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Posted by: HalfMoon Sep 24 2018, 11:32 AM

I'm trying to determine from this image just what box this is?

Posted by: jcd914 Sep 24 2018, 12:31 PM

That is a 915 trans.
930 is beefier looking.

Jim

Posted by: burton73 Sep 24 2018, 12:32 PM

930 short 4 speed. This is upside down


Bob B

Posted by: burton73 Sep 24 2018, 12:34 PM

Boy Jim they sure look close. My trans is a 930 for 100% sure


Bob B

Posted by: Andyrew Sep 24 2018, 12:43 PM

The tail cone on the 915 is much larger, bloated. On the 930 its very slim.

Posted by: HalfMoon Sep 24 2018, 01:04 PM

Yes, a careful examination of google images reflected this difference in the two.
I wonder if a year made can be guessed at from visual cues?
Hoping the third part can get some numbers from it soon.

Looks to be pre 78 as the case appears magnesium. Post 78 were aluminum, right?

Posted by: HalfMoon Sep 24 2018, 02:03 PM

Number is
915301301OR

Posted by: burton73 Sep 24 2018, 02:55 PM

930 starts with 930 so it must be a 915

Bob B

Posted by: nditiz1 Sep 24 2018, 03:19 PM

Are you selling this 915?

Posted by: HalfMoon Sep 24 2018, 03:49 PM

No.
I might be buying it.

Posted by: HalfMoon Sep 24 2018, 04:22 PM

Research indicates the first number (7) indicates it came from a series 911 car thus making it a 915 trans axle, the second number (1) is the gear ratio's (still trying to determine what that code number means), and the third number (5) indicates it's a 1975 box. The last four numbers are the serial number.

Seems to be some confusion about the second number (1) and the first number (7).

Some say the first number (7) indicated an #03 box witch means it has a 5 sp w. optional ratio's and some say the second number (1) means it's a 5 sp standard ratio's

What those "optional ratio's" might be, I have no clue.

If it's a standard ratio then-
75-79 5 speed
915/40, 915/43, 915/44, 915/60, 915/61,
1st gear 11:35
2nd gear 18:33
3rd gear 23:29
4th gear 26:26
5th gear 28:23
Final Drive 8:31

Anyone verify?

Also from Here´s info from Tech spec book 1st edition (5/1973) for decoding the second number of ´73 transmissions:
(and keep in mind we've already identified this as a 1975 box so the following may be irrelevant)
The 2nd number designation (1) number stands for
"1 five speed standard ratio 5 sp, with oil pump and ground gears (915/00) 0001-5000 OR with shaved gears (915/01) 5001 -9999"
According to the casting number the one we're examining is a OR casting.

Posted by: rgalla9146 Sep 25 2018, 10:09 PM

Go to Blue Sky Motorsports
Click on Tech Info
Full chart of all 915 variants