slip yoke problem / TF 727

Hi Guys,

i bought a new slip yoke for my TF 727 trans. I´m not able to push this yoke into the trans, only light tapping with a hammer forces it in....to remove it also a hammer must be used. I did not push it in the whole way to avoid internal damage....what can cause this? I expect no problem with the trans, the car it came out shifted and drove properly.

Can anybody supply the correct outside diameter of a original mopar slip yoke to compare with this one?

Thanks for Info!

Michael