My daughter's 700r4 was recently replaced in her 91 5.0 z28. The speed drive gear on the output shaft is straight cut on the replacement unit. The speedo driven gear is slant cut; so of course the speedo doesn't work. I'm not sure which part was right for the car originally but I'm guessing the slant cut is right and the transmission recieved was not the right one for this car. The guy who installed the trans for her is nowhere to be found now. I'm not sure what to do now. Her speedo is electric, there are two wires in the connector, no cable. Can I use a straight cut gear on this speedo unit? Or can I get a different speedo? Or do I have to swap the transmission again? She just wants to sell the car but I think the speedo not working properly is causing some other issues, there is a slight miss, so I think I need to fix it before selling it. Any help is appreciated.

I'm guessing the driven gear is correct for your car?? If so..
If the reluctor isnt correct for your car, you will have to remove the drive reluctor wheel* from the outputshaft and install the correct drive gear and retaining clip for your rear end gear ratio. There is 2 holes on the output shaft for the retaining clip to fit in. make sure it sets the gear centered in the driven gear housing hole.

*(its just a press fit and some light taps from a hammer an brass punch will remove it)

Thanks for the input. The reluctor is steel. Is it still possible to tap off the steel gear? I can't get a punch behind it. I've put an adjustable wrench behind it, levered it against the cross member and whacked it with a hammer but it didn't budge. Any other ideas?

A slide hammer works. If you can get some heat on it that should make it a bit easier also..

Rent a gear puller from Oreilly's or whatever you have close by so you can get that gear off. Then you will need to figure out what drive gear you need based rearend ratio and tire size. I'm guessing the guy that R&R the transmission just swapped extension housings so you most likely have the right driven gear. Hopefully it's still usable. If not you should still be able to count the teeth so you can get a different one. I don't think you can buy them at the dealership, but they still might be able to tell you what gears you need if you give them tire size and gear ratio you have.

Thanks guys. The gear puller did the trick. Got it all buttoned back up now.