Transmission oil and downshifting into first

Loppysaurusrex

Loppysaurusrex

Well-Known Member
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So 2 questions here: How often do I need to change transmission oil? I got about 33k miles on my 2013 SI and second and 3rd are getting a little notchy.

And

Can you safely downshift INTO VTEC in first gear? Or is first gear mechanically less rigid than the other gears?

I know when you put my car into first in anticipation of a downshift I can hear something start to spin, not sure what that is and what it means.
 
Don't over rev downshifting too early. I think that's all you would have to worry about with 1st but that is a pretty short gear. Other than getting going I don't think you would ever really need to downshift into 1st as long as you're moving a little bit.
 
1st has a lockout and won't let you downshift into it until your rpms are low enough. If you attempt to put it in 1st (if you're at say 6k or something) it'll just block the shifter from going into gear.
 
Loppysaurusrex said:
So 2 questions here: How often do I need to change transmission oil? I got about 33k miles on my 2013 SI and second and 3rd are getting a little notchy.

And

Can you safely downshift INTO VTEC in first gear? Or is first gear mechanically less rigid than the other gears?

I know when you put my car into first in anticipation of a downshift I can hear something start to spin, not sure what that is and what it means.
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An earlier post says there's a 1st gear lockout to prevent going into first at too high a speed. The real risk is catching any lower gear at too high a speed such that when you drop the clutch, if used, you mechanically over-rev the motor well beyond, say, 8000 rpm. This is most likely to occur attempting to upshift under full throttle but instead catching a lower gear by accident - the ECU fuel cut-off doesn't protect the engine as it's the driveline pulling the engine beyond its limits. I've almost done this in our Si once or twice at less than full song and fortunately didn't do anything but scare the hell out of myself. I've had the experience of taking a chip out of my buddy's Rover TC camshaft doing this in my younger days. It ain't pretty and it ain't cheap!
 
tacthecat said:
An earlier post says there's a 1st gear lockout to prevent going into first at too high a speed. The real risk is catching any lower gear at too high a speed such that when you drop the clutch, if used, you mechanically over-rev the motor well beyond, say, 8000 rpm. This is most likely to occur attempting to upshift under full throttle but instead catching a lower gear by accident - the ECU fuel cut-off doesn't protect the engine as it's the driveline pulling the engine beyond its limits. I've almost done this in our Si once or twice at less than full song and fortunately didn't do anything but scare the hell out of myself. I've had the experience of taking a chip out of my buddy's Rover TC camshaft doing this in my younger days. It ain't pretty and it ain't cheap!
Click to expand...
So if it's within the gears limits it doesn't matter?
 
Nix said:
Don't over rev downshifting too early. I think that's all you would have to worry about with 1st but that is a pretty short gear. Other than getting going I don't think you would ever really need to downshift into 1st as long as you're moving a little bit.
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First gear goes to like 28-30mph most people just never try it
 
There are other parts that don't need to be overly high in the rev department......... Like spinning the cams in the engine.......... even though your's is a technical question, there is also the question of why would you want to push it?
In most cases taking to the limits of Engine; trans; any part of the drive-train is not going to benefit you in a race, smoothness is the way to win.
 
Monk said:
There are other parts that don't need to be overly high in the rev department......... Like spinning the cams in the engine.......... even though your's is a technical question, there is also the question of why would you want to push it?
In most cases taking to the limits of Engine; trans; any part of the drive-train is not going to benefit you in a race, smoothness is the way to win.
Click to expand...
Maybe I'm going into a turn at like 20 mph and want to rocket out?
 
Manual transmission fluid- use the Honda brand. Others have had horrible lab analysis done using other brands. Stick to the Honda mtf.
 
tacthecat said:
Yep, you may "shock" the driveline but shouldn't hurt anything. Si Max speed in 1st thru 6th at *7100rpm* redline 32.3 51.6 73.7 98.3 127.0 162.9 (however fuel cutoff is at 138 in 6th @6,000 rpm)
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Ty for those numbers so much lol
 
Yeah stick to Honda mtf. I'd say you are due for a change. I auto x my si and there are quite a few corners where your only going 20ish but it still pulls fine in second.
 
I would stick to changing the MTF at 30k intervals, regardless of what the maint. minder says.
 
Please for the love of God and the life of your transmission do not downshift into first unless you're at a complete stop. There is no reason to attempt it even if there was not a lockout as a safety measure
 
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