Changed trans awhile back and speedo stopped working- Pulled the cable tonight and checked everything out. What i found was the trans i installed has no drive gear... Obviously I neglected to check it before I installed the trans, but what now?
Does the trans have to come back out?

How difficult is it to install a drive gear?:(

Yikes!

The gear is pressed onto the tailshaft. When I rebuilt my old muncie a few years ago, I used the reverse gear as a slide hammer to drive it off, and heated it a bit and used a peice of the right size pipe to drive it back on. Wasn't hard with the tranny on the bench.

In the car will be somewhat less easy, mostly getting the tailshaft on and off. You'll have to support the engine or main tranny case, and probably get the crossmember out of the way. Shifter and linkage gone of course. I had a nice clean spot to guide me on where to put it. That part of the shaft is straight, and you jus gotta get it to the right place.

The tailshaft won't come straight off, you have to twist it to disengage the reverse fork. There's some parts in there that may come off and start bouncing around the garage, don't lose any.

Find a decent drawing of what's in there so you know what to expect.

I'd pull the trans and do the workbench trick. Gravity is working to your disadvantage under the car.

You have to get the right diameter, read number of teeth, of the driving gear, the gear on the output shaft, so the choices of driven gears will interchange without a problem. Testing the new combo on the bench is alot easier than under the car.

If you have a 4.10 or larger gear, a gearbox reducer for the speedo cable would be beneficial. P/N 3892220.

Sounds like a good candidate for a winter project.. Thanks guys..

You do not need to pull the tranny! Just the tail end housing (4 bolts). Drive shaft comes out first.
The plastic gear has a metal clip under it that has a tab that sticks into the output shaft that keeps the gear from moving. Once you figure out how that works just slide the gear off of the shaft. Some gears are kinda hard to "slide" on and may require a little force. Oh that's right, your's doesn't have one, then it should be easier going on than taking off. Here is a pic of the metal tab, lock, clip(whatever it's called) that goes under the gear.
The end that has one tab sticks into the shaft and the end with two points upward. You have to squeeze it together then slide it on.. http://i90.photobucket.com/albums/k264/pnewell44/000_1412.jpg

You do not need to pull the tranny! Just the tail end housing (4 bolts). Drive shaft comes out first.
The plastic gear has a metal clip under it that has a tab that sticks into the output shaft that keeps the gear from moving. You have to squeeze it together then slide it on.. ah, he has a manual trans and I believe they are press fit, not a slide-on and pin as an automatic trans.

I could be incorrect.

ah, he has a manual trans and I believe they are press fit, not a slide-on and pin as an automatic trans.

I could be incorrect.
oops, yep that would make a difference.

My muncie gear was steel, and pressfit.

So that being said...DO i need to to take the trans to a shop to have installed?

No, you can install it at home. Use a large diameter 1/2 inch brass drift punch and a hammer, and go about the gear at the base of it and tap it into place.

You might want to toast the gear in the toaster oven or griddle to aid on install. just be sure it doesn't go beyond where needed on the shaft.

Can someone point me in the direction of any instructions for removing the tailhousing and installing the gear? I have never torn down a tranny and could use pics if possible....