924Board.org

[Peter]

I just checked the number on my spare 1980 931 snail shell tranny, and according to the Porsche technical book I have a tranny with a "differential lock." I am assuming this is the same as a limited slip differential? If not, what is the difference? Also, how rare are these? I know they were made only for the 1980 year, but any idea on how many 1980 931s came with this. The tranny currently in my 1980 931 isn't a differntial lock tranny.
-Peter

[924RACR]

Yup, that's it! Count yourself as one of the lucky ones!!!

_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[keith]

How strong is that tranny? 250hp/ftlbs survival range, perhaps?

[John H]

The only weak point on these boxes is 1st gear.
It pays to get out 1st as quick as possible and don't change down to 1st unless the car has stopped moving.

If you follow the above the boxes are real strong.
I've raced mine since 1986/7 and the box has done over 260,000 miles. I changed 1st gear dog tooth around the 80,000 miles, out a new second gear dog tooth in at about 120K and reversed the 4 and 5th gear dog teeth and it's still going strong. No othe rwork ahs been done to it - no bearings just teh dog teeth on the gears mentioned and the brake bands associated withthat gear.

[keith]

anyone know if the torque tube used with the snailshell is the same as the tube used with the audi unit?

Would I be able to run the snailshell torque tube with at 951 bellhousing/clutch?

[Pat]

To use a snailshell transmission you need the snailshell torque tube (and shift rods, rear torsion carrier housing)as at the rear where the tube bolts to the transmission as Porsche used a different flange design, instead of having the four bolts widely spaced on an aluminum flange they moved them much closer together because the snailshell doesnt have the vestigal clutch housing like the Audi style gearboxes. But at the front where it would bolt to the engine clutch housing should fit.