Alfa Romeo Owners Club of Australia Forum

Technical => 116 Series (Alfetta Sedan/GT/GTV & Giulietta Sedan) => Topic started by: mfroes on June 19, 2013, 09:22:48 PM

Title: GTV6 2.5 Gearbox suggestion
Post by: mfroes on June 19, 2013, 09:22:48 PM
Hi guys, i have a 1985 gtv6 2.5 with isoestatic gearbox and another problem i need to face is that my gearbox are in need of a rebuild. Needs new syncros for 1st, 2nd and 3rd.
Have ordered reinforced syncros to do the job and last longer as now that i have my childhood DREAM CAR i am not letting it go for yeaaaaars.

My question for you guys is:
I have read a lot that the 2L gears have a better ratio than the v6 version.
Should i go with the 2l ratio ? Even with the same 2.5l engine ?
If yes, are the syncros the same for both gearboxes ?
Should i just get a full gearbox from the 2l or just the gears ? What about the LSD on those boxes ?
Is it better for regular daily drive use ?

Any suggestions on where to get the parts if the 2l would be better ?
I know that is probably not the case, but cheap ?!?
Thanks in advance.
Title: Re: GTV6 2.5 Gearbox suggestion
Post by: rowan_bris on June 20, 2013, 06:41:36 AM
Having just put a fully rebuilt twinspark 75 gearbox into my GTV6, I would highly recommend going that way.  It is a significant improvement.
Title: Re: GTV6 2.5 Gearbox suggestion
Post by: Sheldon McIntosh on June 20, 2013, 12:57:05 PM
I think you'll find most people just transplant the whole Twinspark box, to get the different ratios and the LSD together. 

They pop-up occasionally, and the going rate seems to vary between about $800-$1500 depending on condition and whether or not it needs freshening up.

This image has a list of all the ratios.   http://img136.imageshack.us/img136/5782/alfaromeotransaxlegearr.jpg
Title: Re: GTV6 2.5 Gearbox suggestion
Post by: mfroes on June 20, 2013, 02:23:47 PM
taking under consideration i have already got the syncros and sleeves, i`d really preffer one to be rebuilt.
not one in "perfect" condition.

would the LSD be an advantage to road use ?
Title: Re: GTV6 2.5 Gearbox suggestion
Post by: mfroes on June 20, 2013, 07:50:32 PM
Hi guys,
I have seen this thread that says to swith to a 75 TS with lsd is not as easy as it seems.
www.alfaclubvic.org.au/forum/index.php?topic=7823.0

Would that be the case even for mine that is already aan 85 with isoestatic linkage ?
My speedo and tacho are fully electric.
Title: Re: GTV6 2.5 Gearbox suggestion
Post by: aggie57 on June 20, 2013, 09:11:25 PM
Quote from: mfroes on June 20, 2013, 02:23:47 PM
taking under consideration i have already got the syncros and sleeves, i`d really preffer one to be rebuilt.
not one in "perfect" condition.

would the LSD be an advantage to road use ?

To be frank in my experience the LSD itself does very little for a standard road car because the rear end is tied down so well; traction really isn't much of an issue other that tight corners in the wet taken with gusto. It can start to be a help if you run stiffer springs and sway bars as you start to pick up the inside wheel a bit more.

I say this as I ran a GTV6 box with an LSD for 10 years or so (actually 14 but for 4 years it sat in the garage).

On the track of course there is an advantage but then you'd probably have a bunch of other suspension and drive train mods so the direct comparison becomes harder.
Title: Re: GTV6 2.5 Gearbox suggestion
Post by: Beatle on June 20, 2013, 09:34:37 PM
Just rebuild your gearbox.  If you never drive another GTV6 with a TS gearbox, you'll never notice the difference  ;D  You won't have to muck about modifying anything to reinstall yours.   

Your childhood dream car never had a TS gearbox in it......  and if God thought the GTV6 needed it, it would have been so   8)
Title: Re: GTV6 2.5 Gearbox suggestion
Post by: scott.venables on June 20, 2013, 09:56:35 PM
A good compromise would be the 75 2.5 transaxle. Same gear and final drive ratios as the TS box but without the LSD.  You would probably pick one up for peanuts.  If you want to get the tail out you can always give it a flick........