Alfa Romeo Owners Club of Australia Forum

Technical => 160 Series (90, 75, 164 Sedans) => Topic started by: MD on June 06, 2011, 08:29:21 PM

Title: 75 Automatic ratios question
Post by: MD on June 06, 2011, 08:29:21 PM
Hi,

Does anyone have any information regarding what ratios that are used in the 75 series automatics?

What ever info you do have is very much appreciated.
Title: Re: 75 Automatic ratios question
Post by: pep105 on June 06, 2011, 08:54:23 PM
MD,

I got a two road tests and an original Alfa 75 owners manual that will answer your questions I just need to get it out of the attic, might try tonight once the little tackers have gone to bed

Cheers
Pep
Title: Re: 75 Automatic ratios question
Post by: MD on June 06, 2011, 10:02:34 PM
Pep,

You are a gentleman and a scholar. There's not many of us left.. :)
Title: Re: 75 Automatic ratios question
Post by: Sheldon McIntosh on June 06, 2011, 10:41:50 PM
Top  1.00
2nd  1.48
1st   2.48
Final Drive   3.154

I was actually scrolling through some roadtests looking for something unrelated when I came across this, and remembered you'd posted.

From here...http://www.flickriver.com/photos/triggerscarstuff/sets/72157615591448627/ (http://www.flickriver.com/photos/triggerscarstuff/sets/72157615591448627/)
Title: Re: 75 Automatic ratios question
Post by: pep105 on June 06, 2011, 11:55:37 PM
Well just crawled out of the attic.......Sheldon looks like you beat me to it

So ill bombard you with useless information on the 75 slushbox  2.5

Yep thats the gear ratios so as a result speeds in gears are when floored in drive

    Km/h/rpm      Ratios/km/h per 1000 rpm
1    79/5800              2.48/13.7
2   129/5600             1.48/23.0
3   200/5900             1.00/34.0 

Test car got 0 - 100 in 10.9 secs and 400m in 18.0 sec

Wheels said they enjoyed it more than the manual in Sydney traffic and while off the line its slower they reckon after 20 km/h
its as quick as the manual. Also runs a different exhaust to make it quieter............

Sorry too much info in the end  :)

Cheers Guys

Quote from: MD on June 06, 2011, 10:02:34 PM
Pep,

You are a gentleman and a scholar. There's not many of us left.. :)

We're a dying breed MD  ;)
Title: Re: 75 Automatic ratios question
Post by: MD on June 07, 2011, 08:22:58 AM
Thank you guys. This is the perfect example of why one should get along with members of the Forum. When you need info, often you can't even buy it ! This is rare info for a semi rare car.

To be honest, my wife owns a 75 auto and it is a good car around town for her. I take it out occasionally on country runs to give it a tune up. ;D It behaves exactly as road tested.

All that aside, the info is not actually for me. I am trying to help an Alfisti in Finland who is a very good friend and so the spirit of Alfa camaraderie lives on..


Cheers.
Title: Re: 75 Automatic ratios question
Post by: MD on June 07, 2011, 09:49:12 AM
Hi Paul,

The acquisition of a 75 auto for the missuz started with me just trying to buy the ZF automatic transaxle gearbox. She had a very good Alfetta Sportiva at the time which I had put a lot of work into but she hated the manual shift around town. Just before I bought a gearbox, I had a chat to Richard Anderson from Avanti Spares in Brisbane. He advised against it as the ratios were too tall and not enough of them for a 4 cylinder banger. So that's how I moved onto the car she has now.

I have a friend who runs an automatic gearbox only workshop and he thinks the automatic transaxle is a simple ZF unit, tough and easy to work on. It's only a three speed job so the auto is not that fuel efficient but in my case that's the least of my concerns but others should keep that in mind.

There is a benefit of course buying a used automatic. They are usually much more kind to the engine and drive train. So if it is an auto you're after, it is probably in better nick than it's manual equivalent for the mileage as a general rule.

A great car for you Paul. Minimal confusion. There's only two pedals.  ;D ;D
Title: Re: 75 Automatic ratios question
Post by: aggie57 on June 07, 2011, 10:45:17 AM
My wife had one a few years back as well and I have to say I enjoyed driving it. As you say Paul the transmission is much easier on the drivetrain than a manual but you do need to give bit a bit of a hurry up to get it moving. if you change manually, which Alfa had sorted out nicely, it can get along nicely.

The fuel tank is pretty small though and with the 3 gears and the tall final drive they're pretty thirsty compared with a manual. On the other hand they were well equipped including tilt/slide roof.

The story I heard about the transmission was that a 4-speed wouldn't fit and the 3-speed couldn't handle a 3-litre engine. So we ended up with a 2.5 3-speed rather than the preferable 3.0 4-speed.