Four Speed Conversion?

Jim Chambers · 08-05-2003, 08:11 AM

New to this board but not to 912's. Owned my first of 5 in 1970.
As I recall a 4 speed was standard and 5 speed optional. Most had the 5. I am thinking about converting to a 4. Does anyone know what is involved? Assume tranny is a straight bolt in. What about shift linkage? Anyone have one in a car or trans. for sale?

Morrie · 08-05-2003, 11:17 AM

should just bolt right on Jim... linkage should not be affected.

Sweetheart912 · 08-05-2003, 03:21 PM

I's suggest making sure your mating flanges are a match - nadella to nadella or llobro to llobro. If you have a later 902/5 I suggest trying to mate to a 902/4 for the swap. If you have the 901/5 try to find a 901/4 is my suggestion BUT the later & improved 902 will also work fine. Linkage etc is a non issue and I think (but verify this) dimensionally the mounting braces are the same but a different shape depending on early or late. Cables such as speedo & back up light are same, and there are variations between early & late clevis pins/clutch cables but NONE of these are of anything that are monumental nature or should stop your conversions. It is not difficult. Go for it. Good luck.

Morrie · 08-06-2003, 04:43 AM

Maybe I missed something but I believe all 912s 65-69 had a 901.... or am I mistaken..... always learning....

Griznant · Griznant's Garage

Forgive me if I seem out of line, but I happen to own a 4-speed '69 and I have to ask why in the world would you really want to do this?

I don't know what sort of drug the engineers were on when they put the ratios together for this trans, but it flat out SUCKS in every aspect of driving. 2nd is too tall to power out of tight turns, but 1st is too abrupt and short. The ratios don't keep the engine in the power band and 4th is entirely too short for decent highway cruising (unless you like 4000rpm for mile after mile), and I know this is the same as 5th gear in the 901 5-speeds.

I put the Type 4 in my car with the 4-speed and even though it is truckloads better than the 1600 was (much more low-end torque), it is just a terrible choice of ratios.

Maybe others have a different opinion, but I've got a 914 gear cluster (short 1st-4th and taller ratio 5th, .71 vs. .79) ready to go in the box this winter, and I can't wait.

However, if you do want to do it, just make sure the axles bolt up and the rest should be a straight swap over.

Later,

G

Morrie · 08-06-2003, 09:22 AM

see how easily i confuse! i was thinking 915, not 902...
duh

Jim Chambers · 08-06-2003, 10:15 AM

Clearly I need to do more gear ratio research. However, if I
understand G correctly, 5th and 4 speed 4th are the same. If that is so, highway cruising rpm is the same. Porsche used 4 speeds and 1600's in a whole bunch of 356's and they performed pretty well. Did the final drive ratio change with the 901? I am after the 356 "feel" in a 912.

ROTHKO · 08-13-2003, 08:14 AM

JIM, I HAVE A 4 SPEED BOX IN GOOD ORDER AND HAVE SERIOUSLY TOYED WITH THE IDEA OF A FIVE. WANNA SWAP? ONLY PROBLEM IS THAT YOU WILL HAVE TO SWIM HERE TO GET IT!

itsofishel · 08-15-2003, 11:36 PM

Hey Jim I live in Tigard and will be dropping my motor trans to work on the heads. I have a 901 4 spd in my 69 and would swap if interested.

pjv911 · pjv911's Garage

I have a super nice 902/0 four speed(67` 912) ready to bolt in. Its Yours for $450.00+ shipping from new york. UPS would ship it with no problem.

Kurt Williams