Alfa 75 transaxle

[Biba69]

This falls mostly under curiosity but is there someone importing the Alfa 75 transaxles used in conjunction with the Twin Spark engine? All I've heard is that it is the ideal combination if someone is installing a TS in their 116.

I'd also be curious if it bolts right up to a 116 DeDion or if some reason the DD is different on the 75.

And one more question, what would be the ideal driveshaft for this installation - also taking into consideration availability of the donuts.

OR...would a rebuilt 116 transmission/transaxle be just as good as a 75's or close to it?

Biba

[BigSwede]

Ideal? For what?

[marks alfetta]

I happen to be doing the Transaxle swap to my Alfetta as we speak. The Alfa 75/Milano gearbox bolts straight in. The problem is the isostatic gear shift. There isn't enough room under the Alfetta to accomodate it. Your choices are to swap it with the Alfetta gear selector rod or do a bit of panel beating on the floor pan. I haven't decided which I'll do as yet.

By the way the Alfa 75 gear shift rod (The rod from the gear lever to the gear selector rod on the gearbox) is longer than the Alfetta and it is secured to the Gear selector rod by a pin. The Alfetta Gear shift rod is connected to the gear selector rod by a nut.

I'm no expert and this is my first conversion. So its trial and error for me. Others may know better.

[Biba69]

marks alfetta, thanks for replying. First, is your an Alfetta as we in the US consider one - 4-cylinder, made from '75 to '79 and has four wheel studs? Not to go off on a tangent but at least in the US the Alfetta name lasted for only '75 and '76 then switched to being called an Alfetta GTV (at least in the coupe version). Then we got the GTV6 which we in the US do not refer to as an Alfetta. Just verifying we're on the same page, so to speak.

In your case I'm assuming you had no trouble getting a Alfa 75 gearbox. Can I assume you're installing the complete transaxle? Are you possibly using the complete DeDion unit for the transplant? Have you installed a Twin Spark in your Alfetta? Meaning, I'm curious as to why you're making the switch? What drive shaft and donuts you will be using?

My situation is I have a '75 Alfetta GT that I've just installed a fresh engine with 10:1 pistons. However I have a TS and would love to have more low down grunt. My transaxle needs rebuilding and I'm debating whether to have a spare Alfetta transaxle rebuilt, including lightening the gears, or IF I do decide to install the TS in the car, am I better off getting an Alfa 75/Milano transaxle for it? Are the Alfa 75 and Milano transaxles identical or just 'similar' - if you should happen to know.

Yes, I read that you don't consider yourself an expert so what I'm really trying to find out is if the 75's transaxle was just handy, or if you purposely got one for you Alfetta - and if the latter, why?

Biba

[BigSwede]

Do it, TS engine and TS box I mean. LSD and better gearing. Swap input selector shaft to use the old linkage, rebuild the linkage with new bushing and such. The output flanges should AFAIK match between the Alfetta and TS boxes, the V6 and turbos are different though.
Your biggest problem will be the speedo, mech v. electric sender.

[marks alfetta]

Biba69 I think we are on the same page.

In Australia the Alfetta seems to have followed the same path as it did in the US. We also had the Alfetta GT 1.8 litre 4cylinder from 75 to about 76 and then the Alfetta GTV 2 litre and so on. I, like you, also have a 1975 Alfetta GT and this is the car I am restoring with a bit of an upgrade to an Alfa 75 twin spark engine and gearbox.

I was lucky enough to purchase a 1988 Alfa 75 twin spark which was an insurance write off and not to badly damaged at a reasonable price. So this is the donar car for my project.

So far I have been able to ascertain that the rear DeDion on the Alfa 75, while it seems to have the same spring and shock absorber points, is wider wheel to wheel than the Alfetta. I'll be sticking with the the Alfetta De Dion which has the 4 bolt stud pattern unlike the 5 bolt stud pattern of the Alfa 75. The Alfa 75 rear axle half shafts are also longer than the Alfetta. The watts linkages appear to be the same. Springs are different (Alfa 75 are taller) but the rear sway bar is the same.

As yet I haven't pulled out the drive shaft from the Alfetta to compare to the Alfa 75 but I am hoping its the same as I would prefer to use it to ensure that everything remains in balance.

In respect to the fuel tank the primer pump (inside the tank) of the Alfa 75 will fit into the existing hole on the Alfetta tank and is secured in place by the same means. Unfortunately in this process you lose the Fuel sender relay from the Alfetta tank and an alternative needs to be sourced. I was able to get a universal fuel sender relay with the correct circuit board to work on the Alfetta guage. This means though an additional hole has to be cut into the tank (after it has been defumed) to accomodate it. There may be alternative solutions but this appeared to be the easist for me.

Hope this helpd and good luck.

[marks alfetta]

Forgot to mention the Alfetta Gearbox and engine in my car were both stuffed and were going to cost a lot to repair. Swapping to an Alfa 75 was a cheaper option, hopefully. Also as BigSwede mentioned better gearing and LSD was on offer.

Alfa 75 or Milano. Thought they were the same. Milano being the name they gave the car in Europe? Could be wrong.

If you're putting a TS in. Do you have the wiring that goes with it? Might be a problem if you don't.

In respect to the speedo, I haven't gotten to that as yet. Wondering if BigSwede would know if the later model GTV's came with electronic speedos and can you swap the mechanicals from the Alfa 75 Speedo to that?

[Biba69]

Thanks to both you marks alfetta and Mats for this information. It does answer most of my questions. A fellow ABBer who lives in California has installed a TS in his Alfetta. He originally had a fuel delivery problem but solved it by installing an aftermarket fuel pump. I will add that one of his biggest problems was lack of room between the front of the engine and the underside of the hood. He ended up cutting out a section of the 'reinforcement' panel to resolve that issue.

In CA they have strict smog laws, but the cut-off date for needing to have ones car tested is from '76 on. Meaning my '75 is exempt. True, if you install a later engine, it must meet all of the pollution standards for that engine - except I'm not planning on mentioning it if I make the swap.

Actually it is the other way around in that the Alfa 75 is European and the Milano is what the US got. If either one of you have information regarding the transmission's gear ratios and the final drive for the Alfa 75 I sure would appreciate having that info. I then want to compare it to the gear ratios/final drive of US Milanos. However all of our MIlanos came with the V6.

If you still have the original '75 Alfetta driveshaft I do know you'll want to get rid of it. When I rebuilt the engine for the Alfetta I used one from a '78 Alfetta and then used its beefier driveshaft. The front donut for the '78 driveshaft slipped right on the studs of the TS but certainly wouldn't have on the 1975's studs. I will add that overall the 78's driveshaft was at least 6 mm's shorter than the one original one from the '75. I had to shim all of the donuts so it would then connect to the ('78) three-eared flange without distorting the donut. And that was with the transaxle adjusted all the way forward.

I must admit I haven't gone through the thought process regarding the gauges.

Mats, could you explain, "The output flanges should AFAIK match between the Alfetta and TS boxes...?" I don't know what AFAIK is and when you say output flanges are you referring to those for the axles?

Biba

[Craig]

G'Day Biba,

It mostly comes down to what you want/will be happy with. Way back when I had my '74 Alfetta I don't remember being unhappy with the gear ratios or lack of an LSD, I seem to remember spending most of me time in 3rd anyway.

So whether you change the gearbox or not should probably be base on how happy you are with the current ratios/diff and/or if you just want to.

That said, the ratios in Milano's are the same as the TS, the diff ratios in the Silver, Gold and Platinum are the same as the TS with the Platinum having LSD.

The Verde has a taller diff (3.54) with LSD.

The clutch setup on the V6's differs but I'm not sure of the details, the input shaft spline may be an issue but I don't really know.

Mat's is referring to the axle flanges but again, I'm not sure of the details.

[1978alfa]

TwinSpark gives the Alfetta GT the power it should have had to begin with. I love mine. I had to cut part of my hood to make it fit. Engine is trouble free.

-Clark

[Alfar7]

The Verde/Plat ratios are not always better. It depends on usage, and their tall 3rd 4th & 5th are not what 4 cyl. cars work well with. Unless you are looking for economy .
See below. I have posted this many times. The 6cyl boxes are much stronger constructed and use bigger bearings, and pinion/main shafts. The input shafts are as well different designs, but the gears can be modified to work in either case. It takes machining however.

Gear Comparisons for 116 Transaxles
Note: given as: actual gear ratio / overall ratio based on R&P


1st 2nd 3rd 4th 5th
Verde 3.54 stk /overall 2.87/10.18 1.72/6.11 1.23/4.36 .95/3.25 .76/2.69
Economy tall gears

Alfetta Gears with 4.1 R&P 3.30/ 13.53 2.00/8.20 1.34/5.49 1.03/4.22 .83/3.40
Better performance for 4 cyl or V6

Alfetta with 3.54 R&P 3.30/11.71 2.00/7.10 1.34/4.76 1.03/3.60 .83/2.94
More performance in lower gears, fuel economy about same as stock Verde in 5th

GTV6 gears & 3.54 R&P 3.50/12.39 1.96/6.94 1.25/4.43 .95/3.25 .78/2.76

Mod. Verde, 4.10 R&P
with Alfetta 3rd, 4th. 5th, 2.87/11.77 1.72/7.04 1.34/5.49 1.03/4.22 .83/3.40
Closer Ratios better performance good 5th economy Requires moderate machining & set up. My favorite setup especially if used with RJR .95 5th gear for a 3.89 overall ratio for hot street short track racing

RJR RaceTransaxle
mix of 116 type gears
with 4.10 R&P 2.00/8,20 1.23/5.04 1.03/4.22 .95/3.90 .83/3.40
Alternate 1st 1.72/1.96/2.0, alt 2nd 1.23, 1.25, 1.34. All input shaft gears pressed & welded. Expensive to build.

[daz]

My situation is I have a '75 Alfetta GT that I've just installed a fresh engine with 10:1 pistons.
Biba[/quote]

Why oh why do you want to change your original very rare car and install a relativley modern engine into it.
sureley its worth a lot more as it is. the 1.8 alfetta gt is a peach in its own right. if you want a modified gtv then get a newer one and convert that.
I have a gtv6 and would give my left testicle for your 1975 gt

[Biba69]

daz, I don't know what the situation regarding the value of Alfetta GT's is in England, but they frequently go for $200 for a complete non runner. My '75 does have a bit more value in California since (at least for now) it is the last year which is exempt from being required to be 'smog tested'.

This car is my one and only daily driver and I would simply like more low down torque, along with a faster shifting gearbox (with ideal gear ratios). Also I've been going without a working A/C for many years and have installed a later 'arrangement' for the compressor and alternator in my '75. The car came with factory air and when working would drop the rpm at idle about 700 rpm. Before I installed the A/C / alternator brackets in my Alfetta I 'tried them on' the TS. With only a small amount of work it could be made to fit the TS. I feel the TS could handle the extra drag when the compressor comes on. Do keep in mind that for at least six months out of the year, A/C is virtually a requirement here in CA.

Even though Alfetta GT hoods (bonnets) are not hard to find I've thought about getting a GTV6 hood for it rather than cutting a portion out of the structural piece under the hood to give room for the front of the TS.

Essentially the car could be returned to stock if someone desired to do this. Though stock includes Spica fuel injection, 4 into 1 cast exhaust manifold, air pump, and catalytic convertor. The latter parts essentially strangled the stock engine. Mine has had twin 40 DCOE's and 4 into 2 exhaust since 1980.

I simply want a smooth running, more powerful engine, quicker shifting, and a more comfortable interior. Yes, I'm old.

Richard, thank you for posting the gear ratios. It saves me from hunting around for them. Off hand do you know if the Alfetta gear ratios changed from year to year? I'd like to keep my stock '75 transaxle in the car while I build up a complete DeDion/transaxle so I can relatively quickly switch them. If I stick with an Alfetta transaxle, I then have the choice of using either a '78 or '79 transaxle/gear box to be rebuilt. Is one year better than the other?

Biba

[Ennio]

I´ve been reading this thread with great attention and I wanted to know if I could install LSD from a Milano/75 to my stock 82 alfetta-gtv (gtv2.0) transaxle?
Is it possible? If so, could I mantain my aprox 4.10 rear-end? If not, is there a very close ratio with LSD?

Regards

[slyalfa]

Biba69 with a electric-FI it should keep the same RPM with or with out AC on. there is a small valve that bypasses the buterfly and when the AC kicks on the valve opens, adding the power needed to make up for the AC. there is a adj. on it so you can fine tune it.
that is the L-jet system the newer system have a PWM valve that the ECU can open as much as is needed and the ECU just trys to keep the RPM at the set point. with the newer systems the RPM will drop a bit when the AC comes on but then go back to the set point as the ECU make the changes.