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View Full Version : 2nd Gen .756 5th gear



ITS51RX7
03-28-2008, 06:06 PM
I have what I believe to be a .756 5th gear, and what to sell it but can anyone tell me the difference on the tooth count between the .756 and the standard 5th gear.

I just do not what to sell until I am sure what I have.

Here is also a picture

Thanks,

its66
03-29-2008, 09:32 AM
Just divide the smaller tooth count by the larger.(as long you are sure these are 5th gear)

Eagle7
03-29-2008, 12:34 PM
If this page is correct
http://members.aol.com/solomiata/Miata5thGearInterchange.html
then it's 51:23

ITS51RX7
03-29-2008, 02:01 PM
Looks as if the counter gear has 40 teeth and the 5th gear has 18 teeth which makes it a .814 miata 5th gear.
I was told that this set was the .756 Rx-7 5th, I guess I should have done my homework first.
Thanks Marty for the chart, did you get the shock package installed yet ?
If anyone needs a .814 Miata 5th let me know.

Thanks,

Eagle7
03-29-2008, 04:07 PM
Looks as if the counter gear has 40 teeth and the 5th gear has 18 teeth which makes it a .814 miata 5th gear.
I was told that this set was the .756 Rx-7 5th, I guess I should have done my homework first.
Gee that's almost exactly the same ratio. Maybe some more research is warranted.

...did you get the shock package installed yet ?
Yeah, it's on the car, but it hasn't been out yet. That was a sweet package.

C. Ludwig
03-31-2008, 05:01 AM
The tooth count of the OD gearset alone will not give you the actual output ratio. The input shaft is underdriven. That needs to be taken into account when calculating the OD gear output ratio. Unfortunately I don't have the input ratio in front of me to offer up. But the output ratio will be taller than what the OD gearset toothcount indicates.

ITS51RX7
03-31-2008, 06:56 AM
Hey Chris,
Does the chart for gear ratios that Marty posted look correct, or is that chart only for the Miata.
Thanks,

C. Ludwig
03-31-2008, 03:50 PM
Hey Chris,
Does the chart for gear ratios that Marty posted look correct, or is that chart only for the Miata.
Thanks,

AFAIK the chart that Marty posted the link to doesn't exist anymore. When I click on his link it takes me to a page that says it's not there. I know where he is trying to link to and I used to use it as a reference all the time. However the page was taken down long ago.

I'll try to remember to count the teeth on the input side of the trans to get the input ratio today. Multiplying that by your OD set tooth count will get you the actual OD output ratio.

FWIW I am pretty sure the .814 Miata OD set is the same as the .756 RX-7 set but the Miata has a shorter input ratio making the Miata output ratio shorter.

If that set happens to be out of the trans you got from me it is indeed a .756 set.

ddewhurst
03-31-2008, 04:28 PM
To get to the page by Marty try this, http://members.aol.com/solomiata/Drivetrain.html. then under the transmission section reading click on blue high lited "5th Gear Interchange Chart">

Eagle7
03-31-2008, 07:24 PM
I'll try to remember to count the teeth on the input side of the trans to get the input ratio today. Multiplying that by your OD set tooth count will get you the actual OD output ratio.
22:37

FWIW I am pretty sure the .814 Miata OD set is the same as the .756 RX-7 set but the Miata has a shorter input ratio making the Miata output ratio shorter.

If that set happens to be out of the trans you got from me it is indeed a .756 set.
That is what it calculates to.

C. Ludwig
04-01-2008, 04:35 PM
This is what I see when I click that link. I'd really appreciate it if someone would tell me how to view the actual page because I miss it every now and then.

http://www.ludwigmotorsports.com/untitled.bmp

ITS51RX7
04-01-2008, 05:28 PM
Chris,
The link that Marty posted has worked every time I have clicked on it, Your ISP must be blocking you from seeing the page.
I copied the ratio chart and emailed it to you.
The gear set that I have now came from the first RX-7 I had ( Jason Baugh's old car )
I removed the gear set after I torn up the counter gear off the input shaft.

I have somebody interested in the gear set, any idea what it is worth ??
Thanks for info,