I probably shouldn't post this, since I would rather buy next month...

but tenatively I'm looking for a few gears.

anybody have or know someone that has a:

3rd gear size: P

or a 4th/5th gear in size: T

thanks for the consideration

hey gear guru's
would either of these been original equiptment in some obscure 901 box, or are they both race ratio's only.

brant

search the thread on page 2.... '912 gear ratios' - i posted factory gear charts....

T and P.... guessing race only....

S is common.... Seen M/N/O but no P's in person.///

thanks Aaron..

perfect...
just what I was looking for.
it seems that 1968 was the year of the T

but it also looks like the P is a pipe dream.

back to the drawing board (or calculator)

brant

I'm having a "bondo is out of money" sale on the stuff I have, no Ps or Ts tho. See classifieds for details. Remember that you can do some flipping to get ratios you want, but only when you mobe a 3rd to 4th or 5th, or a 4th or 5th to 3rd. (actually, you HAVE to flip them in those cases) For 4 speeds, that changes to 2nd to 3rd or4th, or 3rd or 4th to second.. the 4 speed is just a 5 speed with no first, so second becomes first, etc.

bondo...

I see..
why didn't I think of that first.
I understand flipping gears, but I didn't think of the obvious.

thank you.

so my mythical P gear is really a flipped X

yea!!!!! I have two X gears in my stash....

no I just have to find a 1968 911 t,e,or s that is parting out in order to find my T gear.

how does this group sound:
F/K-L/P/T/W

wooo- hooooo........!!!!!
brant

QUOTE (brant @ Aug 13 2005, 02:37 AM)

how does this group sound: F/K-L/P/T/W

where did you find a K or L mainshaft?

QUOTE (ArtechnikA @ Aug 13 2005, 06:20 AM)

QUOTE (brant @ Aug 13 2005, 02:37 AM) how does this group sound: F/K-L/P/T/W where did you find a K or L mainshaft?

And isn't F a little tall for 1st? That's the stock second gear. It works for V8s, but I don't think it'd be a good first gear for much else.

QUOTE (bondo @ Aug 13 2005, 10:22 AM)

And isn't F a little tall for 1st? That's the stock second gear. It works for V8s, but I don't think it'd be a good first gear for much else.

actually, i think it'd be a nifty gear for a vintage racer that sees airport circuits and doesn't have to deal with standing starts. make for 5 useable gears. your crew can help push you off the false grid...

K or L 2nd is plausible if you have a 904 mainshaft, of course...

where did you find a K or L mainshaft?

K-L is just the ratio between what would be a K gear and an L gear.
Its what the letter assignment would be for a flipped ZD

so the box I'm putting together has a machined main shaft (ala 904) and I'm intending to run my flipped ZD in the 2nd gear slot

-------------------------------------------------
And isn't F a little tall for 1st? That's the stock second gear. It works for V8s, but I don't think it'd be a good first gear for much else.

It will be a good first gear for the race track. We do rolling starts and the only time that 1st gear is ever used is in the pits. If I move F down into the 1st gear location, then that is kinda like having a 6 speed, because I get to have 4 more useable forward gears after F

alot of race cars look for hard to find C gears for 1st, but the F is better/more useable and cheap too

brant

ooopppsss...
posted at the same time as you Rich

Ok, I see. Cool!

ill keep my eyes open for said gears......

find me an AA or a B gear

QUOTE (Aaron Cox @ Aug 13 2005, 10:01 PM)

ill keep my eyes open for said gears...... find me an AA or a B gear

sounds like a plan
brant

I'll check my box, but I'm pretty sure I have a N and O, if that helps.

OK her goes this is my stash as of today.
these are the synchro'd gears letter # of teeth and stamped marking: A 29 IN3, T 29 IN3, V 31 IV, T 27 IV, 34 no other marks got two of them, B 34, T 34, S 27 IV, P 29,
non synchro gears T 23 IN3, X 23 IN, 25 no other marks.....
looks like both ring gears have 31 teeth pinions have 7 just an optical illusion as one ring gear is bevelled on the back side.

Need to build an Autocross box close 1234 and at least ZD 5th. I will sell the rest, most of the dog teeth have had it.

hmm...
I replied, but it must have hic upped.
lemme try again.

Joe, let me do some research and see how many teeth are on each half of the T gear (I mean the 2 seperate gears that combine to make a T)

Also, I can't remember which of the two pieces that the dogs are on for a 4th gear set, but I'll figure it out tonight.... and see if your willing to sell.

groot,
do you know if your O gear is for the 3rd gear space or for the 4th gear space. I think they make one of each and they don't interchange... See my above comment, I'll have to figure out which half of the set has the dog on it for a 3rd O versus a 4th O

thanks
brant

Otto's has reasonable prices on "C" first gears.
I have the last "B" gearset in the world ....and am keeping it.
Now for a 904 mainshaft & LSD and I'll be in biddness.....Otto's has them also....not sure bout the reasonable price bit tho.

I have an M and S, but if I sell them I'll figure out that I needed them, so I'll just hang on to 'em for now. I think that makes sense.

John Walker's Workshop. He beought up some giant lot of tranny parts, a while back.

Joe,

always count teeth, markings mean nothing on alot of 914 gears.....
AA

QUOTE (Aaron Cox @ Aug 15 2005, 07:49 PM)

Joe, always count teeth, markings mean nothing on alot of 914 gears..... AA

Aaron that's what I did that's what I typed. Letter stamped Number of teeth and any other markings.

ask and ye shall recieve....

Joe,

so the T gear is 1:1
26 teeth on each half.
and the 2 halfs probably need to stay together as a set and never get mixed. They wear into each other and I think mixing a "set" would probably be real bad.
so I don't think you have a T in your stash.

I'll have to research more about which part of the set would have the dog attatched to it for a T

normally its easier to say that the associated dog is on the big or the small half of the set, but the T has 2 equal parts to its set.

I'll figure out if the 3rd gear position O or the 4th gear position O has the dog on big or small

thanks all.
brant

can someone answer this question:

regarding a 3rd gear "O"
versus a 4th gear "O"

how do you tell the difference.

I'm only guessing... but usually, the attatched dog is on the first part of the set. The teeth are 23/28 for each type of "O"

I'm assuming the 3rd gear type would have the dog teeth on the 23rd tooth part

and the 4th/5th type would have the dog teeth on the 28 tooth'd part.

Is that correct?

brant

From memory... so it may not be 100% accurate....

For 4th and 5th the driven gear has the dog. For 3rd the driving gear has the dog, which is why you can move a 5th to use for 3rd.... which puts the dog away from the engine. The 5th doesn't actually get flipped, just swapped.... driven to driving gear. The dog still faces down because 3rd and 2nd use the same shift fork.

4th and 5th share a shift fork, so the dog is on the inside of each driven gear, which is why you can't use a 4th gear as a 5th gear, the dogs on on different sides of the driven gear. (I might be wrong on this...., maybe you can flip them and run the gears backwards.)

Thouroughly confused????

To directly answer your question about the "O" gear:
A 3rd "O" would have the dogs on the driving gear.... the one with 23 teeth
A 4th gear "O" would have the dogs on the driven gear.... with 28 teeth.... and so would a 5th gear "O", but the dogs would be on the other side of that same gear

I think I have a 3rd and 4th gear "O", but I'll have to check tonight to make sure.

Kevin let me know what you find.

I always thought that the 4th and 5th were completely interchangeable because the dog was on the same side (forward facing in a teener) and either could slide into the other's space.

but that the 3rd and 4th were not interchangeable (unless flipped)

now I'm good and confused.
brant

QUOTE (brant @ Aug 16 2005, 12:59 PM)

now I'm good and confused. brant

me too....

i forgot to take into consideration the location of the dogs....

Here's what I have... that I'm willing to part with.... most are bare gears.

H, 2nd (hell, I don't even have a 904 mainshaft)
O, 3rd
N, 3rd
N, 4th
M, 4th (I think it's a 4th)
V, 4th (stock)
ZD, 5th (stock)

I don't think you can interchange 4th and 5ths so easily, but there are plenty around here who know more than I about these transmissions. See, the 4-5 slider goes between 4th and 5th, so the dogs have to be located between the 2 gears. So, the dog is on the engine side of 4th gear and on the opposite side of 5th. Maybe you can flip them??

Just remember, not everythinig is swappable from any position to any position.

Also remember that on a 4 spd 901 transmission, you should "think" of it's 1st-4th as being 2nd-5th in relation to our transmissions.

3rd and 5th are invertable....2nd is usually non movable. For AX, you want to be shifting between either 2nd and 3rd or between 4th and 5th, for fastest shifting.

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

James

4th and 5th can be interchanged, but are not invertable. 3rd can be swapped into 4th or 5th positions, but the gear ratio will be inverted (H becomes a very long gear). There is more than 1 "H" gear. Be careful to get the gears that will work in your positions. See the chart in my last post.

I'm waiting on a spreadsheet from a guy to double check my computations.

but here are my long hand figures:

1st choice: F, K/L, P, T, W
Gear 1 2 3 4 5
RPM gap 1,723 1,334 1,054 801
MPH gap 61.5 19.0 18.0 16.7 14.2
Max mph 61.5 80.5 98.5 115.2 129.4


2nd choice: F, J, O, S, V
RPM gap 1,529 1,284 1,075 772
MPH gap 61.5 16.3 16.6 16.3 13.1
Max mph 61.5 77.8 94.4 110.7 123.8


brant