TH400 driveshaft not going all the way in

[69 longhorn]

Originally Posted by clinebarger

Does the end of the output shaft have a threaded hole? If it does the splines on the output shaft are NOT machined all the way because it came with a bolt on yoke.

If this is your problem changing the output shaft with a fully splined one whould be the correct fix.

Also, be aware that your 64 did not come with a 400 turbo, & that trans is about 3/4 " longer than the old Power glide.If you are using a slipyolk(non bolt on) ,you need 3/4" minimum to 1" max on the slide(check with the weight on the wheels). best of fun,crazyAl