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> Gear reversing? What gives?
DORIGTT
post Jul 13 2006, 03:04 PM
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Who can 'splain dis to me?

I've read about some gears for sale which are reversed 4th and 5th gears. How does this work? Aren't the gears the same forward and reverse? How does it get assembled and work?

Thanks folks
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Aaron Cox
post Jul 13 2006, 03:12 PM
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lets say you have ratio X:Y

and you flip them on to the other shaft now you have Y:X
(12:34 is NOT the same as 34:12)

you can flip 3rds to 5ths... and 5ths to thirds....

or, 904 second gears to 4ths' and 4ths to 904 mainshaft seconds....


a 911/901 5 speed has 2nd gear attached to the mainshaft, ala, it doesnt come off.. a 904 mainshafts is splined all the way thru.... ala removable 2nd gears
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SirAndy
post Jul 13 2006, 03:14 PM
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QUOTE(DORIGTT @ Jul 13 2006, 02:04 PM) *

Who can 'splain dis to me?

I've read about some gears for sale which are reversed 4th and 5th gears. How does this work? Aren't the gears the same forward and reverse? How does it get assembled and work?

Thanks folks


for each "gear", let's say 5th, you actually have 2 gears, one on each shaft that are together. they have different tooth-counts. the two together give you your gear-ratio for that specific "gear".

however, you can change gear-ration by using gears from other "gears" and by flipping them around, effectively changing your gear-ratio ...

makes sense?
(IMG:style_emoticons/default/smile.gif) Andy
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lapuwali
post Jul 13 2006, 03:21 PM
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You take the gear pair and reverse which shaft they're on. So, you could, for example, take a G gearset (18:33), and flip it around to make a 33:18, which is taller than the tallest off the shelf gearset (ZD, 31:22).
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DORIGTT
post Jul 13 2006, 03:35 PM
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I see!

That's pretty cool! I'm going to see what ratios I come up with in my 914/11 trans.

While we're at it, what tranny's did the M and X etc gearsets come from?
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Aaron Cox
post Jul 13 2006, 03:43 PM
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M and X....

i know X came in a few 912's... maybe M also...

they are kinda short.
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lapuwali
post Jul 13 2006, 03:54 PM
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M is a flipped ZA. X is an overdrive gear (like usually a 5th). It's fractionally taller than the V used as 4th in the 914 gearbox.
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TimT
post Jul 13 2006, 04:02 PM
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While were talking gears, which gearset came with a '75 914?

I need to build a long track box for my car (my 911) the box I built is kinda short AFKQV, I want to build a AFMSX box that I can swap for longer tracks.

I have 2 914 side shifters sitting on a shelf, and a pair of 901 boxes and a few boxes full of gears that I can go through to get the parts I need

After I build a new box for myself, I will be having an "inventory reduction sale" on my spare gearsets... (IMG:style_emoticons/default/av-943.gif)
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Aaron Cox
post Jul 13 2006, 04:03 PM
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QUOTE(TimT @ Jul 13 2006, 03:02 PM) *

While were talking gears, which gearset came with a '75 914?

I need to build a long track box for my car (my 911) the box I built is kinda short AFKQV, I want to build a AFMSX box that I can swap for longer tracks.

I have 2 914 side shifters sitting on a shelf, and a pair of 901 boxes and a few boxes full of gears that I can go through to get the parts I need

After I build a new box for myself, I will be having an "inventory reduction sale" on my spare gearsets... (IMG:style_emoticons/default/av-943.gif)


all 4 cyl 914's were A F N V ZD iirc
al sixes were A GA N V ZA? i think
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Bleyseng
post Jul 13 2006, 04:41 PM
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M and S gears were in 912 5 speed boxes and make for a nice close ratio box for street or AX ing. I kept the ZD for the freeway.
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Dave_Darling
post Jul 13 2006, 04:54 PM
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The Four and Six had identical 1st and 4th gears; the rest were different. 2nd and 3rd were taller in the Six box, 5th was shorter.

http://members.rennlist.com/chuxter/901&915ratios.htm

--DD
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marks914
post Jul 13 2006, 07:50 PM
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I run:

F
Flip V
Flip N
Flip H

Its a nice tall set.
Mark

There is a chart I did a while ago somewhere on the board.
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jimkelly
post Jul 13 2006, 08:04 PM
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chart on aaron cox blog : )

http://www.914world.com/bbs2/index.php?auto...ach&id=3082

gear ratio gear set gear ratios gearsets tranny gears
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Bleyseng
post Jul 13 2006, 09:34 PM
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old pic of flipping 3rd and 5th


Attached image(s)
Attached Image
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Aaron Cox
post Jul 13 2006, 10:32 PM
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QUOTE(jimkelly @ Jul 13 2006, 07:04 PM) *

chart on aaron cox blog : )

http://www.914world.com/bbs2/index.php?auto...ach&id=3082


i forgot about that LOL
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Trekkor
post Jul 13 2006, 11:05 PM
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M-S-X... (IMG:style_emoticons/default/chowtime.gif)


KT
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