Identify My Gearbox?
 

Hello,

My 901 Trans has number 911/01 and 7112281 stamped into the case on the bottom.

Is there any way to tell what the gear ratios are for gears 1 through 5 in this box by the the number?

Thanks,

------------------
John
70/73 RS Spec Coupe

John,

Yep. 1971 model transaxle with standard ratios, it had 1st - 11:34, 3.091, 2nd - 18:32, 1.778, 3rd - 23:28, 1.217, 4th - 27:25, 0.926, 5th - 29:22, 0.759, r & p - 7:31, 4.429:1.

------------------
Warren Hall
1973 911S Targa

Interesting. Thanks Warren!

Does this mean that 4th and 5th gears are effectively "overdrive" gears, in that for every turn of the wheel, the half shafts turn less than once?

In addition, as the first gear ratio suggests, 1st gear is seems very short. Add in the 7:31 R&P, some HP and early car nimbleness, and you are in for some fun.

Second and Third gear are really great fun. I think it is easy to see why the design of the 901 transmission with its "outboard" first gear" seems goofy at first, but in reality makes a great short course gearbox for the frequent 2nd to 3rd and back shifts. 2nd gear is good for 70mph and 3 gear good for 90mph+. Lots of time within those speeds at the track or on the street during spirited driving!

Thanks for the info.

------------------
John
70/73 RS Spec Coupe