ok ive got an 83 gtv6(2.5)...what transaxle will go in without the need to modify or change anything?....re-useing my existing clutch, brakes, ect
about all i do know is that the 85+? changed the shift linkage and requires a hump in the floor right?
will a alfetta 78/79? survive behind a 2.5? is it the same unit save final drive ratio?
i blew my diff in my 83 and have located a 86? and a 79? unit.....as well as haveing my project milano that i "could" pull the transaxle out of but it would have to be replaced with another unit anyway so why bother yanking it!
Put a 75 Twinspark box in it and reap the benefits- the 4.1 diff ratio will keep it nice and spritely, and will go nicely with the torque delivery of the 2.5, the longer 1st and 2nd gears will also work nicely, the isostatic linkage is much better, and the LSD means less chance of diff breakages, and you'll still be able to get home if you drop a driveshaft.
I used a 2.0 alfetta box behind a 2.5 V6 for years but be warned - drive it a little gently. They differ from the V6 and twinspark ones in one simple way - the alfetta ones only have 2 diff planetaries (spider gears) where the V6 & TS ones have 4 planetaries. Eventually I shattered a few teeth of one of these planetaries and it all didn't work so well after that (not as bad as letting all of the smoke out of it though).
Like Jules said - go the TS if you can get it. Better ratios, 4 planetaries and an LSD, what more could you want.
is the iso shift setup from the 86+ boxes a better setup?..i dont mind so much modding the car to accept it...fact is ive not spent enuf time under the cars to know exactly what the diferances are......even tho i have a 87 milano sitting here
ive got no complaints about how the 83 non iso shifts other than being sloppy even after i redid the whole system...course the iso on the milano is just as sloppy....but that transaxle is destined to be cable shifted but thats another story entirely....
the milano will gladly donate the iso linkage to the gtv6 if im stuck with an iso trans
The problem with slop in from the shifter gate internally in the box and won't go away just because you get a more complicated linkage...
Changing the selector shaft is a 10 minute job if you have the boxes on the bench alreday. Maybe more if you need to let the sealant rest a while before bolting it up again.
The ratios on the speedgears are better on the 75 boxes, higher first and second maskes them somewaht usable.
Mats Strandberg -Scuderia Rosso- Now burned to the ground... -onemanracing.com- -Strandberg.photography-
GTV 2000 -77 - Died in the fire.
155 V6 Sport -96 - Sold!
Mats, new hairdo or What? Hey, I took Mats advice just recently. I got an '85 gearbox with the iso set up and I really wanted the 1 - 2 gear change. The iso set up is shit in my opinion and you have to pound a big ass frikkin dent in the undercarriage. Nice on paper though, but not the real world. I tried the iso and saw no substantial improvement and the articulating pieces just articulate to junk. It's more maintenance AND the consummable parts wil probably be NLA soon as well.
I've personally never been aware of a 75 gearbox here which I would have done. shortlife, go for the '85. You choose to use the iso or not. The gear change is worth it. Be advised, the '85 has a 4.10 rear ratio vs. 3.54 I think in the '82 & '83 only. You'll get more power to the ground with the '85; I know as I owned an '83 before. I like the 4.10. I also would no way go to a gearbox from a 4 banger that is that much older. However, again that's your choice. I think there are some clutch differences to consider as well if you go to the Alfetta.
Of course, now I'm thinking of selling my good '84 gearbox to make room. Too many spares for my cars.
