Alfa Romeo Owners Club of Australia Forum

Technical => 160 Series (90, 75, 164 Sedans) => Topic started by: alfa duk on July 12, 2011, 08:30:15 PM

Title: 75 transaxle
Post by: alfa duk on July 12, 2011, 08:30:15 PM
  Hi guys, do all 3 litre 75 transaxles have the lsd ? Doug
Title: Re: 75 transaxle
Post by: Sheldon McIntosh on July 12, 2011, 08:48:04 PM
They did when new....

It's got longer gearing than the TS LSD.
Title: Re: 75 transaxle
Post by: Duk on July 12, 2011, 08:53:18 PM
Quote from: Sheldon McIntosh on July 12, 2011, 08:48:04 PM
It's got longer gearing than the TS LSD.

Can anybody provide a list of gear ratios for the various 75 gear box and diff ratios?
From what I've picked up over the years the difference between the various 75 TA's is the diff ratios. Notably the Potenziata has a lower diff ratio than the 'pre-Potenziata' 3 litre cars.
Title: Re: 75 transaxle
Post by: Sheldon McIntosh on July 12, 2011, 09:05:26 PM
Do a google search ffs, you can find all the info in 5 seconds.

http://www.alfabb.com/bb/forums/alfetta-gtv6-1975-1986/150737-all-you-wanted-know-about-transaxle-ratios-2.html#post852801

Title: Re: 75 transaxle
Post by: Duk on July 12, 2011, 09:20:43 PM
Numbers.
Title: Re: 75 transaxle
Post by: Paul Gulliver on July 12, 2011, 10:49:07 PM
That document notes the Aust / Swedish Alfa 75 TS as not having an LSD. They might want to phone a friend or check that one again.
Title: Re: 75 transaxle
Post by: scott.venables on July 12, 2011, 10:57:54 PM
I don't think they should have clumped Australia in with Sweden, we didn't get the 1.6, 1.8 or non TS 2.0, and all our 3.0s had an LSD.

Scott
Title: Re: 75 transaxle
Post by: alfa duk on July 17, 2011, 08:19:01 PM
 OK gents, i have the 75 transaxle but it is not lsd.  Is it possible that it is a 75 gearbox in a gtv6 transaxle. Is it a straight bolt up proceedure to swap the box? Doug
Title: Re: 75 transaxle
Post by: Darryl on July 17, 2011, 09:49:10 PM
You do realise it was only the 3L and the TS 75s that were LSD? 2.5 V6 is open.
If you can be a bit more precise on what you have (what transaxle, what car and in particular tailshaft and what the dedion/half shafts are from) you will be able to get some specific advice re swapping. But in brief, the major external variations in alfa transaxles can be summarised as follows (basically working front to rear):

Clutch input / tailshaft flange - one size for Alfetta 2L and 75 TS, another for V6

Input shaft on gearbox - same but sleeve on which throwout bearing slides 2 different diameters (V6 vs 2L)

Clutch push vs pull type (and corrsponding location of slave cylinder etc)

Selector shaft - short version with pin for isostatic shifter on 75s, longer version splined for alfetta type selector

Speedo drive - mechanical gear drive vs magentic pulse electronic - internally different - not a simple swap

Output shaft flanges - all same PCD, but V6 has M10 thread, all 4 cylinders M8

The above is almost right - there were some differences in early Alfettas / GTs (pre about 1978) - I think the output flanges on those were M10...

There is quite a lot of mixing and matching possible (but not everything...).

Title: Re: 75 transaxle
Post by: alfa duk on July 18, 2011, 04:58:32 PM
 Thanks Darryl,  I bought the transaxle and it had 3.0 / 75  written on the gearbox section but it wasnt lsd. Maybe its just a gtv6 box? I will check it out over the weekend. Doug
Title: Re: 75 transaxle
Post by: Darryl on July 18, 2011, 11:20:58 PM
Is it possible the LSD centre has been replaced with an open one? Or is it just worn? How did you tell it wasn't LSD? The pinion + crownwheel are matched and the pinion is on the end of the mainshaft - no simple way to swap the "gearbox" only given the pinion is part of it.