Transmission question

[jazz0000]

I have a 68 Charger with a 413 and 727 trans. I am trying to install the driveshaft but the slip yoke only goes about half way in and stops. It doesn't feel like it hits anything but gets too tight to go further. There are 30 splines on the output shaft and 29 inside the slip yoke with a slot that looks like 2 splines wide. I do not see a slot on the output shaft, is there one futher in on the other side of the seal? I have cleaned the slip yoke inside with trans fluid and a wire brush, is the tolarances that close? I don't want to hit it with a mallet to persuade it in fear that I will make things worse. I really don't want to buy another yoke if I don't have to. The slip yoke should go the full lenth in to allow room for the U-joint on the rear-end side to pass by for installation correct?

Any help is appreciated.
Thanks

[John_Kunkel]

Welcome to the board jazz.

There are reports that some aftermarket slip yokes just don't fit correctly, is yours new or used? Factory or aftermarket?

The missing spline in the slip yoke is to allow air to escape from the pocket at the rear of the output shaft.

[jazz0000]

The shaft and yoke is the original for the car, which had a 383 with a 727. Unfortunatly those were long gone when I got the car.
It could be that time and age has built up inside the yoke making things tighter that should be.
Thanks

[Ghoste]

I can add to what John says and report that some of those aftermarket ones that don't fit correctly even come from Chrysler.  I had the same situation with one that I bought through Mopar Performance.  To get one that worked I actually ended up using one from what we would more typically think of as an "aftermarket" company.

[idahogrumpy]

If the car was a 4 spd car or one that had a lot of power being put to the ground the yoke will twist at the splines. I did this to two yokes. (Yes my drive shaft should have been a touch longer.) Try another front yoke.    Kyle

[John_Kunkel]

If the year of the transmission is unknown, it's possible that the output shaft has a yoke seal that is incompatible with the slip yoke. In the pic below the shaft on the right has the seal installed, the front portion of the inside of the slip yoke must be sized for the seal.