is not the same as the 'box letting the gear engage without the synchro fully doing its work, so that there's a crunch caused by metal bits moving at different speeds being brought forcibly together. My first thoughts would be clutch drag due to not fully disengaging or worn synchro on 2nd.My 2012 4.7 is not that bad, on cold mornings its just a bit crunchy, so shift 1st to 3rd for the first couple of gear changes and its ok after that.
Sure seems like worn synchros. You might be able to mitigate it with fluid or skipping gears while cold, but the real solution is to replace the synchros and diligently apply mechanical sympathy going forward. I'd ask how many miles are on it, but I've driven with people who can destroy synchros in a single day driving around the city...
Luckily(?) your clutch will go pretty soon, so you can pull the gearbox and do it then...From then on, shift with a smooth one-two rhythm to give the synchros half a second to do their job, instead of jamming it from 1st to 2nd in one yank as seen in the Bamford Rose video...I've never seen anyone move a gear lever like that.
Shifting from 1st to 3rd is a fair mitigation technique, but if that's what's expected of people from a factory-fresh Aston...it's a bit shameful. Can't say whether it is or isn't, because my car has done the same thing since I bought it with 40k miles!
Luckily(?) your clutch will go pretty soon, so you can pull the gearbox and do it then...From then on, shift with a smooth one-two rhythm to give the synchros half a second to do their job, instead of jamming it from 1st to 2nd in one yank as seen in the Bamford Rose video...I've never seen anyone move a gear lever like that.
Shifting from 1st to 3rd is a fair mitigation technique, but if that's what's expected of people from a factory-fresh Aston...it's a bit shameful. Can't say whether it is or isn't, because my car has done the same thing since I bought it with 40k miles!
philipm785 said:
Curious for the future: can synchros for these boxes be ordered separately and replaced?
As far as I know, yes. Requires a complete strip-down of the gearbox and removal of all the shafts, then stripping the mainshaft cluster down to its individual component parts and renewing the synchro cones, along with any worn bearings, chipped teeth, etc. Then reassembly, shimming all the required clearances to tolerance, renewing seals and gaskets. Not a job for the faint-hearted and under-skilledAdditional and summarizing comment from Mike Beake on how common or uncommon the 2nd gear crunch is from 14.01 min. onwards:
https://www.youtube.com/watch?v=nfm-AOqC8zg
https://www.youtube.com/watch?v=nfm-AOqC8zg
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