912 5 speed

[Bruce.]

The <1969 912 (not the 912E) used the 901 style box. This was amended (in the carrera) at the start of the '70s to use a pull-clutch (gearbox is known as a "911") and then this was replaced by the stronger 915 after a couple of years.

So, any <1969 912 should have the push-to-release clutch (same as bug), operated by an arm that exits on the lower left side of the bellhousing (which is pulled towards the front of the car by the clutch pedal cable). This can be operated by the bug clutch cable with some work.

The gear linkage is a custom fit job. You can either replace the shifter and whole linkage with the 911 parts (needs tunnel fabrication to mount, cut-shut the shift rod, etc). Or you can still use a stock bug style shifter and rod but it will still need some work to set up properly (extend and bend or add a couple of UJs / supports). Plenty of info on the web about the linkage set up.

some useful info:

http://www.germanlook.net/forums/showthread.php?t=10575

and even better (useful gearbox id photos etc).

http://www.germanlook.net/forums/showthread.php?t=9153

[effvee]

Hi, thank you very much. I need to just start

[effvee]

Originally Posted by effvee

Hi, thank you very much. I need to just start

There is also mention of the first gear being weak, is there a fix for the first gear weakness?

[Bruce.]

The issue with the 1st gear is it sits on the end of the gearbox shaft, not between the two main bearings. So if you try to use a 901 box for drag racing, the first gear, being only supported on one side will not last long.

This problem was fixed on the 915. I think they swapped the position of the 5th gear and 1st gear.

For normal road use, up to around 200ftlbs of torque, I don't see this as a big problem.

A bigger issue with some of the 901 boxes, was the diff support. On later 901 boxes, they simplified the parts inside the diff and with wear, parts of the diff can suddenly drop. (!). However, it is not difficult to prevent.
If you remove the bolt from the centre of ONE output flange (do not remove both at the same time!!!), it may be a straight forward bolt or it may have a small nipple on the end. A box which uses nipple bolts has the weak diff. The nipple supports part of the dif and wears away over time, so the bolts need checked regularly and replaced when required. The diff can also be back-dated to remove the weak parts (bits from a 914 box work perfectly).