Your problem seems confined to one of two parts and you should be able to handle the repair yourself with minimal research and basic tools. I'd say either the shift fork or the shift shaft has broken for 1 & 2 and I'd drain the transmission, remove the side cover and check. If you've a spot where you can disable it for a while that would be good.

If you can move the lever in the car and the rod for 1st & 2nd moves this is the area you want to concentrate on.

Look at the last image in this .pdf and this is the assembly where I believe you'll find your problem. Guaranteed? NO but it's where I'd start. Judging from your location I'd think there's likely a transmission shop that has the parts needed on the shelf or in an older parts box. There are parts all over the place.

http://www.lbfun.com/warehouse/tech_...2520Fisher.pdf

There are several assembly tutorials for the Warner Super T10 and there are parts available at many places. Many! You'll need whichever broke, some shift shaft seals and a cover gasket likely for the only parts to repair it. It will give you an opportunity to check the balance of the internals with the cover off. I would think this is an easy "in car" procedure. It might be to your advantage to do the detent ***** and spring while you're there also.

Daniel has just been there and he may be able to offer you some tips. It should be fresh in his "young mind". I believe the parts you need can be done several ways and the shift shaft if needed can be done less expensively than his was. I believe Daniel needed the 1st & 2nd shaft and his fork was OK. I don't recall.

Someone here might have a trashed unit and you could maybe buy the side cover assembly from it. I'd think that's very likely.

 

Yes there was a much simper and cheaper way to do it. I changed my input shaft bearing while I was in there because it was making noise. And I made the mistake of opening the over drive unit without installing the special bolts in the back. I did get the overdrive unit working 100%, and everyone brags about how tough it is to fix and no one wants to fix it, this and that, Yada Yada ya. But honestly, it was a piece of cake. Like I said before, just pop the side cover off before you do anything else and see what happened.

 

And if it's the shift shaft that broke, do not get a regular shift shaft for an older super 10. There is a notch in the shaft that a ball sits in. As you rotate the shaft, the ball rolls over the notch and turns on/off the first gear switch so that overdrive is not allowed to turn. I'm not sure which part of the shaft turns the overdrive off, but if you install an older style shift shaft it COULD make overdrive unusable. Or it COULD make overdrive usable in first gear. One or the other. SK Speed sells the correct replacement. Very nice people to deal with.

 

Daniel makes a good point here, I just checked and the 14081168 1/2 shift shaft is Corvette only. The fork is I'm quite sure '75 up.

I've bought manual trans parts from these people in the past and they've always done well.

http://kajunjon.com/

I'd try the parts section here first and post a WTB maybe. Never can tell maybe someone would offer up a "pass it on"!

 

Maybe an easy fix. You could of just have a broken or slipped off shifter inter-lock spring on the trans side cover. You say ur handy. This don't look hard. Check this Video out and pull your side cover off and check it out
If u do it. Take a little video with your cell phone and show us

 

It is the shift shaft broken I need them both the 3rd and 4th shaft looks bent and is worn. Is there supposed to be 2 ***** in that sleeve between the shafts? I only found 1 I also found a short 3/16 dowel pin is there more than 1? and where does it go?. If there's a diagram of the access door assembly that should be all I'd need. I've got a chiltons book and it doesn't show squat.

 

There should be 2 *****, 1 pin, and 1 spring. Put the pin in the spring and slide them through the hole in the cover. Then 1 ball on each side. They should sit between the two shift shafts. You can find the diagram by typing in Super T10 exploded view on google images. Put the transmission in the neutral position by adjusting the sleeves inside the trans. Assemble the shift shaft and cover assembly on the work bench. Then you can slip it on with ease. The shift shafts also need to be in the neutral position. I believe that both notches on each threaded part of the shaft should be vertical.

 

Thanks Daniel
You've been a great help calling around for a shifter shaft today and hopefully will back on the road Monday