Tall Fifth gear question? Options

[r_towle]

Hi,
I have read that flipping one of the gears from a spare tranny and putting it (the pair) in place of the 5th gear will give you a taller than stock fifth gear...

So, I am the kind of person that needs to see a picture.

Does anyone have a pic that shows which gear to flip.

What I would love is a pic of a stock gear set, and then a pic of the new one...showing the flipped gear.

Thanx
Rich

[bondo]

This only works if your spare transmission has the gear you want. There is nothing in a stock 914 trans that can be put in the 5th spot to give you a taller 5th. The common swap comes from the second gear of a 912 4 speed trans. It's an H gear, and is in the spot that a 914 trans would have 3rd gear, but it's a 2nd gear ratio (because it's a 4 speed)

The other gear some people use is an HB, not sure what trans that comes from.

You can't swap the F second gear into the 5th gear spot because that gear is part of the mainshaft. (whatever gear is in that spot is always part of the mainshaft unless you have a 904 mainshaft... in a 4 speed, 1st gear is in that spot)

One more note about "flipping".. on a 914 trans, gears have to be flipped (reversing the ratio) if they go from 3rd to 4th or 5th, or from 4th or 5th to 3rd. You can't move a 3rd to 4th or 5th without flipping it, and you can't move a 4th to 5th or vice versa and flip it. Subtract 1 from those numbers for 4 speeds.

Man, I hope all that makes at least a little sense. (IMG:style_emoticons/default/smile.gif)

[jd66921]

This only works if your spare transmission has the gear you want. There is nothing in a stock 914 trans that can be put in the 5th spot to give you a taller 5th. The common swap comes from the second gear of a 912 4 speed trans. It's an H gear, and is in the spot that a 914 trans would have 3rd gear, but it's a 2nd gear ratio (because it's a 4 speed)

The other gear some people use is an HB, not sure what trans that comes from.

You can't swap the F second gear into the 5th gear spot because that gear is part of the mainshaft. (whatever gear is in that spot is always part of the mainshaft unless you have a 904 mainshaft... in a 4 speed, 1st gear is in that spot)

One more note about "flipping".. on a 914 trans, gears have to be flipped (reversing the ratio) if they go from 3rd to 4th or 5th, or from 4th or 5th to 3rd. You can't move a 3rd to 4th or 5th without flipping it, and you can't move a 4th to 5th or vice versa and flip it. Subtract 1 from those numbers for 4 speeds.

Man, I hope all that makes at least a little sense. (IMG:style_emoticons/default/smile.gif)

Nope (IMG:style_emoticons/default/WTF.gif)

[TimT]

Rich, I just checked, I have two extra "Z" gearsets lemme know if interested

I also have M,S,O,P, and a bunch of 914 gears that I have to count teeth on.

[bondo]

This only works if your spare transmission has the gear you want. There is nothing in a stock 914 trans that can be put in the 5th spot to give you a taller 5th. The common swap comes from the second gear of a 912 4 speed trans. It's an H gear, and is in the spot that a 914 trans would have 3rd gear, but it's a 2nd gear ratio (because it's a 4 speed)

The other gear some people use is an HB, not sure what trans that comes from.

You can't swap the F second gear into the 5th gear spot because that gear is part of the mainshaft. (whatever gear is in that spot is always part of the mainshaft unless you have a 904 mainshaft... in a 4 speed, 1st gear is in that spot)

One more note about "flipping".. on a 914 trans, gears have to be flipped (reversing the ratio) if they go from 3rd to 4th or 5th, or from 4th or 5th to 3rd. You can't move a 3rd to 4th or 5th without flipping it, and you can't move a 4th to 5th or vice versa and flip it. Subtract 1 from those numbers for 4 speeds.

Man, I hope all that makes at least a little sense. (IMG:style_emoticons/default/smile.gif)

Nope (IMG:style_emoticons/default/WTF.gif)

Ok, I'll try again.

First paragraph: You can only get a taller ratio if you flip a gear that gives you that ratio. an H gear is an 18:32 ratio, and flipping it gives tou a 32:18 ratio, which makes a tall 5th gear. I forget what the stock 5th ratio is, but charts are available here, search for "ratio". Figure out what end ratio you want, and you'll know what gear you need to flip. You CAN flip a stock 3rd gear into a 5th gear, but that'd give you a shorther 5th, not taller.

Third paragraph: The second gear in a 914 trans (which would give you a taller 5th if flipped) isn't going anywhere because one side of it is machined into the mainshaft.. all one piece.

Fourth paragraph: Second and third have the sliders/syncros on the pinion shaft. Fourth and fifth have the sliders and syncros on the mainshaft. It has to stay that way because that's where the shift forks are. In order to move gears from slider on the pinion shaft to slider on the mainshaft (or vice versa) you HAVE to flip the gear, which means you put whatever gear of the set that was on the pinion shaft onto the mainshaft, and whatever gear that was on the mainshaft onto the pinion shaft. For reasons previously stated, second gear isn't going anywhere. On a 4 speed it's the same, but it has only 4 speeds, so it's first that isn't going anywhere, and 1st and 2nd have sliders on the pinion shaft, 3rd and 4th have sliders on the mainshaft.

[propricer]

Tried to add a pix of my tall box while it was on the bench but they rejected my single downsized 382K pix ... if interested, send an email to ed.ducey@gmail.com

[Aaron Cox]

rich, sounds like you need an H, HB or HA gear (second gears in 4 speed boxes - thus removable)

lets say an H is an X:Y ratio. by flipping it, you get Y:X