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-   -   Cold Weather 6MT Shifting (http://legacygt.com/forums/showthread.php?t=198635)

Byll 12-26-2012 06:48 AM

Cold Weather 6MT Shifting
 
In order to go to college - a whole lot of years ago - I worked a lot of jobs during a lot of summers. One of those jobs was as a truck driver. I was not licensed for 18 wheelers, but any box truck, no matter how big, was mine...

Because I was the youngest guy on the crew, I got the oldest machinery. Most was early 50s vintage. These trucks all contained manual transmissions, with no synchronizers. Learning to double clutch was absolutely necessary. The sound of crashing and gnashing gears was not only unpleasant, but if created within ear shot of the main garage, it was fodder for much derision by the older drivers. The boss certainly did not like it, either.

There have been threads on the MT Legacy's reluctance to shift easily, first thing on a cold morning. I agree, completely. The suggested fixes have mostly been in the area of a fluid change in the transmission - said change ranging from a Subaru product, through 3rd party products, to cocktails. All entail expense and trouble.

Probably out of habit, I have always double clutched my 6MT during down shifts from 3rd gear to 2nd gear, while going around relatively slow corners. Well executed double clutch shifts are very satisfying... I have noted that there is always a finality - a solidity - to the shift, that synchronizers simply do not create.

So, weeks ago, after backing out onto the street from our garage - at around 15 degrees F, I decided to double clutch the shift from 1st gear to 2nd gear - the shift most often mentioned in the threads concerning the cold weather challenges. The procedure produced a perfect shift - no drama, no issues. Hmmm. Transmissions warm up quickly, so I could not try it again that morning.

Many weeks have gone by, with many 1st to 2nd gear upshifts in very cold weather. The result has always been the same: The shift is performed with no cold weather drama.

Simply a heads up... You might wish to try the process with your own 6MT. Nothing is perfect, but this certainly works for me...

Best.
Byll

SurlyOldManMN 12-26-2012 08:01 AM

Taking synchros out of the equation never hurts for rough shifting. :)

One of these days I'll learn how to it without needing so much thought. I have so much muscle memory to combat that I have a really hard time with it. I always want to "re-rev-match" after the second clutch.

Byll 12-26-2012 08:45 AM

I wish I could be there to help, Surly. I had really good teachers. This morning, it is very cold, here. On my way to the body shop, following our daughter in her 16 year old GT wagon to have a tiny bit of rust repaired, I tried the method again - this time slowing it down a lot. Speed of the double clutch process does not matter. While a double clutch can be done in a fraction of a second, taking a second or more has the same effect. And on cold winter mornings, slow is always better. With the slow double clutch, the result this AM was the same - perfect shift from 1st to 2nd gear.

Yep. Rev matching after the second clutch could have unwanted consequences, especially in your LGT.

If I can remember back all those years, I think I divided the process into 3 parts:

1) Release throttle -1st clutch - shifting into neutral - release clutch
2) Rev match/2nd clutch/shifting into desired gear
3) Release clutch/drive...

Kind of like trying to tell someone how to tie a neck tie...

Best to you, Surly.
Byll

Byll 12-26-2012 08:48 AM

I am a music and electronics guy. The best explanation of - and for - double clutching I have ever read, came from an electronics guy. Go figure. For those who might care:

http://electronicdesign.com/article/...ff-anyhow-6137

Cheers.
Byll

SurlyOldManMN 12-26-2012 09:03 AM

Quote:

Originally Posted by Byll (Post 4219122)
If I can remember back all those years, I think I divided the process into 3 parts:

1) Release throttle -1st clutch - shifting into neutral - release clutch
2) Rev match/2nd clutch/shifting into desired gear
3) Release clutch/drive...

Kind of like trying to tell someone how to tie a neck tie...

Best to you, Surly.
Byll

heh, yup. I get the idea and know the steps. I can do it slowly and deliberately. It actually feels like less work when I do it correctly but I go full retard if I don't make it my main focus while driving. I suspect it wouldn't be a problem if it weren't for a couple decades of muscle memory clutching, matching, put in gear and release clutch. Result is an extra rev match thrown in after the second clutch.

There are some good youtube videos that cover the footwork/timing too. Definitely a "tie a tie" topic.

GTEASER 12-26-2012 10:55 AM

Even here in Cali where our winter mornings are typically 30-40 degrees, I have noticed a significant increase in the difficulty of selecting either 1st or 2nd. And have definately ran across the complaints in this forum. Usually the tranny has warmed up sufficiently for this to pretty much stop a mile or two down the road, but I will try this. Thanks for the discussion guys!!

acumenhokie 12-26-2012 01:59 PM

Quote:

Originally Posted by SurlyOldManMN (Post 4219155)
heh, yup. I get the idea and know the steps. I can do it slowly and deliberately. It actually feels like less work when I do it correctly but I go full retard if I don't make it my main focus while driving.

I'm in the same boat. The LGT is the first manual I've owned so I still consider myself very much a novice.

GTEASER 12-26-2012 02:08 PM

I've had manuals before, but all have been synchro'ed and without difficult cold shifting issues, so I have never needed to double clutch. I tend toward the brain farts also. I think its age related....:lol::lol:

Byll 12-26-2012 02:21 PM

To banish the difficult cold morning 1st to 2nd shift, one must only learn to do the most rudimentary double clutch - or 'double de-clutch,' as my friends in the UK call it... And remember that it can be done slowly, and still be effective. The fact that it is continually effective, cold morning after cold morning, makes the learning effort, worthwhile.

The best to you, gentlemen.
Byll

SurlyOldManMN 12-26-2012 02:24 PM

Noted. I'm pretty comfortable with my heel toe technique now after making a conscious effort to do it smoothly until it's as natural as anything else. I suppose it's time to make a special effort to hone something a little more useful in daily driving.

Byll 12-26-2012 03:44 PM

Go for it, Surly. If I can be of any assistance - even to cuss at for putting the idea in your mind - I am at your service. :lol:

Cheers.
Byll

SurlyOldManMN 12-26-2012 04:46 PM

Eh, I don't think anything but repetition is going to help me unless you know any supah slick jedi mind tricks to prevent myself from that extra accelerator blip that I just can't keep from happening even though I'm screaming at myself to knock it off the whole time. :nono:

Byll 12-26-2012 05:43 PM

Repetition works, but only if you repeat the right stuff - just like in music. Practice makes perfect is a crock... All it will do is cement incorrect moves, if one is not careful. Normally, I would say 'isolate the problem - practice it outside of the whole series of movements - replace it in the series, and go for it.' However, we are not talking music, here.

Best I can do is to repeat my suggestion to do the whole double clutch thing slowly. First thing on a very cold morning - with maple syrup for transmission lubricant - speed is your enemy, anyway.

Sorry for no supah slick Jedi mind tricks. All I have is a rather pathetic, old, and jaded sense of common. ;)

Best.
Byll

thebigo 12-27-2012 01:02 PM

Coming from a 2001 Nissan Maxima, whose tranny was a bear in the cold, the GT (2010) is almost pleasant. Will try the double-clutching this afternoon. Issue I'm facing now is an intermittent shriek that sounds like it's coming from the rear diff on very cold days while the car is still ice cold and I'm de-clutching under load, like up a steep hill. I don't think it's clutch related, rather rear diff related. Anyone have a similar issue?

GTEASER 01-03-2013 09:42 AM

Well I have been practicing the 2x Clutch procedure and it works great!!! It's not really that difficult to pull it off fairly smoothly and quickly. I found that if I stopped thinking about how to do it, and just did it, it really is a little more second nature than I would have thought. I started off trying to do it slow and found that frustrating and confusing, and I fully understand what needs to happen, so I gave up on the going slow approach and just did it fast. Once in a while the second engagement of the clutch and rev match isn't perfect but actually being able to get it in gear while cold more than makes up for that. It is already getting better more often. Thanks Byll!!!!!!


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