Alfa Romeo Forums banner

1 - 12 of 12 Posts

·
Registered
Joined
·
4,606 Posts
Discussion Starter #1
I need some clarification, please. Is the 2600 transmission the same as a 101/105 5 speed other than the bell-housing and input shaft?

Also, where can I find one? A fellow contacted me about a gearbox I have for sale as he needs one for his restoration.
 

·
Push hard and live
Joined
·
9,137 Posts
The rear housing of a 2600 does not have the boss at the bottom to house the support bushing. So, just the chunk in the middle, with a different input shaft, can be made to work.
 

·
Registered
Joined
·
4,606 Posts
Discussion Starter #3
I found your older post about the differences between the 102 and 106 gearboxes. A great read. Do you have a photo of the rear housing as I am not clear as to how the back end is supported? It is decades since I was last under a 2600.
 

·
Push hard and live
Joined
·
9,137 Posts
No pic handy at the moment. I’ll try to describe again.

The rear mount for the 2000 and 2600 is a long bolt that goes through two bushings mounted in the bell housing. This bolt is then secured into a transverse structure that is bolted to the body shell under the transmission.

The rear mount for 101s, 105s, and 115s is a bolt that fits through a single bushing mounted at the bottom of the tail housing. This is then attached to a similar transfers structure mounted under the rear of the trans.
 

·
Richard Jemison
Joined
·
7,170 Posts
The 106 transmission is as you described, as to the internals as gears (tooth count) are the same as early 101 5 speeds, the input shaft is longer. Other than the missing 5th gear set, gears from the split case 4 speeds main shaft can be used as replacements.
Gears from later 5 speed 105/115 have different tooth counts on the gears.
 

·
Registered
Joined
·
4,606 Posts
Discussion Starter #6
JR, I read an earlier thread about trying to make 102 gears work in a 106 and they don't mix. Your advice on the early 4 speed is good information. Thank you.
Don, I have a better picture of what that looks like with your description.
Will the bell and tail housing fit onto the 101 center without modifications?
 

·
Push hard and live
Joined
·
9,137 Posts
While I have a general idea of the mixing concepts, there are people with more specific experience than me. Maybe Jay Nuxoll will appear and add his 150 years of experience.

It can get a little murky, as there have been “expert” opinions that disagree.

For instance, I am currently driving with a 2600 transmission in my 1959 2000, fitted with an FNM 2300 engine. The 2600 box was modified with a 2000 bell housing, input shaft, and output shaft. This was motivated by the 2300’s significantly higher power output, and I wished to have the 2600’s taller 5th gear.

The 2000 uses a four-finger/eight hole output giubo, and the splines for its clutch disk are different than for the 2600. Also, SOME 2000/2600 bell housings are drilled to mate up to both engines, but I’ve never had one of those, so had to use a purely 2000 bell housing.

Meanwhile, when we were doing the conversion a well known Alfa “expert” swore the input shaft gears would not correctly match the layshaft gears.

I’ve got about 10,000 miles on the combination so far, with no complaints.

So, any guidance you get should be taken as well intended input, but not necessarily the word of god.
 

·
Registered
Joined
·
175 Posts
I am not a Alfa gearbox expert, but Mike Besic just rebuilt my 2600 gearbox and converted it to late model 2 Liter shift rods, forks, sliders, roller bearing 5th gear and moly synchros. The late model parts are very "heavy-duty" compared to the "101 style" pieces used in the 2600 gearbox. He retained the bellhousing, input shaft, some gears, countershaft, output shaft and rear tailhousing. He used a late model center case to get the shift rods, etc. You end up with a gearbox that looks exactly identical externally, has very strong parts, uses any modern gear oil and shifts beautifully.
 

·
Registered
Joined
·
1,295 Posts
I had exactly the same done as DWR46. I gave A 106 box and an excellent later 105 box to an alfa gearbox expert and got back an excellent 106 box full of 105 parts. I never new the detail but it was probably the same as previous post
 

·
Registered
Joined
·
2,521 Posts
Hi All,

I have 102 and 106 gearboxes in parts and also 2300 rio bellhouse

you can use the long direct drive axle for conversion /rebuilding by using an 105 /115 gearbox

for info PM ( [email protected] )

see :


rgds Franco
 

Attachments

·
Registered
Joined
·
1,481 Posts
Well, I have used a 105 gearbox mated to 106 input shaft (a 102 input shaft does not fit) on my two liter. But using such a box on a two liter ends up with a six hole type guibo, i.e. metalastic or rubber donut, which doesn't fit with the two liter driveline. When I used a 2600 driveline I discovered the rear universal joint is not a perfect fit (a minute amount too much diameter) so I had to grind the ends of the "x" piece carefully. The other problem was that I had change the speedo drive on the end piece to match the out drive used on the two liter -- must have both sets the same or they eat each other -- because the 105 gearbox speedo drive is not calibrated for the infamous 165x400 two liter or 2600 size tires. Of course the gearbox tower end casting pieces are easily changed so the rear ring on the mount of the 105 transmission is not hanging down looking strangely out of place on a two liter or 2600. And finally, remember that Alfa always has parts from previous usage in other vehicles. For example, Look at the 102 of 106 parts books to see how many 10306 or 10308 parts numbers (from the two variations of the 1900 engines) are used in those newer vehicles.

Ready for this? I have also used a two liter box on a 2600, but I had to get a Giulietta end piece with same spline as two liter end piece but with three fingers. Naturally the speedo drives had to be mated correctly (used the two liter drive on the giulietta end piece). Worked fine..

Finally, with all respects to those who say transmission fluid does not matter, I must still tout the old Dentax 90 (the old formula now with a different name from Shell -- see prior posts on the BB) for use with non moly synchros if you want to avoid the grind that finally comes about. The heavier dentax 90 is not as slick and slows down the gears to make shifts less grinding. A word to the wise.
 

·
Push hard and live
Joined
·
9,137 Posts
And... the version I’m using is a 2600 box with a 2000 output shaft (for the 8-hole giubo), a 2000 bell housing and 2000 rear gearshift tower housing. The 2600 input shaft still works in the 2000 clutch.
 
1 - 12 of 12 Posts
Top