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Re: Can't find it grind it

To: <datsun-roadsters@autox.team.net>
Subject: Re: Can't find it grind it
From: "Craig Odell" <CDADDYO@prodigy.net>
Date: Sat, 17 Feb 2001 22:52:51 -0800
Gordon,

Once again, a thorough explanation!
Man, it is nice to have you on the list.
I'm going to practice right now.

Thanks,
Craig

-----Original Message-----
From: Gordon Glasgow <glasgow@serv.net>
To: Craig Odell <CDADDYO@prodigy.net>
Date: Saturday, February 17, 2001 9:29 PM
Subject: RE: Can't find it grind it


It's a bit more complex than that. Basically what happens is this (on a
downshift):

1. Put the clutch in and shift into neutral.
2. Let the clutch out and blip the throttle.
3. Put the clutch in before the revs drop.
4. Shift to the lower gear and let the clutch out.

What this does is, it uses the engine to accelerate the tranny components up
to a higher speed (when you blip the throttle). Then the synchro has less
work to do to match the speeds of the components.

It feels really awkward at first but once you get it, you can throw a
downshift from 5th all the way to 2nd coming into a very tight turn and make
it completely smooth with no graunching. It's really great.

It used to be a "basic" move that all racers knew, but then they started
building custom race gearboxes where you don't even have to use the clutch
except to start. Takes all the fun out of it.

Gordon Glasgow
Renton, WA

-----Original Message-----
From: Craig Odell [mailto:CDADDYO@prodigy.net]
Sent: Saturday, February 17, 2001 8:29 PM
To: Gordon Glasgow
Subject: Re: Can't find it grind it


Gordon,

I've never heard of "double clutching".
"Double clutching" just means depressing the clutch twice before shifting?

Craig
68 2000

-----Original Message-----
From: Gordon Glasgow <glasgow@serv.net>
To: Craig Odell <CDADDYO@prodigy.net>; datsun-roadsters@autox.team.net
<datsun-roadsters@autox.team.net>
Date: Saturday, February 17, 2001 6:48 PM
Subject: RE: Can't find it grind it


2nd gear synchro is always the first to go out, because it gets the most use
in traffic. And shifting down into a gear is harder on the synchro than
shifting up because it has to accelerate the countershaft, input shaft and
clutch disk up to the speed that they will be going in the lower gear.

Switching to something like Redline MTL can make it better provided you
don't wind up with leaks. A better solution (short of rebuilding the tranny
and replacing 2nd gear synchro) is to learn to double-clutch on the
downshifts. Takes a bit of practice to get it, but it eventually becomes
second nature. I automatically double-clutch all my downshifts to either 2nd
or 1st no matter what I'm driving - except the Maxima automatic. ;-)

Gordon Glasgow
Renton, WA

-----Original Message-----
From: owner-datsun-roadsters@autox.team.net
[mailto:owner-datsun-roadsters@autox.team.net]On Behalf Of Craig Odell
Sent: Friday, February 16, 2001 5:15 PM
To: datsun-roadsters@autox.team.net
Subject: Can't find it grind it


Hey Roadster folks -
I've been having difficulty down shifting from 3rd gear into 2nd gear.
It will grind every time unless I am going extremely slow (slow enough to
actually be in first).
I replaced the 5th gear last summer with "The Tillinger 5th Gear" (Monster
truck voice here too).
But I don't recall if I had the problem before the gear swap as it was a new
car to me.
Could this be a problem with gear oil?
Or do I need to consider a total rebuild?
The tranny seemed very clean at the time of gear swap.
TIA

Craig Odell
68 2000

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