Central Shift w/ G50 box

[bigmack]

I would like to find out how other owners with central gearchange and a G50 transaxle have their shift rods arranged. My car has a very early design with the rods traveling down the right side of the chassis instead of the left and I have tried to minimize the angles on the rods. I am having a rather difficult time with upshifting from 2nd to 3rd at WOT. Its not too much trouble finding 3rd under normal driving conditions, but 3rd feels very close to 1st gear. I'm wondering if it will help to run the last rod coming off of the gearbox above the driveshaft rather than below it. It will increase the angle at the joint, but it may be more important to have the last rod running parallel to the chassis top rails. My thought is that this will keep the gearchange lever on the back of the box in more of a neutral position. Any advice or comments would be appreciated.
Thanks!
-Mack

[mkoch1]

When I was routing my gear linkage I found if the last rod wasn't parallel with the output shaft of the gear box all the gear where hard to find. My first attempt had the rod going under the drive shaft and then up to the gear box. Gear where almost impossible to find. I redid it so the last rod pretty much followed the factory set up and it is much better. My car is not done so I can't say how it will drive.

larger image

mark

[bigmack]

Hi Mark,
Thanks! I was hoping someone else had tried routing the last rod like you've done. All of my friends who own cill mounted gearchange units don't complain of this problem. I will try doing this and see if that work. My next question, is in what position do you line up the rods? Do you set the shift knob in the center and tighten the adjusting nut when the lever is centered in the 3rd/4th position? My central shift is real funkie. 1st and 2nd are inline with one another, then 3rd is mm's away from 1st, and then I've got 4th and 5th sort of inline with one another opposite of 1st/2nd. Reverse used to be real difficult to engage, but I think the reverse spring is loosening up a bit. It feels better now. I will change things up and see what happens. I'll report back. Thanks again!
Cheers!
-Mack

[mkoch1]

I believe when I set mine up I put the trans in neutral and held the shifter perpendicular to the floor pan.

mark

[bigmack]

Eureka! You were 100% correct Mark! Relocating the last shift rod above the driveshafts and more inline with the selector shaft on the back of the box is the solution. I sort of put this off thinking that it was a lost cause, but after hearing about your success with this I decided to follow suit. In the back of my mind I'd been postulating that solution. I changed things up last night and was able to use the stock rods. It felt soo much smoother and 3rd was evenly spaced between 1st and 5th. I gave it the WOT test today. No problems at all finding 3rd now! Thank you so much for that recommendation. We definitely need to spread the word to all of the fellows running central gearchange! Way to go!
Cheers!
-Mack

[k wright]

This really doesn't make any sense to me, but if it works then do it. It seems like the smallest angle at each u-joint in the linkage is the best way to go and this is what I used. So far so good, except reverse. Reverse has a lockout that requires a sharp smack to get past. If I just try to push the lever into reverse i can't get it in. If I slap it into reverse it goes right in.

Mack, put some more pictures up.

I'm still waiting on the stickers, I have saved everyones address that wants one and will send them when they will become available.

[bigmack]

Ken,
I think that having the last rod running in line with the gear selector is more important than the large angle created. It didn't make sense to me either. I was always trying to minimize the angles also, but the box just doesn't like having the last rod angled up to meet the selector shaft. If you think about a porsche, the rod runs straight back(the box is rotated 180 degrees towards the driver).
I had the exact same problem with reverse. I had to use two hands for a while just to engage it. It helps to sort of pull back slightly to get it into reverse as you get past the lockout. It feels a little better now with the new rod arrangement. The difference in shifting pattern is night and day though. Its much smoother engaging all the gears and I can finally find 3rd. There's was no way I could enjoy an autocross or track day the way it was previously. The great part about it was that I didn't have to cut or fabricate new rods. The old ones worked fine. Just remember to be sure and check your heim joint clearance in all gears.
Cheers!
-Mack

[mkoch1]

The best way to think about it is the shaft on the gearbox is meant to go strait in, out and twist left and right. If the last rod of the linkage is parallel with the out put shaft when you push forward on the stick the last rod pushes strait back. If the last rod is angled up when you push forward on the stick the last rod will be pushing back and up. Now your fighting the gearbox and the upward pressure will make it harder to slide the shaft into gear. Gets even worse when you add the side-to-side motion of the gearshift.

When we had my last rod angled way up, it took 2 hands to force the car into gear. Not to mention the fact that all the gears where rotated to the right. First was strait up where 3rd should be.

I guess I shouldn’t be surprised that the factory location of the last rod works best. I am sure they went through the same learning curve long ago.

Mark

[bigmack]

Drove the car again today. Gearchange is 100% better.
I forgot to mention in my previous post that my being able to select reverse gear has gone from two hands to two fingers! Much easier to engage reverse now.
Cheers!
-Mack