Convert 4-speed to 5-speed

[Alfaowner]

I've searched the site. But, haven't found anything on this. Seems hard to believe. Am I not using the correct parameters?

In any case, I'm tired of the high revs my 101 Spider has at highway speeds. When I had an MGB, it was a simple task to add an overdrive unit to cut down highway revs. That let me cruise all day long at 70 - 80 mph. And, here in Florida, if you're doing 70, you're holding up traffic. (you know how those "blue hairs", hop heads & smugglers drive)

What is involved in adding a 5th gear to the 101 trans? Or, does it require a trans swap?

Norm Sippel
101 Spider Normale

[emr5503]

Norm,
It can be done. Years ago there was an article on how to do it in the Alfa Owner (IIRC).
Ed

[Mikes4C1300]

Norm,

I agree -- a day of driving at 5500 rpm will leave you a little ragged out to say nothing of what it might do to a near fifty year old engine. This topic has gotten extensive discussion on the 750/101 Yahoogroup. As I recall, it's a rather straightforward swap if you use a 1600 5 speed from a 101 behind a 1300 mill. Later engines and/or transmissions involve the use of a hydraulic clutch which can be a fabrication hassle with the 101 pedal box. Some say a fifth gear will drop right in to a four speed box, others I've checked with say it's a machining hassle too.

I've solved the problem by buying a five speed '67 GTV to drive on interstates, I stick to two lane country roads in my Giulietta!

Mike Hollinger
Atlanta

[VeloceOne]

Greetings all,
To convert to a 5-speed, you need a "barrel" from a later trans, making sure that you use one with the same shifter rod configuration as the 4-speed. You use the bell housing and tail housing from the 4- speed, all you need to do is install the 5th gear bearing cup (or whatever it's called) in the 4-speed tail housing. (the recess is there)
You will also find a "boss" cast into the inside of the tail housing, in line with the shifter rod to prevent shifting in fifth, that needs to be ground down.
There will be some other incidentals to deal with, seals, speedo drive etc, but nothing major.
Been a while, but I think that's the basics, regards Ian.

[Alfajay]

Norm:

You can also put a Giulietta veloce differential into you car, lowering the final drive ratio from 4.56 (normale) to 4.10 (veloce).

Any Alfa 5 speed will fit. Many people (myself included) use a 5 speed out of an early 2L car, because the internal parts are more readily available, and they use bearings where the 1600 5 speeds used bushings. Also the reverse lock-out mechanism doesn't rattle. Some magic is needed to mate the 2L gearbox to the early bellhousing (special bearing and/or seal), but it isn't difficult.

[VeloceOne]

Greetings,
A minor note, yes you can use later "barrels", but as I recall, the later one's had shifter rods that did not protrude past the front of the case.
If this is so, that means the early backup light switch will not function. So if you stay to an early 5-speed (1750 or earlier?) you will avoid this problem. One less thing to deal with.
Regards Ian.

[Alfajay]

Veloce One:

You are 100% correct - that's why I wrote EARLY 2 liter. I think Alfa retained the design with the shifter rods extending through a hole in the bellhousing until the early 1970's. Perhaps the transition to the 131 tooth ringgear and 1.1hp starter coincided with the change in the transmission design. Or, perhaps Alfa introduced these updates randomly. But yea, look for a transmission with the protruding shift rods when doing a conversion to a 750/101.

Mine gearbox was rebuilt and converted by Willy Mueller, of Adria Sportscar in Costa Mesa, Ca. Willy has recently closed his shop, but he's our local guru on 750/101's. Again, there was some trick in using a special bearing and/or seal at the point where the 2 liter mainshaft intersects the 1600 bellhousing.