ALFAGTV6.COM

powderhoundcd · Post by **powderhoundcd** » Thu Mar 13, 2008 5:42 pm

Does anyone know the travel for the gear selector shaft (at the tranny)? I need to figure out both how far it moves in and out to select gears and how far it rotates each direction.

I'm working on a design for a short shifter and need to calculate the angles and lengths that I need in order to reduce the travel.

Also, I've seen diagrams of the GTV6 shifter and its casing (the one thats under the center console), does anyone have this?

Thanks a lot!

CD

sh0rtlife · Post by **sh0rtlife** » Thu Mar 13, 2008 6:06 pm

the trows are subjective to the arm length...if you change the length of the arm at the case its not going to travel as far..

then of course theres ISO vs "normal"

why not just go cable shift?

in and out i belive is about 1-1.5 inches

powderhoundcd · Post by **powderhoundcd** » Sun Mar 16, 2008 8:36 pm

Does anyone have any more specific information?

sh0rtlife · Post by **sh0rtlife** » Mon Mar 17, 2008 1:08 am

ive got one on the floor in the shop..i will try and get you "exacts" in the next day or 2....been down fairly ill....now where did i leave that micromiter

Mats · Post by **Mats** » Mon Mar 17, 2008 2:27 am

sh0rtlife wrote:the trows are subjective to the arm length...if you change the length of the arm at the case its not going to travel as far..

then of course theres ISO vs "normal"

why not just go cable shift?

in and out i belive is about 1-1.5 inches

At the box the travel and rotation is exactly the same on any 116 gearbox sinceit's a function of the distance between the gears and the internal shifter gate.

Cables are (IMO) an abomination and should not be considered.

sh0rtlife · Post by **sh0rtlife** » Mon Mar 17, 2008 12:52 pm

mats if you dont like cables..how would you fix the sloppy shift setup in such a way that it will NOT be sloppy for atleast 15 years?

Mats · Post by **Mats** » Mon Mar 17, 2008 1:22 pm

The "slop" you maybe feel in you shifter is perhaps in the linkage but fix that first and then think about the rest.

Now, My experience is that there is no slop. Whatever you think is slop in the linkage is actually the interior design of the shifter gate and you will not fix that with cables or any other redesign of the mechanics outside of the gearbox. It's there. Learn to deal with it.
Stop comparing the Alfetta feel of the lever to any late model gearbox like BMW, MX-5 or similar with a stick straight into the box because you will never ever get that feel in your alfetta box! (and really, who cares?!?)

So everyone, what is the damn problem? Can you actually not drive the car because you must move your hand the amount of travel needed to engage the gears? Can you honestly say that you missed a shift because you cannot feel the gate? Or is it the tech-buddy-approval you are looking for? Do you feel a powerful urge to have your alpha-male tell you that the gearbox feels tight and that the throw is nice and short?
If that is the case maybe you need to re-think your situation a little bit...

If you really feel the need to say that is impossible to shift it fast I have a ton of footage from inside my car that proves you incorrect, hell, I even have datalogs to prove it...

darryl longley · Post by **darryl longley** » Mon Mar 17, 2008 2:40 pm

I agree totaly
Ive never raced gtvs but ive run them for 20 years and have never had a problem changing gear
yes they are different but once you realise they are a transaxle and theres a linkage involved you get your head round it and it becomes second nature
make sure everything is fastened up properly and you shouldnt have any issues

Daniel · Post by **Daniel** » Mon Mar 17, 2008 7:25 pm

I'm with these guys.
If you want to shift faster, move your hand quicker but at least wait until the trans oil is warm.

Actually, if you have issues with the transaxle gear linkage it can be cured.
If you want less slop in the linkages, replace the bushes.
If you want a shorter shift, modify the lever ratio (shorten from the ball to the top of the stick, lengthen from the ball to the fork on the bottom of the stick).
If you want to go across the gate quicker, modify the selector finger.
You can taylor the shift to however you want (even without going isostatic).
I have set my shift up so it is firm and fairly short - probably comparable to an mx5 - with no slop at all. It feels like a stick in a box, not a long link setup.
or
You can go as far as MD went and redesign the entire linkage - his shift is so precise it feels like a rifle bolt (lots of work to get - not for easy for those with minimal mechanical skills & tools)

Even without modifying the shift length or cross gate, you can get a very precise shift as long as the link bushes, selector detents, synchros, etc are in good condition.

sh0rtlife · Post by **sh0rtlife** » Mon Mar 17, 2008 10:02 pm

dont get me wrong here guys i simply want to "improve" the feel..ive re-bushed the gtv6 and its better but still feels sloppy even compared to my 4sdp 68 cuda...when im talking about "slop" i mean put it into gear and how much does the shifter still walk around

imo going cable on my micro "project" should give me the ability to remove ALL slop not to mention limit the wearable parts..designed like im thinking it should net me some tuneablity in the feel and travel

that said...im leaveing the gtv6 shifter as is

powderhoundcd · Post by **powderhoundcd** » Tue Mar 18, 2008 7:48 am

I agree with everyone that the shifter feel is usable. I've been driving my car around and while it is true that I'm the only one in my family that can drive it, it's easily manageable.

Now, as for the project I was talking about, I'm attempting to come up with an alternative design, one that would be based on the original gear stick and would end up with a feel close to what I expect MD's shifter to be like.

I'm doing this design for my mechanical engineering class final so whether it actually works or not, I need to design one. But what I need is exactly how much the selector shaft rotates and moves in and out at the box. I would measure it myself, but the only transaxle that I own is currently in WA while I'm in Boston at school.

Other useful information would be the shifter length (below the pivot in the center console) and how much area there is to work with under there.

Thanks again for the help. CD

mjr · Post by **mjr** » Tue Mar 18, 2008 10:47 am

Slop?!! what Slop?!

if you still have slop in your trans after addressing the pivot ratio in the cockpit, and replacing the bush at the bottom of the stick in a non iso set up, then your transaxle is shit or you are using completely the wrong oil! There is no noticeable "slop" in the transaxle itself. if there is, there's something wrong.

I have 83 with totally stock trans, modified cockpit pivot ratio and very slightly shorter gate ratio on the fulcrum from the linkage to selector shaft (MD's budget mods. nothing touched on the trans) It feels as slop free as my 2 year old GM Astra sport. ie no slop. The trans was last rebuilt in 1999 on the GTV! once warmed up I can shift as fast as I like (with good synchros!). Its more baulky than the modern gearbox, i.e. I can't change gear with 1 finger on the lower gears, but thats no surprise, the modern box has light gearing.

Address the linkage issues, use the right oil, and thats all you need to do to lighten/shorten the feel by 35% and get rid of the factory inacuracy, you will get the best result that is possible, without cutting holes, bashing floor pans and totally re-designing the entire linkage with Getrag or something similar. If you have the money Lighten 1st, 2nd and 3rd gear too, that will help the synchro issue.

iso is another story, throw it in the bin.. go back to non ISO with above mods.. way better.

ok... so now flame me..

sh0rtlife · Post by **sh0rtlife** » Tue Mar 18, 2008 5:32 pm

in and out travel at the case is 1 inch give out take .5mm and when i say in and out i mean from say 1st to 2nd

so figure
-1/2inch is 1st
0inches is N
+1/2 is 2nd

trying to figure out the best way to degree out the rotation right now

at 1 3/4 straight up off the shaft at the transaxle it has 1/2 of travel...(was tricky finding something to mount to it and the best i could do gave me a reference point 1 3/4 inches at a 90 deg to the shaft..about as ideal as your going to get unless you want "stock" arm size or "iso" sizes)

1-2 = -1/4
3-4 = 0
5-R = +1/4

sorry i cant get you better measurements

i can probably get you some iso shift lever figures and parts figures...and might be willing to slide under the gtv6 for some as well.....i can say this...theres not much room in that tunnel

powderhoundcd · Post by **powderhoundcd** » Wed Mar 19, 2008 7:57 am

sh0rtlife,
does the diagram below look about right? let me know if I understood you correctly. Thank you VERY much!

CD

MD · Post by MD » Wed Mar 19, 2008 3:24 pm

I know you guys have seen my GTV6 street car shifter mods so there' no point in repeating myself. However for my Brick racer, I have made a variation on the theme.

It's only applicable to race cars as it will destroy the orignality of your street car so think this through. It is also more usefull for RHD cars as it uses up passenger seating room. But if you are desparate...

For what it's worth, here it is: (linkage photos in next post)

(Just remember that this is a PROTOTYPE and will be refined to reduce mass and make it look pretty-just trying to beat you off at the pass Matts

)

Gearbox Selecter Shaft Travel